PART I CYTOLOGICAL STUDIES IN ASTERACEAEshodhganga.inflibnet.ac.in/bitstream/10603/6506/7/07_part 1.pdf · CYTOLOGICAL STUDIES IN ASTERACEAE . ... 1999). However, cytogenetic studies,

PART I

CYTOLOGICAL STUDIES IN

ASTERACEAE

INTRODUCTION

The Asteraceae family is one of the most numerous within the Phanerogames.

This dicotyledonous family is widely distributed and constitute about 10% of

the entire population of flowering plants. The members of this family show a

remarkable diversity in hattit. Asteraceae has been thought to be at or very

near the peak of dicot evolution. This family is readily distinguishable from all

other families by the flowers aggregated together in head or capitulam. The

number of florets in a head varies enormously from several thousands as in

huge heads of some sunflowers, to a single flower, as in Echinops. where, the

single flowered head is hc~wever, generally associated in secondary heads.

Florets of a head is bisexual or unisexual (monecious or dioecious) or the

outer (ray florets ) female or asexual. Many members of the family are of

economic or medicinal value from the presence of ethereal and fatty oils,

resins and bitter princirles. Many indegenious plants are used as

grandmother's remedy for common colds, chills and fever.

Dumort (1822) was the first to propose the name Asteraceae and later the

International code of Botan cal Nomenclature approved that it can be used as

an alternative to Composita~:. According to Turner et al. (1979) the dispersion

centre of the family was probably South America. The plants are most

abundant in the tropical and temperate land but are also found in artic and

alpine regions. In India the plants occur in all possible climates and places but

are less common in areas under rain forests. They grow both in hills and plains

and play an important role ir vegetation.

The family is sub divided into two subfamilies viz, Tubuliflorae and

Liguliflorae, under the sub family Tubuliflorae 12 tribes are included viz.

Vernonieae (Vemoniaceae* ), Eupatorieae (Eupatoriaceae*), Astereae

(Asteroideae*), lnuleae (Inuloideae*), Heliantheae (Helianthoideae*),

Helinieae (Helenioideae*), Anthemideae (Anthemideae*), Senecioneae

(Senecionideae*), Calendulae (Calendulaceae*) Arctotideae (Arctotideae*).

Cynareae (Cynaroideae*) and Mustisiea (Mutisiaceae*) and one tribe

Cichorieae (Cichoriaceae*) under the sub family Liguliflorae (Bentham and

Hooker, 1883). The work fi)llowed here is on the basis of Bentham and

Hooker system of classification. Bentham and Hooker have placed the family

Asteraceae in their second order- the Asterales of Class Dicotyledones,

Division Gamopetalae and Series Inferae.

There is considerable difference of opinion regarding the number of

constituent taxa within the family. Lawrence (1956) recognized the Asteraceae

spread over 950 genera and 20000 species. Willis (1966) considered only 900

genera and 13000 species, where as according to Cronquist (1968) the number

of species included in this lamily is 19000. Jones and Luchsinger (1987)

represented by about over 20000 species, which are world wide in distribution.

140 of its genera and over 700 species have been reported from India. Fifty

two percent of the species art: endemic. In the world wide genus Senecio. the

largest in the family, with abcut 2500 species. Vernonieae is one of the 13

* name as in Flora of British 'ndia

pantropical tribe comprising more than 1500 species (Johri and Singh, 1997).

The Eupatorieae are a very diversified tribe and consists of more than 2300

species and 180 genera (Watanabe et al. 1995). The tribe lnuleae comprises

38 genera and around 480 species distributed mainly in Eurasia (Panchami

and Vijayavalli, 1998).

A majority of the plants are herbs - annual or perennial, some are shrubs, a

few are herbaceous or woody climbers, rarely trees. Majority are mesophytes.

Apart from mesophytes, sc~me occur as xerophytes, aquatic or marsh plants

and epiphytes. True water Aants are rare. Many taxas possess a milky juice

while in the other members the juice is watery, resinous and bitter. The tribe

Cichorieae is charecterised by a system of laticiferous vessels which

accompany the phloem tiaue; they are formed by the disappearance of the

transverse walls from longitudinal rows of cells and are also freely joined by

cross union. In the other lribes oil containing passages occur in the cortex

outside the vascular bundles running from the root through the stem and

generally continued in the leaf. The carbohydrate reserve material inuline is

dissolved in the cell sap of the roots and tubers of many members of the

family.

The remarkable success ol'the Asteraceae as evidenced by its great numerical

preponderance in genera and species over other families and the abundance of

many of its species, and its world wide distribution, it at any rate in part due to

the admirable adaptations of its flowers for cross pollination by a great variety

of insects (Rendle, 1938). Plentiful supply of easily accessible nectar. its

protection from rain, the close association of the flowers and the possession of

pollen mechanism, ensures c r x s pollination in the event of insect- visits. In

additon to these characters other factors are numerous small fruits produced

from capitulam and each of these fruits has direct aids to distribution by the

wind and water. They are chaffy character of small fruits , as in many

Anthemidea, or a covering of loose wooly hairs on the fruit itself or on the

bract; or more generally in the parachute development of the pappus.

The family is of great eccnomic importance. Several types of plants are

included in the family. Many plants possess medicinal properties and many are

grown as ornamentals. Coml~lex antibiotic preparations are also obtained from

some members of Asteraceile (Smimov et a]. 1995). Insecticides, oils. dyes,

and edible products are preoared from some members. The pharmacological,

medicinal, economical and other industrial uses of various taxa used in the

present study have been disc:ussed in the second part ofthe dissertation.

Genetic and cytological studies have been extensively carried out for more

than hundred years. Most >f the cytogenetic descriptions in the early stages

consists of informati01 only on the chromosome number without

morphological karyotype assessment of the group. Recently majority of

chromosomal and cytogenetical studies have been based on visible

characteristic of the chromosome. Karyotype analysis, a well established

method, is based on the morphological characteristic of chromosome and

widely used in cytogenetical analysis. The remarkable constancy of

chmmosome morphology ansj number within genera has been invaluable in

the study of plant systamatiss. In addition, many of the groups that have

distinctive chromosome nunbers are among the most readily defined

taxonamicaly. Therefore, it is attempted to find clue regarding phylogenetic

relationships through out the family by assessing chromosomal variations.

Polyploidy is very defused among plant species (Stebbins, 197 1 ; Grant, 1981 ;

Gill and Gill, 1994) and acsording to Lewis (1980) polyploidy and diploidy

have been important mechanism in the evolution of many plant groups.

Chromosome counting of same species may show different chromosome

numbers, from the distinct cytotypes of the species. Generally the

polyploidiied organisms have a great genetic plasticity due to a greater genetic

variability present in the genome (Mariano and Morales, 1999). However,

cytogenetic studies, such as determination of chromosome number and

morphology, along with bending patterns have been used increasingly in the

taxonomic determination of many species, where phenotypic or

morphoanatomic traits an: in sufficient to discriminate between species

Pioneering attempts on the cytology of Asteraceae are those by Tahara ( 1 9 15)

and Geisler (1931). Suffisient information is available on the members of

Asteraceae by virtue of the major cytological surveys conducted by Turner

et.al (1961,1964,1965) arid Mehra et al. (1965). Powell and PoweIl(1978)

recorded chromosome nurnbers of 100 species and 54 genera of Asteraceae.

Lawrence (1980); Adame and Falavera (1980); Luque et al. (1984); Jalals and

Pellinen (1985); Rabakonandrianiha and Carr (1987); Stahevitch and Wojtas

(1988); Husaini and Iwo (1990) Atlagic et a1.(1992); Endo and lnada (1992);

Tavassoli and Derakhshndesh (1993) Ayodele (1994); Strother and Panero

(1994); and Razaq et al. (1994); have also been made attempts in various

species of the family. However, almost all these cytological studies have

concentrated mainly on the determination of chromosome number and

provided scarcely any data on chromosome morphology and structure in

detail, nevertheless, this work laid the foundation for later researches.

Detailed karyotype analysi:; of Asteraceae members were carried out by

Khamdamov and Noskova I 1986); Jayaramu and Chanerji (1986); Ruas and

Ruas (1987); Chui et al. (1989); Watanabe et al. (1990); Qiao et al. (1990);

Herickhoff et al. (1 994); Branas et al(1994); Dagne (1995) Xiong et al. (1995)

and Arturo et al. (1996). Tlie study ofessential oil composition and karyotype

analysis are very meagre. Maffi et al. (1993) reported Essential oils.

chromosome numbers and Karyotypes from Achillea species. However, all

these karyomorphological studies mostly depended on the conventional

method.

Cytology is believed as a dependable tool for solving taxonomic problems and

for elucidating systematic relationships, phylogeny, and evolution of related

plant groups. The irformation like chromosome number, structure,

morphology and behaviol during mitotic and meiotic division have been of

considerable value in understanding inter relationships and delimitation of

taxa. (Yoshikane and Naohiro 1991). Therefore, these factors are used as

classificatory criteria in the same manner as the morphological characters:

since the chromosomes have direct relation to the genetic system of which

they are. an integral part ( Den Harlog et al. 1979).

In Asteraceae, chromosome numbers have provided to be of great value in

the determination of tribes (Naik, 1992). Raven et al. (1960) Raven and Kyos

(1%1) , Hair (1962), Omdui'f et al. (1963, 1967) Payme et al. (1964) and

Solbrig et al. (1964) have indicated that cytologically the tribe Helinieae is a

diverse group of various aftinities. The use of chromosomal characters in the

delimitation of genera can be seen in some Asteraceae members (Babcock,

1947).

Katyotype analysis have been useful in classifLing phylogenetic and

evolutionary relationship between some related species and species groups,

where differences in karyotyopes between taxa are not distinct, however, it has

been difficult to evaluate heir differences using conventional methods, and

interpretation of the differences have often been critized for lack of statistical

analysis (Watanabe et al. 1990). Several indices measuring karyotypic

differences are available i f homologies of chromosome and chromosome arms

are accurately ascertained (Duncan and Smith, 1978). It is hardly possible to

obtain definite evidence con chromosome homologies in plants, because G-

banding techniques are immature. Hence more objective method for assessing

karyolypic differences is needed. To answer this deficiency, in the present

study, it is used a numerical method for describing karyotypic difference or

similarities

In some Asteraceae members karyotype analysis is requiring the identification

of homologues are unreli:lble, because not all chromosomes can be

distinguished by their Length and cenhomere position, and no useful additional

cytological markers are avitilable (Koopman et al. 1996). Therefore the

karyotypes are established using numerical parameters describing the

chromosome length, area, perimeter, visual apparent three dimensional

volume, uniformity coeff11:ienf variation coefficient, disparity index of

chromosomes, total forma penentage (mean cenhomeric index value or TF%)

and number of discernible satellites. In some groups karyotypic differences

between species are largely quantitative and have been difficult to be assessed

by conventional quantitative methods.

Chromosome identification and mappings are indispensable in cytological and

genome analysis. There are limitation for the conventional measuring and

characterization of chromosome complement by visual evaluation, especially

for very small chromosomes. The ordinary karyotype analysis has provided

only limited success from the view point of chromosome identification, not

only in the plants with small chromosomes, but in many other plant species as

well (Fukui and Mukai, 15188). It had also been diff~cult to identify the small

chromosomes because of the similarity on the morphology at the mitotic

metaphase stage. In addition to that stainability of chromosome is not always

good. Only N and C banding methods are presently available in many cases,

these techniques, however, cannot always be applied. Therefore image

analysis of the chromoson~e by the chromosome image analysis system

(Fukui, 1985, 1986 a) wa:, employed in order to obtain data, which are

quantitatively accurate. Seniiautomatic karyotyping including numerical data

acquisition, pairing and arrangement of chromosome by digital manipulation

of the image using computer devices results in a detailed construct of

descriptive data (Fukui, 1988).

In the present investigation, karyomorphometrical analysis was conducted on

forty seven species of thirty four genera with the aid of improved techniques

(Sharma and Sharma, 198C; Fukui and Kamisugi, 1995). This study was

designed and aimed to bring out the Karyotype characteristic of different

species in the family Asteraceae and to check for marked symmetry or

asymmetry in the chromoiomal complements. The basic chromosome

numbers were employed in formulating phylogenenetic speculations and to

find out the direction of evolution in the family. Detailed

karyomorphometrical studies pertaining to chromosome length, area,

perimeter, volume, disparity index, variation coefficient and total forma

percentage are high- lighted n the present investigation in order to throw light

on the phylogenetic relation:,hip, the systematic position and affinities of the

different genera and different species of the family Asteraceae. This study is

also report original counts of chromosome numbers in Asteraceae and to

compare them with member; reported previously and to statistically test the

correlation between changes in chromosome number and karyotype. Further

an attempt is also made based on the previous and present cytological data to

decipher the inter relation:;hips among the various taxa to obtain a clear

understanding of evolutionay process at work in the family Asteraceae.

MATERIALS

Materials for the present stucy were collected from different localities, wild as

well as cultivated areas of South India. Forty seven species examined belong

to thirty four genera representing 9 tribes. Table - 1 show the collection sites

of the forty seven taxa used in the study. Voucher specimens are deposited in

the herbarium of Sacred Heart College, Thevara, Kochi, Kerala, South India.

1. Eleplantopus scabei- Linn.(Fig. 1 a)

The plant is a stiff sub - scapigerous herb with ohovate, oblong basal

leaves upto 16 cm long, narrow sessile cauline ones. Stiff heads with

purple flowers. Heads homogarnous of 2 - 5 flowers collected in a

head like clusters supported by 3 broadly ovate - cordate leaf bracts.

2. PhyUocephalum rutzgucharii (Gamble) Narayana.(Fig.2a)

( Centratherum ranpachurii Gamble)

Plant is an annul herb; stem loosely moniliform hairy, leaves alternate

4 - 9 cm x 1.5 - 3 c.m, ovate or elliptic - lanceolate. Heads solitary or

2 - 3 at tip of long slender peduncle. Homogamous.

3. Vernonia cinerea Less (Fig.3a)

This species is one of the commonest in Indian weeds. Stem slender,

15 - 17 cm high, g.ooved and ribbed. Leaves 2.5 - 5.0 cm; variable in

shape, broadly elli!~tic or lanceolate,

1 1

us. Flowers vinkish

and purple, in minute heads, in rounded or flat topped corymbs. Heads

homogamous.

4. Adenostemma lavenia (Linn) Kuntze. (Fig.4a)

The plant is an erect herb, stem, leaf viens and petals glandular

pubescent. Leaves 5 - 15 x 3 - 8 cm broadly ovate to elliptic -

lanceolate, Heads inteminal lax panicles, homogamous .

5 . A g e ~ t u m conyzoides L ~ M (Fig.5a)

The plant is an erect herb, annual, 30 - 60 cm, hispidly hairy, leaves

petioled, ovate crenate, heads small in dense terminal corymbs,

Homogamous flowers blue or white.

6. Ageratum haustonianwn Miller. (Fig.6a)

Herb to 1 m, annual, hairy. Leaves serrate, acuminate, corymb dense,

capitula blue. Flow(xs deep blue. (often higher altitude specimens of

A.conyzoides, with progressively larger and deeper blue capitula, are

confused with this sl~ecies).

7. Chromolaena odor~zta (Linn) R.Kig & H. Robinson. (Fig.7a)

(Errpotorium odoratum. Linn.)

Aromatic, erect, vis8:id -pubescent sub shrub to 3 m. Leaves opposite,

simple obovate, to deltoid ovate, acute, crenate, serrate, sub palmately

3 nerved. Capitula corymbose, stalked. corolla white to purple.

Flowers homogamc~us.

8. Eupoforium trblinenve Vahl. (Fig.8a)

(E.ayapana Vent.)

An aromatic under shrub, 0.9 - 1.2 m high with trailing stem, rooting

at the nodes. Subsessile lanceolate leaves and lax corymbs of bluish

flower heads. Flower!; homogamous.

9. Mikania cordata (Bu1m.F) Robins. (Fig.9a)

( M. scandens, Willd.:~

The plant is a climbing shrub, leaves long petioled, ovate, acute or

acuminate base rounded cordate or truncate crenate or angled. Some

times villous beneath. Heads 4 flowered corymbose terminating lateral

branches, homogamous.

10. Conyza bonariensis (Idinn) Cronq.(Fig.lOa)

Sericeous herb. Leaves linear - lanceolate, hirsute above and below,

margin entire to sparingly serrate, sub sessile, panicles terminal lax

racemose, capitula cre Im.

1 1 . Conyza canadensis (Linn) Cmnq.(Fig. l la)

It is an annual plant with an erect branched stem, densely covered with

narrowly lance-shapea leaves, and bearing many flower heads in dense

clusters. Each flower heads has many central tubular disk florets and

several outer rows of ray florets. Both are yellow and white.

.? a- : * - 12. Dichrocephala chrysanthemifolia DC.(Fig.l2a)

The plant is an annual herb. Leaves alternate, sessile, auricled at base,

obovate, heads very small, panicled, heterogamous globose, not rayed.

13. Erigeron mucronatus DC.(Fig. 1 3a)

The plant is an annual herb. Leaves narrow linear. Head

heterogamous and rayed. Corollas of ligulate flowers narrow, white,

pink or purple.

14. Blmea lacera DC. (Fig.l4a)

Strongly scented her11 to 75 cm, glandular pubescent, interspersed with

eglandular hairs. Leaves elliptic oblanceolate, 2.5 - 6 x 1.3 - 3.5 cm

capitula 5 - 7, shortly stalked in dense corymbose, spiciform, panicles

terminating the branchlets. Corolla yellow in disc florets.

15. Blumea mollis (D.Don) Merr.(Fig.l 5a)

Villous silky hairy, !items erect sub simple very leafy, leaves petioled,

obovate, irregularly toothed. Head 0.6 cm collected into terminal

spiciform dense cymcs. Heads heterogamous. Corolla purple.

16. Blumea oxyodonla 3C.(Fig. 16a)

Low herb with several ascending branches. Leaves radical and cauline,

thinly scabrid above, softly pubescent below, capitula paniculate,

shortly stalked,bisex~lal florets, corolla yellow.

17. SphaeMntksrs indicus Idinn. (Fig. l7a)

The plant is an annual herb with spreading branch, leaves alternate,

toothed, decurrent on the stem. Heads small heterogamous not rayed.

Pink or purple flowe~s, collected together in close terminal globose

clusters.

18. Vicoa indira DC.(Fig.l8a)

Plant is a herb. Leav:s alternate, sessile, oblong, lanceolate. auricled at

base. Heads heterogmous, rayed, solitary, terminal or leaf opposed.

Yellow flowers.

19. Acanthospermum hispidum DC.(Fig. l9a)

Erect branched, h~spid-hairy plants. Leaves obovate, spathulate

palmately veined and alternate. Heads solitary sessile, yellow.

Involucral bracts (outer) ciliate. Achenes with many, hooked, lateral

spinules and two s might apical spines.

20. Bidenspilosa Linr .(Fig.20a)

The plant is a ver/ variable erect herb, leaves 3 fid - 3 foliate. Heads

on long stout peduncles very variable in length, with white rays.

Heads heterogamous

21. Cosmos b@innalus Cav. cv. Orange.(Fig.2la)

Tall herbs, to 80 cm high, leaves 2 - 4 pinnatisect. lobes entire,

glabrous, 7 - 8 1:m long. Peduncle long ligules orange red to yellow,

sometimes white; disc florets orange in colour. Grown in gardens,

occuning as escape ancl naturalizing in plains and upper ghats.

22. Cosmos bipinnaius Cav. cv. Yellow.(Fig.22a)

Erect herbs, leaves lorig, opposite, bipinnatisect, petioles upto 2.5 cm

long sheating at base, tleads terminal, Disc florets yellow.

23. Cosmos caudalur Kunth.(Fig.23a)

Erect annual herb 0.5 - 1.5 m tall. Leaves bipinnatisect or some what

tripinnatisect, pinnuk:~ opposite, capitulam solitary, axillary or

terminal, long stalked, heterogamous,wrolla purple.

24. Ecliptaprosiraia (Linl~) Linn.Vig.24a)

The plant is an annu:~l herb with small flowers. Leaves lanceolate,

oblong and strigose. Branches erect or prostrate. Leaves opposite.

Heads small, heterogarnous with white ray florets.

25. Golinsogaparvifora Cav. (Fig.25a)

The plant is a weak, erect glabrous herb, annual branched stem and

simple opposite leave:; bearing stalked clusters of flower heads in their

axils. The small flow.:r heads are formed mainly of yellow disc florets

with a few white ray florets.

a 1 9a Acuni/~o.iperrnum hupufvrn 20a Brdem pilaur, 2 l a. ( ' a m h ~ p i m ~ m cv. mange, 22a ( b s m bspinmw m. yellow, 23a C o s m unahtw, 24a lidlipru proIytrata. 2 k. ( ialiit.qa pnvflwq 26a Melampoth urn puludann. ?7a Purihenium hyteruphore.~. =

26. Melampodiumpaludosnr B.H.& K. (Fig.26a)

This is an annual herb with profuse dichotomously branched stem.

The leaves are opposite: and ovate. Flower heads are star-like, lemon

yellow in colour with a raised orange to brownish central disc.

27. Parfhenium hysteropht>rus Linn.(Fig,27a)

The plant is a herb. 1.0 rn in height, stem long; tridinally grooved,

leaves irregularly dissrzted, head is corymbose head; homogarnous

white flowers.

28. Sigesbeckia oriental& Linn.(Fig.28a)

A large annual herb ~ i t h yellow flowers and large ovate-triangular

deeply cut leaves, the lower heads glandular and very sticky, adhering

to the clothing. Leav:s opposite, toothed, shortly petioled. Heads

heterogamous, rayed.

29. Spilanthes caba Dc.(I:ig.29a)

The plant is a herb, occurring through out the greater parts of lndia.

Stem erect or decumbent at base, leaves opposite, ovate-lanceolate,

dentate or almost entire, florets yellow in solitary or sub solitary long

peduncled conical heads. Flowers homogarnous.

30. Spilanthes ciliata H.6.K (Fig.30a)

(S. acmella Murr.)

Diffuse herbs rooting at lower nodes. Stem terete. Leaves to 7 x 4 cm

ovate, base rounded cr sub cordate margins serrate, apex acute, petiole

1 - 2.5 cm long. Heads rayed axillary, usually solitary, rarely 2 -3 in

each axil, turning cortical, yellow, peduncle 3 -8 cm long. lnvolucral

bracts 2 seriate shorter than ray florets.

3 1. Spilunthes radicans Jacq.(Fig.3 I a)

Erect herb, stem minutely pubescent. Leves to 7 x 4 cm ovate, base

obtuse, margins faimly serrate or entire, apex acute, petiole 1 -2 cm

long. Heads axillary, solitary 5 - 8 mm. across discoid, white,

peduncle 4 - 7 cm lor~g.

32. Spilanthes uliginosa Sw.(Fig.32a)

This plant is a very common creeping herbaceous weed. The flower

heads are conical and solitary on peduncles, yellow in colour,

heterogamous ray florets few.

33. Synedrella nodifrora, Gaertn.(Fig.33a)

The plant is an erect dichotomously branched herb, stem and branches

terette, glabrous, leaves ovate lanceolate, shortly petioled serrate,

scaberulous, 3 nerved. Heads sessile, axillary and terminal. Heads

small heterogamous, flowers yellow.

34. Tithonia diversifolia ,\.Gray.(Fig.34a)

The plant is a large shrub. Leaves petiolate and dissected (palmately

compound). Heads large, heterogamous and rayed, yellow.

35. Tridaxprocumbens Linn (Fig.35a)

The plant is a weak ztraggling herb 30 - 60 cm long with few leaves

2.5 - 5 cm long and very long slender solitary peduncles 25 cm long

and more. Head 2' cm diameter. Heads very long peduncled

heterogamous ,rayed, ray flowers white.

36. Wedelia chinensis (Osbeck) Merrill (Fig.36a)

(W. Calendulacea Le:;s.)

It is a climbing shn~b. Leaves linear-oblong or oblanceolate, sub

sessile, entire, roughly scabrous, heads solitary on slender axillary

peduncles 5 - 12.5 1:m long. Head heterogamous with yellow ray

flowers.

37. Wedelia frilobata (Lirn) Hitch.(Fig.37a)

It is a climbing s h r ~ b scabrid pubescent or hirsute herbs or under

shrubs, leaves opposite, trilobed often triple nerved. Heads

heterogamous rayed, axillary or terminal, radiate, yellow flowers.

38. Zinnia elegans Jacq.(Fig.38a)

Erect herbs. Leaves :~.5 - 10 x 1.5 - 5 cm, opposite, ovate, elliptic

ovate or ovate - oblorg, scahrid obtuse or subcute, 5 nerved from the

base. Heads 5 - 8 cm cross, pink, terminal, solitary.

39. Tagetes ereda Linn cv. orange.(Fig.39a)

A stout branching herb, 60 cm tall, leaves strong scented, pinnately

dissected segments 1 - 5 cm long oblong or lanceolate, serrate, flower

heads solitary, orange in colour,rays many long clawed.

40. Tagetes erecta Linn cv pale yellow (Fig.40a)

Stout herb, tall, native to Maxico extensively cultivated in gardens all

over India. Flower heads solitary .Flower heads yellow in colour.

41 Tagetes ereda Linn I:V Yellow. (Fig.4la)

Leaves strong scented, pinnalely dissected. Flower heads solitary

yellow in colour.

42. Tagetespatula Linn. (Fig.42a)

Sub shrub to lm. Stem dark red in colour .leaves aromatic, alternate,

pinnate, capitulam solitary, terminal or axillary, heterogamous, corolla

orange red in colour.

* - 37a Wedeliu rriiobuiu, 38a. Z~nniu elegans. 39a Tageles erecia cv.orunge, @a. 7agefe.s ereom cv. polf yellow. 41a. lagetes erect0 c v . ~ Y e l l ~ ~ , 42a. , I , ugeies piiltdu, 43a. ('hrysanthernum pur~henium, 44a. ('&.r.r~~'e~haIurn

crepIiliide,s. 4 5a. Enrilia sonch$ioIiu.

43. Chrysanthemum parthenium (Linn) Benth.(Fig.43a)

This medium high, densely branched and leafy plant attracts attention

by its distinctive aroma. The stems are erect, bearing many soft much

dissected leaves and t-rminated by clusters of flower heads. These

are small with yellow tubular florets in the center and white ray florets

around the outside.

44. Crossocephalum cwpidioides (Benth) S. Moore.(Fig.44a)

Stout herb to 1.5 rn, branchlets striate, brittle, leaves ovate to

oblanceolate (lower part pinnatipartite) base attenuate to decurrent,

margin coarsely dentate, petiole to 8 cm, capitula, 1.5 crn across.

Florets brick red.

45. E& sonchifolia (],inn) Dc.(Fig.45a)

The plant is a small herb, stems and leaves soft, fistular, glauceous,

glabrous or nearly so, the leaves lyrate pinnatifed with large terminal

lobe, upto 10 cm lsmg the basal leaves petioled cauline, accurately

auricled corolla lobes very short. Head small. Homogenous.

46. Notoniagrandiflru Dc.(Fig.46a)

Plant is a fleshy shrub reaching 1.5 m in height, with pale yellow

flowers, turning green. Leaves obovate or oblanceolate or sub

orbicular, obtuse, vwiable in size but some times reaching 17 cm long

and 8 cm broad, quite entire glacious green heads 2.0 cm - 3.0 cm

long. Head large, homogamous not rayed all bisexual in long

peduncled corymbs.

47. Sonchus oleraceus Lilm.(FigA7a)

It is an annual plant with an upright hollow stem. Leaves radical in

young plant, in mature plants they are cauline, exstipulate, sessile and

auriculate. Inflorescer~ce bearing several umbellate heads which are

homogamous, flowm are yellow in colour.

Table 1: List of members investigated

Serial Name o f taxa Locality of collection Altitude in No. meter (approx)

1 Elephantopus scaber Neriyamangalam 65

2 PhyUocephalum rangacharii Malliyankara Sea level

3 Vernonia cinerea Kochi Sea level

4 Adenostemma lavenia Malliyankara

5 Ageratum conyzoides Kochi

Ageratum haustonianum Munnar

Chrodaena odoraia

Eupatorium triplinewe

Mirkonia cordata

Conyza bonariensis

Conyza canadensis

Dichrocephala ch~ysanfht~m~olia

Erigeron mucronatus

Blumea lacera

Blumea mollis

Blumea oxyodonta

Sphaeranthus indicus

Vicoa indica

Acanihospermum hispidum

Bidens pilosa

Kochi

Aluva

Kochi

Kochi

Neriyamangalam

Munnar

Munnar

Kochi

Kochi

Kochi

Thrissur

Thrissur

Vandanam

Munnar

2 1 Cosmos br$innatus cv. orange Kochi

22 Cosmos bipinnatus cv. yellow Kochi

Sea level

Sea level

I050

Sea level

10

Sea level

Sea level

65

I050

1050

Sea level

Sea level

Sea level

80

80

Sea level

1050

Sea level

Sea level

Cosmos caudatus

Eclipta prostrata

Galinsoga pawiflora

Melampodium paludosm

Parthenium hysterophorus

Sigesbeckia orientalis

Spilanthes calva

Spilanthes ciliata

Spilanthes mdicans

Spilanthes uliginosa

Synedrella nodiflora

Tithonia diversifolia

Tridax procumbens

Wedelia chinensis

Wedeli0 trilobata

Zinnia elegans

Tagetes erecta cv. orantre

Tagetes erecta cv. pale e ell ow

Tagetes erecta cv. yell0 u

Tagetes patula

Chrysanthemum parthenium

Crassocephalum crepidioides

Emdia sonchifolia

Notonia grandifora

Sonchus oleraceus

Kochi

Kochi

Munnar

Kochi

Alapuzha

Munnar

Munnar

Kochi

Neriyamangalam

Malliyankara

Kochi

Munnar

Kochi

Angamali

Kochi

Munnar

Kochi

Kochi

Kochi

Munnar

Munnar

Kochi

Kochi

Kochi

Munnar

Sea level

Sea level

I050

Sea level

Sea level

1050

1050

Sea level

65

Sea level

Sea level

1050

Sea level

Sea level

Sea level

1050

Sea level

Sea level

Sea level

1050

1050

Sea level

Sea level

Sea level

1050

METHODS

a) Mitotic squash experiments

The cytology of Forty s e v e ~ species belonging to thirty four genera from

South India was investigated with the help of improved cytotechniques

(Sharma and Sharma 1980). Squash experiments were carried out on root tip

meristem at mitotic metaphase stage. The root tips are collected from the

plants of various species planted in the experimental botanical garden at the

periods showing peak mitotic frequency, i.e, 9.00 a.m. to 1 1 a.m. The root tips

were pretreated with saturatecl solution of para dichloro benzene with traces of

aesculin for 3 hours. It is fcund to be most suitable for many members of

Asteraceae. Eventhough 0.0(14 M 8 - hydroxy quinoline at 18 to 20°c for 2

hours is also used for some genera like Notonia . The root tips immersed in

cytostatic chemicals are initially chilled at 0-5% for 4 - 7 minutes and then

kept at 12 - 20% for I - 3 hours for obtaining best results.

The pretreated root tips are then washed thoroughly with distilled water and

fixed in 1 : 3 acetic acid - ethyl alcohol mixture (Carnoy, 1886) overnight,

followed by 3 - 7 minutes reatment in 45% acetic acid. Root tips were

hydrolysed in IN Hcl at 60% for 5 - 7 minutes and squash preparations were

made in 1% acetoorcein (Shanna and Sharma, 1980). The apical 0.5 - 1.0 mm

root tips were cut and placed on slide, squashed gently with a needle in 45%

acetic acid and covered with cover glass. The preparation was temporarily

sealed.

b) Meiotic smear experiments.

Pollen mother cell (PMC) analysis were carried out on those members which

bloomed frequently in the experimental garden. Young flower buds of 10 - 12

days old were picked b e t w ~ ~ n 9 a.m. and I 1 a.m. each day and fixed in

Carnoy's fluid (6:3:1 Ethanol, Acetic acid, and chloroform) for 12 hours. The

next day anthen were washed three times in distilled water and stored in 70%

Ethyl alcohol. Squash preparations were made in 1% aceto carmine (Shanna

and Shanna 1980).

c) Detailed karyomorpbologieal studies by image analysis system.

Pbotogrnphs and image processing

Well spread metaphase plates were photographed using 125 ASA 35 mm

Orwo film in a Lei& photc~graphic attachment and suitably enlarged. A 200

dpi scanner scans each original photograph. The software Adobe Photoshop

was used for digitalizing and reproduction. The contrast of each image has

been increased by raising the resolution upto a satisfactory level. Acquisition

of quantitative data from large number of plant chromosomes and also semi

automatic karyotyping can be easily carried out by using image analysis

system. The generated mages were checked by the visual inspection

comparing with the original photo micrographs. After storage of original

digital images of the metaphase spreads in floppy discs, these images were

analyzed by using compllter devices. The image was recovered from the

floppy disc and the original digital image for the analysis was then generated

automatically. A binary imabe that was essential for the object identification

by the computer was generated by interactive setting of the lower and upper

thresholds of the gray levels These thresholds were defined properly so that

the gray values of the pixels that consisted of chromosome images were

included. Binarization was iutomatically carried out by changing the pixels

values stood between the two thresholds to white and all other to black. The

large background dust particles and spots whose gray values also fell between

the two thresholds were elin~inate by adjusting the gray values of the pixels

outside the chromosomal region by interactive setting of lower and upper

thresholds of the gray levels. This will result in a binary chromosomal image

with a clean background.

Quantitative karyotyping of the chromosomes.

Measurement of each chroinosorne from enhanced image were made by

AutoCAD (Version2000) loaded on a personal computer. This image was

automatically coloured differently by the computer generated colouration

based on the actual gray values of the pixels. Pseudocolouration considerably

improved the density distribution of the objects and the recognition by

humans. This will help to detect the primary and secondary constriction of the

chromosomes. These constrictions were namely marked by the overlay

straight lines on the pseudocoloured images. After this midrib lines were

drawn interactively on eact chromosome. Extraction of the midrib lines,

breakage at the position of the constriction and identification by different

Fig. 1

Fig. 1-9: Different steps of karyotype analysis by the image analysis systems. 1 - metaphe plate, 2 - binarization, 3 - background cleaning, 4 - metaphase plate with clear background, 5 - selsction of a chromosome for measurement, 6 - enhanced image with marking in the constriction, 7 - drawing marginal line, 8 - differentiation by applying various colours and 9 - midrib lines.

colours were subsequently carried out automatically. The outer margin of each

chromosome image also marked t!y drawing surrounding line. Numerical data

such as the arm length, area, perimeter and an apparent visual three

dimensional volume of each chromosomes were obtained in pixel units. In all

the karyotypes, ratio of the short arm to the total length of the chromosome in

percentage, Forma percentage or centromeric index (F%) is determined after

Krikorian et a1 (1983). On the bmis of F% the nature of primary constriction

in the chromosomes are classifietl as follows:

Nature of primary constriction

Mc:dian

Ntarly median

N~:arly sub median

Sub median

Nearly sub median

Nearly sub terminal

Sub terminal

Irlearly sub terminal

E.xtremely sub terminal

Terminal

The values obtained for the ch~.omosome morphology were:

Total arm length of each chromosome (long arm length + short arm length)

and relationship of the arm (R3)

RB is calculated by the following formula

RB = long arm length 1 short arm length

Arm ratio (AR) has been widely utilized for the classification of chromosome

types (Leven et a1.1964) has been considered empirically to be a more stable

parameter of the chromosomal morphology. The AR was defined as the ratio

of the length of the short arm to that of the long arm (SiL) for each

chromosome.

The following indices were also calculated for each chromosome is

determined after Watanabe et d. (1 990)

2ai Relative long arm length (RLI,) = 2n

Z (aj+ bj) j=l

2bi Relative short arm length (RS L) = -57-

1 (aj+ bj) j=l

Relative chmosome length (RL) = RLL +RSL

Arm difference ratio (AD) = (ai - bi)/ (ai + bi)

where ai = long arm length o Fchromosome i, bi = short arm length of chromosome i, and

2n

C (aj+ bj) =total diploid chromosome length j=1

The disparity index (DI) of chromosome in a karyofype is calculated after Mohanty et a1.(1991) by the f3rmula:

longest chromosome - shortest chromosome DI = x 100

longest chromosome + shortest chromosome

The variation coefficient among chromosome complements (VC) is determined after Verma (1980) as follows:

standard deviation vc = - x 100

mean lengths of chromosome

The total forma percentage or the mean centromeric index value (TF%) is calculated in each taxa after Husiwara (1962), by the formula.

Total sum of short arm length TF% = x 100

Total sum of chromosome length

The uniformity coefficient ([erimeterlarea) (Ojeda and Torres, 1996) were

also calculated. All the numerical data are prepared after comparing at least

five well spread metaphase plates. The various calculations were done by the

computer package Microsoft Excel

Quantitative idiograms of chromosomes

Based on the data relating to the length, the idiograms were presented

combined with the results of quantitative image analysis of chromosomes.

The chromosomes were arranged semi automatically according to the length,

arm ratio, uniformity coefficient, three-dimensional volume and idiograms

generated with the aid of computer software Adobe Photoshop.

OBSERVATIONS

In the present investigation 47 taxa of 34 genera were analysed. The normal

somatic chromosome number ranges from2n = 10 to 2n = 78. However,

numerical variations are previilent in some taxa. The ploidy level exhibited by

different taxa ranges from diploidy to hexaploidy. The chromosome pairs

with secondary constriction are found to range from one to four. The

karyotypes are characterised by comparatively small chromosomes ranging

from 0.41 pm to 2.54 pm in length. The chromosomes in each karyotype

decreased in size progressiv~:ly and they had nearly median to nearly sub

median primary constriction.

The general description of the common chromosome types is given below

followed by the karyotype deszription of each of the members investigated.

Type A: Comparatively long chromosomes with two constrictions, one median

to nearly median and the other nearly sub median.

Type B: Relatively long chron~osomes p0.8) with nearly median to nearly sub

median primary constriction.

Type C: Small chromosomes (<0.8) with nearly median to nearly sub median

ptimary constriction.

Figs. I b, l e - Elephanropus scuber : I b - mitotic rnetaphase (2n=22), le - meiotic ~netaphase (n=I I ) ; 2b.2e - Phyliocephalum rangacharii : 2b - mitotic metaphase ( 2 ~ 1 8 ) . 2e - meiotic metaphase (n=9); 3b,3e - Vernonia cinerea : 3b - mitotic rnetaphase (2n=18), 3e - meiotic metaphase (n=9); 4b - Adenostemma luvenia mitotic metaphase (2n=20); 5 b . 5 ~ - Ageralum conyzoides : 5b - mitotic metaphase (2n=40). 5c - somatic variant ( 2 ~ 3 0 ) ; 6b - Ageruturn hausronianurn mitotic metaphase (2n=40); 7b Chromolaena odorara mitotic metaphase ( 2 ~ 6 0 ) ; 8b - Eupatorium lriplinerve mitotic metaphase (2n=50); 9b,9c,9e - Mikania cordara: 9b - mitotic rnetaphase (2n=36), 9c - somatic variant (2n=34); 9e - meiotic metaphase (n=18); lob - Conyza bonariensis mitotic metaphase ( 2 n ~ 5 4 ) . Bar represents 5pm each

Elephantopus scaber

Nomal somatic chromosome number

Karyotype formula

Number of chromosome pairs with secondary constriction

Range of chromosome length in pm

Total chromosome length in prn

Average chromosome length in pm

T.F. value (%)

Variation coefficient (VC)

Disparity index (Dl)

Total volume of chromosomes in umf

2n = 22 (Fig. I b) A2 86 C14 1

1.1 1-0.63 17.88 0.81 45.74 18.75 27.58 0.72

Table 2: Detailed karyotype analysis of Nephanlopus scaber

Total Short arm

Type length length F in pm in um

Nearly sub median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Normal somatic chromosome number

Karyotype formula

Number of chromosome pain with semndarr constridon


Total chromosome length in urn


T.F. value (%)

Variation coefficient (VC) Disparity index (D.1)

Total volume of chromosomes in pm'

Table 3 : Detailed karyolype analysis of Ph!fllocephalum rangachsri

Short Total arm Volume p,A

A? 4D RE F % inpm, Nature of primary

Type length length RL ratto constriction in pm in pm

A 1.14 0.37 0.11 0.84 0.09 1.19 32.84 0.0210 2.64 Nearlysubmedian 0.32


B 0.82 0.38 0.11 0.87 0.07 1.15 46.41 0.0229 3.54 Nearly median

B 0.81 0.35 0.11 0.78 0.13 1.29 43.73 0.0199 3.01 Nearly median

C 0.77 0.36 0.10 0.88 0.06 1.14 46.80 0.0195 3.02 Nearly median

C 0.76 0.34 0.10 0.81 0.11 1.24 44.85 0.0106 3.87 Nearly median

c 0.73 0.35 0.10 0.90 0.05 1.12 47.28 0.0162 2.82 Nearly median

C 0.72 0.35 0.10 0.98 0.01 1.02 49.46 0.0199 2.94 Nearly median

c 0.67 0.31 0.09 0.88 0.06 1.14 46.78 0.0130 3.74 Nearly median

Vernonla cinerea


Karyolype formula

Number of chromosome pairs with seo~ndary constriction


Total chromosome length in pm

Averege chrommme lmgth in pm

T.F. value (%)

Variation coefficient OJC) Disparity index (D.1)

~ o t a l volume of chromosomes in pm'

Table 4 : Detailed karyolype analysis of Vemonia cinerea

Short Total a, Volume P,A Nature of primary

TYW length lensul Arm AD RB F % in pm, RL ratlo consttiction

in pm . ~n pm

A 1.29 0.47 0.11 034 0.03 1.07 36.09 0.0505 2.66 Nearlysubmedian 0.33

Nearly sub median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median


Karyotype formula

Number of chromosome pairs with secondact


Total chromosome length in vm

Average chromosome length in Urn

T.F. value (%)


Disparrty index (D.1)

Total volume of chromosomes in um'

2n = 20 (Fig.4b)

A2 818

constriction 1

1.53 - 0.92

23.02

1.15

44.39

35.1

24.89

1.4

Table 5: Detailed karyotype analysis of Adem,siemma lavenia

Shod Total am

Type length Volume RL Am AD RE F% In pm, PIA Nature of primary length ratlo constriction

In pm ln urn

A 1.53 0.59 0.10 1.00 0.30 l .W 38.67 0.0681 3.02 Nearly median 0.35

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Neatly median

Nearly median


Kalyotype formula

Number of chromosome pairs with sewndarl constriction




T.F. value (%)




Table 6 : Detailed karyotype analysis of AgJemtum wnyzoides

Short Total arm Arm Volume

4D RB F% inpm3 P/A Nature of primary Type length length in pm RL ratio constridion

in pm

Nearly submedian

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Ageratum haustonfanurn

Normal somatlc chromosome number

Karyotype formula





T.F. value (%)


Disparity index (D.1)


Table 7 : Detailed karyoptype analysis of Ageratum haustonianum

Short Total arm

Type length length in pm

in um

Arm ratio

Volume F96 in ~ m '

Nature of primary constriction

Nearly sub median

Nearly sub median

Nearly median

Nearly median

Nearly median

Nearly median

Median

Nearly median

Median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Chnamolaena odorab


Karyotype formula

Number of chromosome pairs with secondary ans strict ion

Range of chromosome length in IJm



T.F. value (%)



Total volume of chromosomes in urn'

Table 8: Detailed karyotype analysis of Chmmolaena d r a b

Short Total am Volume Arm /rD RE F% in pm, PIA

Nature of prirnaly Type length length RL rabo conshidion

in pm in pm

Neatly sub median

Nearly sub median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Median

Median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Neatly median

Nearly median

Nearly median

Nearly sub median

Nearly median

Neatly median

Neatly median

Nearly rnedtan

Nearly median


Karyotype formula




Average chromosome length in vm

T.F. value (%)

Variation coethclent (VC)



Table 9 : Detailed karyolype analysis of Eupaiorium triplinerw,

Total Type length

in pm

arm Arm -- . Volume Nature of orimam length RL rat In pm

0.58 0.04 0.93 0.03 1.07 34.97 0.1642 3.51 Nearly sub median 0.46

0.55 0.04 0.95 0.(12 1.05 34.38 0.2- 2.95 Nearlysubmedian 0.48

0.46 0.04 0.67 0.;0 1.49 29.22 0.0823 3.46 Nearly sub median 0 43

0.54 0.04 0.82 0.10 1.22 45.w 0.0531 3.25 Nearly median

0.58 0.04 0.97 0.~2 1.03 49.20 0.0737 3.98 Nearly median

0.57 0.04 0.95 0.c3 1.05 48.72 0.1647 3.41 Nearly median

0.51 0.04 0.83 0.C9 1.21 45.27 0.1425 3.30 Neally median

0.47 0.04 0.71 0.17 1.41 41.55 0.0931 3.24 Nearly median

0.55 0.04 0.97 0.C1 1.03 49.35 0.0809 3.32 Nearly median

0.52 0.04 0.88 0.C6 1.13 46.91 0.0556 3.73 Nearly median

0.54 0.04 0.99 OC 1 1.01 49.65 0.0808 3.59 Nearly median

0.54 0.04 0.98 0.C1 1.02 49.53 0.0470 3.75 Nearly median

0.53 0.04 0.97 0.01 1.03 49.33 0.0931 3.53 Nearly median

0.41 0.04 0.66 0.20 1.51 39.85 0.0446 3.33 Nearly median

0.45 0.04 0.80 0.11 1.25 44.54 0.0686 3.96 Nearly median

0.49 0.04 0.98 0.01 1.02 49.46 0.0578 3.68 Nearly median

0.49 0.04 0.98 0.01 1.02 49.42 0.0868 3.79 Nearly median

0.48 0.04 0.95 0.03 1.06 48.64 0.0288 3.91 Nearly median

0.48 0.04 0.99 0.01 1.01 49.71 0.0389 3.47 Nearly median

B 0.95 0.45 0.03 0.89 0.16 1.12 47.07 0.0424 4.10 Nearly median

B 094 0.45 0.03 0.94 0.03 1.06 48.46 0.0402 3.63 Nearly median

B 0.90 0.45 0.03 0.97 0.01 1.03 49.31 0.1190 3.20 Nearly median

B 0.90 0.44 0.03 0.97 0.02 1.03 49.21 0.0766 3.52 Nearly median

B 0.89 0.44 0.03 0.98 0.11 1.02 49.42 0.0625 3.24 Nearly median

B 0.66 0.42 0.03 0.93 0.13 1.07 46.28 0.0449 3.93 Nearly median


Karyotype formula

Number of chromosome pairs with secondary constriciion




T.F. value (%)



Total volume of chromosomes in pm3

Table 10 : Detailed karyotype analysis of Mnrania &at3

Total Shoe arm Volume p/A Nature of primary

Type length length RL A" ratlo AD RE F% inpm, constriction in pm in pm

Volume p/A Nature of primary A" AD RE F% inpm, ratlo constriction

Nearly sub median

Nearly sub median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Normal somatic chromosome

Karyotype formula

number

Number of chromosome paws with secondaw mnstritimn


Toial chromosome length in Vm


T.F. value (%)

Variation d c i e n t (VC)



Table 11 : Detailed karyolype analysis of Cor~yza bonariensis

Nearly median

Narrly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly M a n

Median

Nearly median

Nearly median

Nearly median

Nearly median

early mediin

Nearly median

6 1.08 0.52 0.03 0.94 0.03 1.07 48.38 0.0298 3.45 Nearly mediin

6 1.07 0.51 0.03 0.92 0.04 1.08 48.02 0.0333 3.03 Nearly median

6 1.06 0.48 0.03 0.83 0.09 1.21 45.32 0.0986 2.82 Nearly median

6 105 0.50 0.03 0.90 0.05 1.11 47.44 0.0237 3.51 Nearly median

8 1.04 0.46 0.03 0.79 0.11 1.26 44.28 0.0361 3.70 Nearly median

6 0.96 0.47 0.03 0.97 0.01 1.03 49.29 0.1114 3.03 Nearly median

I l b 12b 13b - 14b -

bigs. I 1 b, l le - CO~IJ.;(J canadensis: 1 l b - mitotic metaphasc (2n = 18). I le - mciotic mctaphase (2n = 9); I2b - Dichrocephula chrysanrhetnifolia mitotic metaphase (2n = 18); 13b - Erigeron mucronatus mitotic metaphase (2n = 18); 14b, l4e -Blumeu iacera; 14b - mitotic metaphase (2n = 36), 14e - meiotic metaphase (n = 18); 15b, I Sc, 15e - Blumea mollis: 15b - mitotic metaphase (2n - 18); 15c . somatic variant (2n = I6),15e - meiotic metaphase (n = 9); 16b - Blurnea oxyodonra milotic meraphse (2n : 28); 17b,17c,I 7c1 - Sphaeranrhus indicus: 17b - mitotic metaphase (2n = 201, 17c - somatic variant (2n = 1 X), 17c1 - somatic variant (2n = 16); 18b,l8e - Vicoa indira: 18b - mitotic metaphase (2n - 18), 18e - meiotic rnetaphase (n = 9); 19b - Auanthospermum hispidum mitotic mctaphase (2n = 22).

Bar represents 5prn each


Karyolype formula


Range of chromosome length in Vm

~ o t a l chm- length in pm

Average c h m m m length in pm

T.F. value (%)

Variation mefiicient (VC)



Table 12 : Detailed karyotype analysis of Cmy2a canedensis

Short arm Type length

t e r n RI

inpm in,,",

VOlUrn P,A A? AD RB F% in(rm$ ~a tum of primary

- rabo consbidion


€3 1.05 0.45 0.12 0.73 0.15 1.36 42.31 0.0346 2.85 Neariy median

B 1.04 0.50 0.12 0.95 0.03 1.06 48.64 0.0487 3.13 Nearly median

B 0.98 0.48 0.11 0.97 0.02 1.03 49.22 0.0713 2.85 Nearly median

B 0.95 0.42 0.11 0.80 0.11 1.24 61.58 0.0462 2.93 Nearly median

B 0.92 0.46 0.10 0.98 0.01 1.02 49.50 0.0719 2.99 Nearly median

B 0.68 0.43 0.10 0.98 0.02 1.04 49.00 0.0522 2.95 Nearly median

B 0.84 0.39 0.09 0.86 0.08 1.16 46.21 0.0469 3.23 Nearly median

C 0.77 0.35 0.09 0.81 0.10 1.23 44.87 0.0581 3.42 Nearly median


Karyotype formula

Number of chromosome pairs with secondary constriction :

Range of chmmwome length in pm



T.F. value (YO) Variation coefficient (VC)

Disparity index (0.1)


Table 13 : Detailed karyotype analysis of Dichmphala chrysanthemifola

Short Total arm Arm Volume p,A Nature of primary

Type length length RL ratio AD RB F% in pmS in pm constridion

in pm

Nearly sub median

Nearly median

Nearly median

Nearly median

Nearly median

Neariy median

Neariy median

Nearly median

Nearly median

Normal somatic chmmosome numbel

Kafyotype formula

Number of chromosome pairs with sewndary wnstriction

Range of chromosome length in prn



T.F. value (%)




Table 14 : Detailed karyotype analysis of Efigemn mucmnatus

Short Total arm Volume P,A Nature of primary

Type length length RL :z AD RB F% constriction inpm . In pm


Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearty median

Nonnal somatic chmmosome number

Karyolypa formula

Number of chromosome pairs with sewndary conitridion :


Total chromoMnmt length in pm

Average chromoawmt length in pm

T.F. value (%)

Variation coeffident (VC)



2n = 36 (Fig. 14b)

A4 632

2

2.07 - 0.88

43.88

1.22

42.9

25.86

40.33

1.82

Table 15 : h i l e d karyotyps analysis of B I u m lacera

Short Total arm

T Y P ~ ienpth RL AD RB F% P,A Nature of primary

in pm Fngm in pma w n s m o n In pm

A 2.07 0.88 0.07 0.80 0.11 1.25 31.85 0.1069 2.66 Nearly sub median 0.58

A 1.91 0.59 0.07 0.63 0.23 1.59 31.19 0.0410 2.89 Nearlywbmedian 0.37

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median


Karyotype formula

Number of chromosome pairs with secondary constriction : Range of chromosome length in pm



T.F. value (%)

Variation M c i e n t (VC)

Disparily index (0.1)

Total volume of chromosomes in Mm'

Table 16 : Detailed kalyotype analysis of Bfumea mollis

Short Total arm Arm Volume p,A Nature of primary Type 1- length RL ratio .\D RB FSb in pm, consbidion

in lrm in pm

Nearly medin

Nearly median

Nearly median

Nearly median

Nearly median

Neady median

Nearly median

Nearly median

Nearly median


Karyotype formula

Number of chromosome paws with secondary constriction




T.F. value (%)

Variation coefficient O/C)



Table 17 : Detailed karyolype analysis of Blumea oxyodonla

~~~

Short Total arm Typm length Volume

Arm 4 RB F% in pm3 P/A Nature of primary lensth inpm . RL ratio constriction m pm

A 2.17 0.79 0.13 0.70 (. I8 1.43 36.25 0.0533 1.84 Nearlysubmedien 0.26

Nearly sub median

Nearly sub median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median


Karyotype formula

Number d chromosome pairs with samndary mnstriction



Average chromosome lenglh in pm

T.F. value (%)

Variation d l d e n t PC)


Total volume of chromosomes in vm'

Table 18 : Detailed kary- analysis of !:phaemnfhus indicus

2n = 20 (Fig. 17b)

A4 616

2

1.90 - 0.91 26.16

1.31

42.66

21.04

35.23

1.76

Short Total arm Volume p,A Nature of primary

T W length length RL :E AD RE F% inpmS consiridon in vm in pm

A 1.90 0.69 0.11 0.98 0.01 1.02 36.23 0.1466 2.36 Nearlysubmedian

B 1.42 0.56 0.11 0.65 0.21 1.55 39.25 0.0965 2.54 Nearly median

B 1.37 0.63 0.10 0.85 0.08 1.18 45.98 0.0701 3.00 Nearly median

B 1.30 0.63 0.10 0.93 0.04 1.07 48.23 0.0846 2.93 Nearly median

B 1.25 0.55 0.10 0.78 0.12 1.28 43.77 0.1106 2.63 Needy median

B 1.16 0.51 0.09 0.79 0.12 1.27 44.04 0.1111 3.05 early median

8 1.06 0.48 0.08 0.83 0.09 1.21 45.31 0.0980 2.14 Nearly median

B 1.08 0.52 0.08 0.93 0.04 1.08 48.16 0.0567 2.36 Nearly median

B 0.91 0.45 0.07 0.98 0.01 1.02 49.60 0.0483 2.60 Nearly median


Karyotype formula



Total chrmosmne length in pm

Averaga chromosome length in pm

T.F. value (%)

Variation we f fwn t (VC)



Table 19 : Detailed karyotype analysis of b i m e indica

Short Total arm volume p,A

A? AD RB F% inpm, Nature of primary Type length length RL ratlo wlgbiClion in um in

Nearly sub median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median


Karyolype formula

Number of chmmosome pairs with sewndory constriction




T.F. value (%)

Variation d ~ c i e n t WC)



Table 20 : Detailed karyotype analysis of ,\canUlospermum hispidurn

Short Total arm Volume p,A Nature of primary Type length length RL AD RB F% in pm. combiCtion

in pn In pm




B 1.25 0.59 0.10 0.88 0.06 1.13 46.94 0.0912 2.46 Nearly median

B 1.09 0.52 0.09 0.92 0.04 1.09 47.78 0.0795 2.70 Nearly median

B 0.94 0.43 0.08 0.86 0.08 1.16 46.20 0.0412 3.75 Nearly median

B 0.92 0.46 0.07 0.99 0.01 1.01 49.71 0.0395 2.73 Needy median

B 0.88 0.40 0.07 0.85 0.08 1.18 45.85 0.0387 3.49 Neady median

B 0.85 0.39 0.07 0.83 0.09 1.20 45.39 0.0445 2.90 Nearly median

B 0.81 0.34 0.07 0.71 0.17 1.40 41.58 0.0202 3.78 Nearly median

C 0.72 0.33 0.06 0.85 0.08 1.18 45.90 0.0165 3.78 Nearly median

Figs.20b - Bidens pilosa mitotic metaphase (2n = 72); 2 I b,2 1c,2 l e,2ie1- Cosmos bipinnatus 0. orange: 21b - mitotic metaphase (2n = 241, 2 1c - somatic variant (2n = 22), 21 e - meiotic metaphase (n = 1 I), 2 1 el - meiotic metaphase (n = 12); 22b,22e - Cosmos bipinnah cv. yellow: 22b - mitotic metaphase (2n = 24), 22e - meiotic metaphase (n = 12); 23b - Cosmos caudatw mitotic rnetaphase (2n = 24); 24b,24c,24e - Eclipta prostrata: 24b - mitotic metaphase (2n = 22), 24c - somatic variant (2n = 18), 24e - meiotic metaphase (n = 1 I); 25b - Galinsoga pamiflora mitotic rnetaphase (2n = 32); 26b - Melampodium paiudosm mitotic metaphase (2n = 24); 27b - Parthenium hysrerophorus mitotic metaphse (2n = 36), 28b - Sigesbeckia orientalis mitotic metaphase (2n = 30); 29b - Spilanthes calva mitotic metaphase (2n = 78).

Bar represents 5 p - i each


Karyotype formula





T.F. value (%)


Disparity index (D.1) Total volume of drromosomes in pm'

Table 21 : Detailed kaiyolyp analysis of Bidens piloss

Short Total TYW length length RL krb", AD RB F% PIA Nature of primary

inpm . constridion m pm

A 1.30 0.47 0.03 0.78 0:12 1.28 38.15 0.0671 2.80 Nearly sub median 0.23

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Cosmos bipinnalvr cv. orange


Karyotype formula

Number of chromosome pain with secondary constriction


Total chromwome length in pm


T.F. value (%)

Variation coefficient (VC)S


Total volume of chromosomes in pm3

Table 22 : Detailed kalyotype analysis of Co::mos bipinnafus ccv. m g e

Short Total arm Volume P,A A? AD RB F% inpms Nature of primary

Type length length RL ratto constriction in pm in pm

A 1.63 0.44 0.09 0.58 026 1.72 27.24 0.1191 3.13 Nearly sub median 0.42

B 1.54 0.75 0.12 0.96 002 1.04 48.69 0.0881 3.09 Nearly median

B 1.20 0.48 0.09 0.67 0.20 1.49 40.08 0.0514 3.16 Nearly median

B 1.17 0.52 0.09 0.80 C . l l 1.25 44.47 0.1203 3.11 Nearly median

B 1.14 0.51 0.09 0.81 C . l l 1.24 44.73 0.0563 3.28 Nearly median

B 1.03 0.48 0.08 0.87 C.07 1.15 46.50 0.0237 4.28 Nearly median

B 0.99 0.48 0.08 0.95 C.03 1.06 48.65 0.0516 3.71 Nearly median

B 0.96 0.39 0.07 0.70 I 1.43 41.15 0.1027 3.72 Nearly median

B 0.95 0.49 0.07 1.06 -0.03 0.94 51.46 0.0255 3.67 Median

B 0.89 0.41 0.07 0.85 (1.08 1.18 45.87 0.0390 3.54 Nearly median

B 0.81 0.40 0.06 1.00 (1.00 1.M) 50.01 0.0615 3.72 Median

C 0.76 0.40 0.06 1.11 -tl.05 0.90 52.69 0.0371 3.87 Median

Cosmos blpinnatus cv. ydlow


Karyotype formula

Number of chromosome pairs with secondaly constriction

Range of chrornoaome length in pm


Average chromcsome length in um

T.F. value (%)

Variation M c i e n t (VC)


Total volume of chromosomes in pma

Table 23 : Detailed karyotype analysis of C a s m bipinnatus cv. yellow

Short Total arm volume P,A RL :z ,+D RB F% inurn. Nature of primary

Type length in pm

constriction in pm


A 1.68 0.56 0.06 0.96 C.02 1.04 33.02 0.0804 2.83 Nearly submedian 0.55

A 1.66 0.63 0.08 0.98 C.01 1.02 37.74 0.1091 2.39 Neatly median 0.39

A 1.54 0.53 0.07 0.91 C.05 1.10 34.68 0.0504 2.84 Nearlysubmedian 0.42

B 1.36 0.67 0.09 0.94 C.03 1.06 48.56 0.3049 3.13 Nearly median

B 1.21 0.59 0.08 0.97 C.02 1.03 49.19 0.1054 2.41 Nearly median

B 1.12 0.52 0.07 0.66 (,.07 1.16 46.26 0.1563 2.80 Nearly median

B 0.93 0.46 0.06 0.97 ('.01 1.03 49.33 0.0690 2.60 Nearly median

B 0.62 0.36 0.05 0.77 (1.13 1.30 43.48 0.0436 2.62 Neariy median

C 0.79 0.39 0.05 0.99 (1.00 101 49.84 0.1299 2.56 Nearly median

c 0.72 0.34 0.05 0.91 (1.05 1.10 47.70 0.0192 3.02 Nearly median

C 0.70 0.32 0.05 0.67 (1.07 1.15 46.56 0.0237 3.26 Nearly median

Casmos caudatus


Karyotyp formula





T.F. value (%) Variation coefidant (VC)



Table 24 : Detailed karyotype analysis of Cosmos caudatus

Short Total am RL tz 4D RB F% PIA

Nature of primary T Y P ~ length l.ngm in pms constribion

in vm in pm

A 1.49 0.56 0.11 0.79 0.12 1.26 37.36 0.0011 2.83 Neariysub median 0.23

B 1.19 0.50 0.10 0.73 1.16 1.38 42.08 0.0362 2.84 Nearly median

B 1.07 0.51 0.09 0.89 1.06 1.12 47.16 0.0462 3.21 Nearly median

B 1.06 0.47 0.09 0.81 3.10 1.23 44.81 0.0326 2.64 Nearly median

B 1.00 0.44 0.08 0.77 3.13 1.31 43.38 0.0193 3.50 Nearly median

B 0.97 0.44 0.08 0.82 010 1.22 45.09 0.0197 2.89 Nearly median

B 0.95 0.44 0.08 0.86 0.07 1.16 46.31 0.0519 317 Nearly median

B 0.90 0.33 0.08 0.57 0.27 1.75 36.31 0.0265 3.59 Nearlysubmedian

B 0.88 0.42 0.07 0.93 0.03 1.07 48.29 0.0191 3.38 Nearly median

B 0.84 0.35 0.07 0.72 0.16 1.39 41.77 0.0323 4.22 Nearly median

C 0.79 0.38 0.07 0.92 0.04 1.08 48.03 0.0261 2.93 Nearly median

C 0.76 0.36 0.06 0.90 0.05 1.11 47.42 0.0274 3.64 Neafly median


Karyolype formula

Number of ch ro rnom pairs with secondary constriction :



Average chromosome length in prn

T.F. value (%)

Variation UwIKIcient (VC)


Total volume of chromoswnes in pm'

2n = 22 (Fig. 24b)

A6 84 C12

3

1.63 - 0.61

20.11

0.91

42.11

35.91

45.53

0.60

Table 25 : Detailed karyotype analysis of Edipta prostrata

Short Total arm Volume p,A Type length RL :z AD RB F% inurn, Nature of primary

in pm constriction in pm

A 1.63 0.57 0.13 0.75 0.14 1.33 35.20 0.0385 3.15 Nearly submedian 0.29



B 1.03 0.48 0.10 0.69 0.06 1.13 46.99 0.0637 3.05 Nearly median

B 0.87 0.42 0.09 0.94 0.03 1.06 48.54 0.0318 3.48 Nearly median

C 0.78 0.37 0.08 0.92 0.04 1.09 47.78 0.0212 3.40 Nearly median

C 0.66 0.33 0.07 0.95 0.03 1.06 48.59 0.0139 3.69 Nearly median

C 0.67 0.33 0.07 0.95 0.03 1.05 48.70 0.0306 3.73 Nearly median

C 0.63 0.30 0.06 0.91 0.05 1.10 47.64 0.0212 3.65 Nearly median

C 0.62 0.31 0.06 0.99 0.01 1.01 49.65 0.0109 3.87 Nearly median

C 0.61 0.29 0.06 0.92 0.04 1.09 47.86 0.0153 3.72 Nearly median


Kayotype formula

Number of chmmosome pairs with secondan, constriction

Range of chromosome length in vm

Total chromosome langth in vm


T.F. value (%)




2n = 32 (Fig. 25b)

A4 016 C12

2

1.34 - 0.68

28.62

0.95

44.16

19.95

32.67

1.26

Table 26 : Detalied karyotype analysis of Gali~~soga pamr7m

Short Total am Type length length Volume p,A Nature of primary RL All RB FX in vm,

in lrm in vm constriction

A 1.27 0.38 0.06 0.73 0.11; 1.37 30.22 0.0861 2.78 Nearlysubmedkn 0.36

B 1.07 0.52 0.08 0.95 0.0:l 1.06 48.64 0.0707 3.23 Nearly median

B 0.95 0.46 0.07 0.97 0.0; 1.04 49.13 0.0332 3.04 Nearly median

B 0.94 0.43 0.07 0.84 0.05 1 19 45.71 0.0454 2.98 Nearly median

B 0.90 0.44 0.06 0.94 0.03 1.08 48.57 0.0267 3.42 Nearly median

B 0.87 0.37 0.06 0.74 0.15 1.36 42.37 0.0463 3.32 Nearly median

B 0.63 0.37 0.06 0.79 0.12 1.27 44.15 0.0240 2.91 Nearly median

B 0.82 0.38 0.06 0.88 0.06 1.14 46.78 0.0775 2.83 Nearly median

B 0.80 0.40 0.06 0.97 0.02 1.03 49.23 0.0156 3.21 Nearly median

C 0.79 0.39 0.06 0.96 0.02 1.04 46.92 0.0226 3.20 Nearly median

C 0.79 0.35 0.06 0.78 0.12 1.28 43.89 0.0314 3.28 Nearly median

C 0.76 0.39 0.05 0.96 0.01 1.02 49.40 0.0209 3.22 Nearly median

C 0.76 0.37 0.05 0.98 0.01 1.03 49.38 0.0308 2.77 Nearly median

C 0.72 0.32 0.05 0.80 0.11 1.24 44.58 0.019i 3.18 Nearly median

C 0.68 0.31 0.05 0.85 0.08 1.17 46.08 0.0141 3.44 Nearly median

Normal somatic chmmcwwne number

Keryotype formula


Range of chromosome length in !nn



T.F. value (%)



Total volume of ch rommes in pm'

Table 27 : Detailed karyotype analysis of Melitmpadium paludosm

Shalt Total Volume P,A A? AD RE F% inma

Nature of primary Tw length length RL ratlo mnstriction

in vm in pm

Neatly median

Nearly medin

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median


Karyotype formula



Total chromosome length in prn


T.F. value (%)

Variation coeffiuent (VC)



Table 28 : Detailed karyotyp analysis of Panhenium hystemphms

2n = 36 (Fig. 27b)

A2 820 C14

lorn' arm Volume plA Nature of primary Type lenga RL tr AD RE F% constridion

in pm in ,,m

Short Total arm Volume plA Nature of primary

Type lenga RL tr AD RE F% constridion in pm in pm


Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median


Kacyoiype formula

Number of chromosome pairs wiih secondaN constriction




T.F. value (%)

Variation wefficient (VC)


Total volume of chromosomes in prn'

2n = 30 (Fig. 28b)

A2 84 C24

1

1.24 - 0.61

23

0.76

46.9

19.27

34.05

0.74

Table 29 : Detailed karyotype analysis of Si{~esbeckia orientalis

Short Total an Arm 4D RE F% PIA Nature of primary

Type lenm length RL ratto wnstriction in pm in irm

Nearly sub medain

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Median

Nearly median

Nearly median

Nearly median

Nonal somatic chromosome

Karyotype formula

number


Range of chromosome kngth in pm

Total chromosome knglh in pm


T.F. value (%)

Variation coefftcient CJC)


Total volume of chromosomes in urna

Table 30 : Detailed karyotype analysis of Spilanlhes calva

Short Total an

Volume P,A Nature of primary Type length length RL ZO AD RB F% inpm,

in pm constriction in pm

0.14

0.06

0: 3

0:4

0.(11

0.03

OC'O

0.C 1

0.02

0.00

0.1 1

0.02

0.0'3

0.1 1

0.01

0.01

0.20

o.l:! 0.01

0.0''

0.1'1

Nearly sub median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly medin

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Neady median

Nearly median

Nearly median

Nearly mediin

Nearly median

Nearly median

Nearly median

Nearly median

bigs. 3Ub - Spilanrhes ciliaru i-nitotic metaphase (2n = 52); 3 1 b - Spilnnrhes radicans mitotic metaphase (2n = 78); 32b - Spilanrhes uliginosa mitotic metaphase (2n = 52); 33b - Synedrella nodgora mitotic metaphase (2n - 40); 34b - Tithonia diversifolia mitotic metaphase (2n = 34); 35b,35e - Tridax procumbens: 35b - mitotic metaphase (2n = 36), 35e - meiotic tnetaphase (n = 18); 36b - Wedelia chinensis mitotic metaphase (2n =50); 37b - Wedelia irilobata mitotic metaphase (2n = 50); 38b - Zinnia ele'qans mitotic rnetaphase (2n = 24); 39b ,39c - Tagetes erecta cv. orange: 39b - mitotic metaphase (2n - 48), 39c - somatic variant (2n = 24).

Rar represents 5pm each


Kafyotype formula

Number of chromosome pairs with secondarr constriction




T.F. value (%)




Table 31 : Detailed karyotype analysis of Spilanthes cifiata

Short Total arm Volume P,A Nalure of primary

T Y P ~ length length RL A" ratlo AD RB F% inpm, constriction in pm in vm

A 1.12 0.32 0.04 0.64 0.22 1.57 28.21 0.0347 2.57 Nearly submedian 0.31



Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Median

Nearly median

Nearly median

Nearly sub median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Neady median

Nearly median

C 0.65 0.30 0.03 0.87 0.07 1.15 46.42 0.0147 3.69 Nearly median

c 0.63 0.28 0.03 0.83 0.09 1.21 45.28 0.0207 3.40 Nearly median

C 0.59 0.28 0.03 0.92 0.04 1.08 48.01 0.0102 3.77 Nearly mediin

C 0.58 0.29 0.03 0.97 0.02 1.04 49.12 0.0159 3.04 Nearly median

C 0.56 0.28 0.03 0.97 0.01 1.03 49.31 0.0096 3.33 Nearly median

C 0.53 0.25 0.03 0.85 0.08 1.18 45.90 0.0203 3.73 Nearly median

C 0.50 0.24 0.03 0.88 0.06 1.14 46.79 0.0104 3.41 Nearly median

Spilanihes radicans


Karyotype formula

Number of chromosome pairs with secondary conshiction




T.F. value (%)




Table 32 : Detailed kalyotype analysis of Sprlanthes radicans

Short Total an Type length RL :z /iD RE F% Volume P/A Nature of primary

in pm length in pm' constriction in pm

A 1.62 0.61 0.04 0.97 001 1.03 37.56 0.0323 3.26 Nearly median 0.39

A 1.54 0.50 0.03 0.86 0 07 1.16 32.69 0.0396 3.20 Nearly sub median 0.45

A 1.46 0.46 0.03 0.77 013 1.30 31.82 0.0242 3.06 Nearlysubmedian 0.39

B 1.34 0.58 0.04 0.75 014 1.33 42.95 0.0288 3.66 Nearly median

B 1.05 0.44 0.03 0.71 0 17 1.41 41.48 0.2766 3.56 Nearly median

B 1.03 0.44 0.03 0.76 014 1.32 43.05 0.0277 3.18 Nearly median

B 0.92 0.41 0.03 0.81 0 10 1.23 44.79 0.0305 2.82 Nearly median

B 0.84 0.37 0.03 0.78 012 1.28 43.89 0.0248 3.14 Nearly median

B 0.84 0.41 0.03 0.98 001 1.02 49.43 0.0366 3.41 Nearly median

B 0.83 0.37 0.03 0.79 012 1.27 44.09 0.0196 3.45 Nearly median

B 0.81 0.29 0.03 0.56 0 28 1.79 35.86 0.0245 3.71 Nearly sub median

C 0.80 0.37 0.03 0.85 008 1.18 45.94 0.0175 3.40 Nearly median

C 0.79 0.33 0.03 0.72 016 1.39 41.87 0.0207 3.34 Nearly median

C 0.77 0.39 0.02 1.01 -0.01 0.99 50.31 0.0109 3.32 Nearly median

c 0.75 0.36 0.02 0.92 004 1.09 47.88 0.0156 3.42 Nearly median

C 0.74 0.36 0.02 0.95 002 1.05 48.75 0.0251 3.40 Nearly median

C 0.74 0.35 0.02 0.91 005 110 47.55 0.0381 3.53 Nearly median

c 0.73 0.36 0.02 0.98 001 1.02 49.51 0.0085 3.54 Nearly median

C 0.72 0.32 0.02 0.81 0 11 1.24 44.74 0.0077 3.94 Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly medtan

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly sub median

Nearly sub median


Karyotype formula

Number of chromosome pairs with secondar) constriction

Range of chromosome iength in pm



T.F. value (%)

Variation weffment (VC)


Total volume of chromosomes in um3

Table 33: Detailed karyotype analysis of Spilanfhes uliginosa

Total Type length

In pm

arm length

Arm AD RE RL ratio

2n = 52 (Fg. 32b)

A4 834 C14

2

1.25-061

47.75

0.918

45.92

17.73

34.4

2.13

Volume p,A Nature of primary F% in pm= constriction

Nearly sub median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearty median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

C 0.79 0.37 0.03 0.91 O.O!j 1.10 47.51 0.0372 2.79 Nearly median

C 0.78 0.38 0.03 0.94 0.03 1.06 48.51 0.0384 2.77 Nearly median

C 0.77 0.34 0.03 0.81 0.11 1.24 44.63 0.0101 3.25 Nearly median

C 0.76 0.36 0.03 0.92 0.04 1.09 47.86 0.0231 2.80 Nearly median

C 0.70 0.30 0.03 0.76 0.14 1.32 43.12 0.0394 2.88 Nearly median

C 0.61 0.28 0.03 0.85 0.08 1.18 45.90 0.0531 3.06 Nearly median


Karyotype formula

Number of chromosome pain with sewndaty mnstriction



Average chromcsome length in pm

T.F. value (%)



Total volume of chromosomes in uma

Table 34 : Detailed karyotype analysis of Synedrella nodifbra

2n = 40 (Fig. 33b)

A4 616 C20

2

1.67 - 0.57

35.32

0.883

42.24

34.58

40.86

1.65

Shoa Total arm Volume p,A Nature of primary Type length RL tE RB F% in pm.

inpm . wnstriction In vm

Nearly sub median

Nearly sub median

Nearly sub median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly sub median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly medin

marly median

Nearly median

Nearly median

Nearly median

Nearly median


Karyotype formula

Number of chromosome pairs with secondary c3nstriction

Range of chmmosome length in vm


Average chromosome length in Vm

T.F. value (%)

Variation meffident (VC)

Dispariky index (D.1)


Table 35 : Detailed karyotype analysis of TiUm~ria d i~~mYdia

Short Total am A m AD F% Volume P,A Nature of primary Type length length RL ratio in pma

in vm in vm constriction

A 1.79 0.55 0.07 0.65 0.2:! 1.55 30.74 0.1271 2.66 Nearlysubmedian 0.39


B 1.66 0.76 0.08 0.90 O.O!i 1.12 47.27 0.0680 2.71 Nearly median

B 1.40 0.67 0.07 0.91 O.O!i 1.09 47.74 0.0444 3.07 Nearly median

B 1.31 0.50 0.07 0.62 0.2:1 1.61 38.30 0.0434 3.26 Nearly median

B 1.16 0.50 0.06 0.76 O.lr. 1.32 43.18 0.1491 2.67 Nearly median

B 1.12 0.53 0.06 0.90 O.O!, 111 47.29 0.0506 2.77 Nearly median

B 1.08 0.54 0.06 0.99 0.0(1 1.01 49.87 0.0373 3.70 Nearly median

B 1.05 0.50 0.05 0.93 0 108 48.07 0.0143 2.99 Nearly median

B 1.02 0.45 0.05 0.79 0.1; 1.26 44.21 0.0362 2.91 Nearly median

B 0.99 0.44 0.05 0.80 0.1' 1.25 44.46 0.0676 2.64 Nearly median

B 0.98 0.44 0.05 0.83 O.l i1 1.21 45.24 0.0195 3.43 Nearly median

B 0.96 0.47 0.05 0.97 0.0;' 1.03 49.22 0.0127 3.53 Nearly median

B 0.94 0.43 0.05 0.84 0.OIi 1.20 45.54 0.0468 2.67 Nearly median

B 0.87 0.40 0.04 0.67 O.Oi 1.14 46.62 0.0271 3.23 Nearly median

C 0.80 0.38 O M 0.93 0 1.08 48.09 0.0170 3.61 Nearly median

C 0.73 0.35 0.04 0.92 0 . 1.09 47.86 0.0072 2.36 Nearly median


Karyotype formula

Number of chromosome pain with secondary a)nstrlction




T.F. value (%)

Variation coe f f t n t (VC)


Total volume of chromosomes in um'

Table 36 : Detailed karyotype analysis of Trida): procumbens

2n = 36 (Fig. 35b)

A6 830

3

2.23 - 1.25

58.14

1.615

40.9

15.38

28.16

4.5402

Short Total arm Volume p,A RL AD RB F% inpm, Nature of primary Type length length

in pm mnsMdion In pm

A 2.23 0.71 0.12 0.64 0.2:! 1.55 31.61 0.1344 2.64 Nearlysubmedian 0.43

A 1.96 0.63 0.09 0.88 O.Mi 1.14 31.96 0.0587 2.25 Nearlysubmedian 0.62

A 1.94 0.62 0.09 0.88 0.0:' 1.14 32.20 0.1748 3.02 Nearly sub mediin 0.60

B 1.79 0.75 0.12 0.73 0.lli 1.38 42.05 0.0375 2.65 Nearly median

B 1.76 0.69 0.12 0.66 0.2' 1.53 39.59 0.0692 2.47 Nearly median

B 1.70 ' 0.84 0.12 0.97 0.0'1 1.03 49.35 0.2553 2.41 Nearly median

B 1.67 0.75 0.11 0.82 0.10 1.21 45.17 0.0737 2.62 Nearly median

B 1.64 0.70 0.11 0.74 I ! 1.36 42.43 0.1250 2.96 Nearly median

B 1.62 0.75 0.11 0.86 0.0" 1.16 46.28 0.1046 2.99 Nearly median

B 1.54 0.67 0.11 0.78 I ! 1.28 43.86 0.0923 2.73 Nearly median

B 1.50 0.68 0.10 0.84 0.0!1 1.19 45.69 0.1111 2.67 Nearly median

B 1.49 0.56 0.10 0.60 O.Z!i 1.68 37.36 0.0023 2.42 Nearlysubmedian

B 1.45 0.68 0.10 0.88 0.0" 1.14 46.74 0.3176 3.43 Nearly median

B 1.44 0.52 0.10 0.56 0.2;3 1.79 35.81 0.0677 2.97 Nearlysubmedian

B 1.39 0.56 0.10 0.68 0.13 1.46 40.60 0.2996 3.54 Nearly median

B 1.38 0.59 0.09 0.74 0.15 1.36 42.42 0.1699 2.90 Nearly median

B 1.31 0.58 0.09 0.79 0.lZ 1.26 44.15 0.1015 3.57 Nearly median

B 1.25 0.61 0.09 0.94 0.03 1.06 48.49 0.0752 3.03 Nearly median


Karyotype formula

Number of chromosome pairs with sewndar) constriction : Range of chromosome length in pm



T.F. value (%)




2n = 50 (Fig. 36b)

A4 68 C38

2

1.01 - 0.48

35.81

0.716

44.84

18.68

35.57

1.41

Table 37 Deta~led karyoh/pe analysis of Wedt,lia chinensis

Short Total arm

Arm Type length length Volume P,A Nature of primary

RL AD RB F% in pm'

in pm in pm constriction

A 1 01 0 33 0.04 0.85 0.06 118 32.22 0.0680 3.45 Nearly submedian 0 30


Nearly median

Median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Median

Median

Nearly median

Median

Nearly mediin

Nearly sub median

Nearly median

Median

Nearly median

C 0.60 0.22 0.03 0.58 0 26 1.72 36.79 0.0468 3.67 Nearly sub median

C 0.59 0.31 0.03 1.12 -13.06 0.89 52.88 0.0115 4.08 Median

C 0.57 0.27 0.03 0.90 005 1.11 47.45 0.0090 4.34 Nearly median

C 0.53 0.27 0.03 0.99 000 1.01 49.86 0.0062 4.35 Nearly median

C 0.48 0.21 0.03 0.76 0.14 1.32 43.10 0.0136 3.69 Nearly median


Karyotype formula





T.F value (76)




2n = 50 (Fig. 37b)

A4 B2 C44

2

1.15-0.41

30.78

0.61

43.14

25.38

47.43

0.89

Table 38 Deta~led karyotype analysls Wede ra tnlobata

Short Total arm

Volume p,A A? PD RE F% in pm, Nature of primary

Type length length In pm

RL ratlo constriction In pm

Nearly sub median

Nearly sub median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly sub median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

C 0.51 0.19 0.03 0.59 0.:'6 1.69 37.17 0.0126 4.56 Nearly sub median

C 0.49 0.20 0.03 0.67 O.:M 1.50 40.07 0.0160 4.50 Nearly median

c 0.49 0.22 0.03 0.81 0. 11 1.24 44.71 0.0160 4.03 Nearly median

C 0.47 0.21 0.03 0.79 012 1.27 44.00 0.0131 4.44 Nearly median

C 0.41 0.17 0.03 0.68 0.19 1.48 40.40 0.0116 4.45 Nearly median

Normal somatic chromosome numbel

Kafyotype formula

Number of chromosome pairs with seconda~y constriction




T.F. value (%)

Variation memuen1 (VC)



Table 39 : Detailed kafyotype analysis of Zinnia elegans

Short Total arm Arm Volume p,A Nature of primafy

Type length length RL ratio 4D RB F% in pm, inpm . constriction

In pm

Nearly sub median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median


Karyotype formula Number of chromosome pairs with secondary iXJnStricti0n :

Range of chrommme length in vm



T.F. value (%)


Disparity index (D.1) Total volume of chmmosomes in pm'

Table 40 : Detailed karyotype analysis of Tagetas emcta cv orange

Short Total arm ~ r m Volume plA Nalure of primary

Type length length RL ratio 4D RB F% mnstridion in vm in vm

Nearly median

Nearly sub median

Nearly median

Nearly sub median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Median

Nearly median

Nearly median

Median

Nearly median

Nearly median

Nearly median

Nearly sub median

Nearly median

Nearly median

C 0.76 0.30 0.03 0.66 C.21 1.53 39.60 0.0072 4.43 Nearly median

C 0.75 0.36 0.03 1.03 4.02 0.97 50.62 0.0099 4.29 Median

C 0.67 0.30 0.03 0.82 010 1.22 45.02 0.0101 4.76 Nearly median

C 0.60 0.21 0.03 0.52 0 31 1.92 34.26 0.0078 4.78 Nearlysub median

Figs. 40b - Tagures erecla cv pale yellow mitotic mclapha5e (211 = 48); 4lb,J lc.4 lcl - Tageles erecra cv. yellow: 4 1 b - mitotic m e t a p h a e (2n = 24), 4 1 c - somatic variant (2n = 22), 41c1 - somatic variant (2n = 18); 42b - Tagetes paflda mitotic metaphase (2n = 24); 43b - Chrysanthemun~ parrheniurn mitotic metaphasc (2n = 18); 44b - Crassocephalum crepidiodes mitotic metaphase (2n = 40); 45b.45e - Emilia sonchijblia: 45b - mitotic metaphase (2n -- lo), 45e - meiotic metaphase (n = 51, 46b,46e ~Vofonia grandflora : 46b - mitotic metaphase (2n = 20), 46e - meiotic metaphase (n = 10); 47b - Sonchm oleraceus mitotic melaphase (2n = 1 8)

Rar represents 5pm each


Karyolype formula



~ o t a l chromosome length in pm


T.F. value (Ye) Variation coefiicient (VC)



2n = 48 (Fig. 40b)

A4 636 C8

2

1.72- 0.72

48.27

1.01

43.27

22.82

40.74

3.62

Table 41 : Detailed karyotype analysis of Tiwtes emfa cvpc~le yellow

Short Total arm Volume p,A Nature of primary

Type length length

RL AD RB F?6 in pm, constridbn in in prn

~edr ly sub median

Nearly sub median

Nearty sub median

N~arly median

NMrly median

NIarly median

Nsdrly median

N6drly median

Nearly sub m i a n

Nearly median

Nearly median

Nearly median

Nearly medlan

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

C 0.80 0.37 0.03 0.85 0.08 1.17 46.M) 0.0637 2.79 Nearly median

C 0.76 0.37 0.03 0.95 0.13 1.05 48.75 0.0431 2.77 Nearly median

C 0.74 0.33 0.03 0.78 0.12 1.27 43.97 0.0316 3.03 Nearly median

C 0.72 0.32 0.03 0.79 012 1.27 44.06 0.0597 3.23 Nearly median

Tagetes ereeta cv yellow


Karyotype formula



Total chromosome length in Mm


T.F. value (%)


Disparity index @.I)


2n = 24 (Fig. 41b)

A2 08 C14

1

1.20 - 0.67 19.51

0.81

44.38

18.1

28.34

0.4

Table 42 : Detailed karyotype analysis of Tagetes emta cv yelbw

Short Total arm Volume p,A Nature of primary TYW length length RL :G AD RB F% invm, wnsbiction

in vm in


Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median


Karyotyp formula





T.F. value (Oh)

Variation mefficient (VC)



2n = 24 (Fig. 42b)

A2 812 C10

1

1.36 - 0.66

21.01

0.87

45.12

23.92

34.65

0.43

Table 43 : Detailed karyotype analysis of Taqetes pafula

Short Total arm Volume .1D RB F% P,A Nature of primary

Type length inpm . RL ratlo constriction

In urn

A 1.36 0.46 0.10 0.72 (1.16 1.38 33.71 0.0013 2.87 Nearlysubmedian 0.27

B 1.16 0.55 0.11 0.91 0.05 1.10 47.59 0.0663 2.81 Nearly median

B 1.10 0.55 0.10 1.00 0.00 1.00 49.90 0.0290 2.76 Nearly median

B 0.86 0.42 0.08 0.95 11.03 1.06 48.66 0.0153 3.35 Nearly median

B 0.83 0.39 0.08 0.87 0.07 1.15 46.58 0.0188 3.20 Nearly median

B 0.81 0.38 0.08 0.88 0.06 1.14 46.81 0.0170 3.03 Nearly median

B 0.80 0.32 0.08 0.68 0.19 1.48 40.33 0.0089 3.81 Nearly median

C 0.77 0.39 0.07 1.00 1.00 1.00 49.93 0.0195 4.00 Nearly median

C 0.74 0.34 0.07 0.85 1.08 1.18 45.80 0.0140 3.60 Nearly median

C 0.71 0.31 0.07 0.77 1.13 1.30 43.49 0.0092 3.55 Nearly median

C 0.69 0.33 0.07 0.95 1.02 1.05 48.80 0.0101 4.19 Needy median

C 0.66 0.30 0.06 0.83 2.09 1.20 45.45 0.0090 3.83 Nearly median


Karyotype formula

Number of chromosome pairs with samndary omstridion :




T.F. value (%)




2n = 18 (Fig. 43b)

A2 814 C2

1

Table 44 : Detailed karyotype analysis of Chrysanthemum parthenium

Short Total arm ~ r m Volume p,A AD RB F% in pm, Nature of primaty

Type length length in pm RL ratio constriction

in pm

Nearly sub median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Naarty median

Nearly median


Karyotyp formula

Number of chromosome pairs with semndary c,>nstriction




T.F. value (%)

Variation coefficient (VC) Disparity index (D.1)


Table 45 : Detailed karyotyp analysis of Crassooephalum mpidioides

Short Total an RL AD RB F% ' PIA Nature of primary Type length length

in pm in mnstriction



Nearly sub median

Nearly median

Nearly median

Median

Nearly median

Nearly median

Median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Nearly median

Median

Nearly median

Emllla sonchHorIa


Karyotype formula

Number of chmmosome pairs with m n d a r y mstriction



Average chmmosome length in pm

T.F. value (Om)



Total volume of chromosomes in pma

2n = 10 (Fig. 45b)

A2 68 1

2.54 - 1.76 20.25

2.03

43.9

13.49

18.13

4.57

Table 46 : Detailed karyolype analysis of Emila sonchifdia

Short Total arm ~ r m Volume P,A A[) RB F% in Nature of primary

Type length length RL ratio constridion in vm in pm

A 2.54 0.93 0.19 0.95 0.C3 1.06 36.46 0.8783 2.12 Nearlysubmedian 0.63


B 1.97 0.91 0.19 0.85 0.08 1.18 45.93 0.2998 2.05 Nearly median

B 1.83 0.95 0.18 1.09 -O.(kl 0.92 52.17 0.2958 2.42 Nearly median

B 1.76 091 0.17 1.07 -0.M 0.93 51.77 0.3220 2.39 Nearly median


Karyolype formula

Number Of chromosome pairs with secondary constrict~on


Total chrcinwonre length in pm


T.F. value (%)




2n = 20 (Fig. 46b)

A2 B18

1

2.18- 1.26

32.55

1.62

45.46

20.2

25.71

4.5

Table 47 : Detailed karyotype analysis of Notonia grandiflorn

Short Total arm Type length RL tz A l l RB FK PIA Nature of primary

in pm wnswcuon in pm

A 2.16 0.74 0.11 1.37 4 . "6 0.73 46.75 0.1822 2.55 Nearly median 0.42

B 2.17 0.98 0.13 0.83 0.10 2.21 45.23 0.2573 2.81 Nearly median


B 1.80 0.88 0.11 0.96 0.02 1.04 48.93 0.4926 2.67 Nearly median

B 1.62 0.76 0.10 0.88 0.05 1.14 46.80 0.1667 2.54 Nearly median

B 1.51 0.79 0.09 1.11 -0.05 0.90 52.61 0.0612 2.56 Median

B 1.36 0.66 0.08 0.94 0.0:) 1.06 46.52 0.2240 2.51 Nearly median

B 1.34 0.63 0.08 0.89 O.@i 1.12 47.17 0.1261 2.73 Nearly median

B 1.27 0.50 0.08 0.65 0.2:! 1.55 39.24 0.1009 2.95 Nearly median

B 1.26 0.61 0.08 0.93 0.04 1.07 48.21 0.2841 2.62 Nearly median

Sonchus olencws


Karyotype formula


Range of chromosome length in prn



T.F. value (%)



Total volume of chromosomes in urnS

Table 48 : Detailed karyolype analysis of Sonchus oleraceus

2n = 18 (Fig. 47b)

A2 814 C2

Short Total arm Volume

RL :E Al l RB F% in P/A Nature of primary ~ y p e length ,engch

in vrn constriction

In urn

A 1.36 0.50 0.13 0.89 0.[16 1.12 36.68 0.0150 2.84 Nearlysubmedian 0.30

B 1.05 0.52 0.12 0.98 0.C1 1.02 49.51 0.0225 3.37 Nearly median

B 0.96 0.42 0.11 0.77 0.13 1.30 43.56 0.0222 2.76 Nearly median

B 0.91 0.39 0.11 0.74 0.15 1.35 42.51 0.0151 3.50 Nearly median

B 0.69 0.43 0.11 0.93 0.03 1.07 48.28 0.0185 3.38 Nearly median

B 0.85 0.42 0.10 0.98 0.01 1.02 49.60 0.0173 3.73 Nearly median

B 0.83 0.41 0.10 0.96 O.O.! 1.04 49.08 0.0155 3.31 Nearly median

B 0.81 0.35 0.10 0.77 0 . 1 1.29 43.61 0.0188 3.72 Nearly median

C 0.79 0.36 0.09 0.83 0.0!1 1.20 45.35 0.0216 3.60 Nearly median

A B B B C C C C C C C

A A B B B B B B C

A B B B B B B B B B E B B B B B B C C C

Fig. Id to 5d -Comparative idiogram chart of various taxa studied

I d - Elephantopus scaber (2n = 22) 2d - PhV,Iocephalum rangacharii (2n = 18) 3d - Vernonia cinema (2n = 18) 4d - Adenostemma lavenia (2n = 20) 5d - Ageratum mnyzoides r2n = 40)

A A A B B B B B B B B B B B B B B B B B B B B B B

A A B B C C C C C C C C C C C C C C

10d I

A B B B B B B B B B B B l > B B B B B B B B B B B B B B

Fig. 6d to 10d - Comparative idiogram chart of various taxa studied

6d - Agemtum haustonianum (2n = 40) 74 - Chromolaena odomta (Zn = 60) ad - Eupatorium triplinewe (2n = 50) 9d - Mik~nia cordata (2n = 36) 10d - Conyza bonariensis (2n = 54)

l l d I

A B B B B B B B C

A B B B B B B B C

A B B B B B B B B

Fig.1 ld to 15d - Comparative idiograrn chart of various taxa studied

I l d - Conyza canadensis (2n = 18) 126 - Dichrocephala chrysanthemifolia (2n = 18) 136 - Erigeron mut:ronatus (2n = 18) 14d - Blumea lacem (2n = 36) 156 - Blumea mollis (2n = 18)

I

A B B B B B B B B B B C C C

A A B B B B B B B B B B B B B B B B B B B B B B B C C C C C C C C C C C


16d - Blumea oxyodonta (2n = 28) 17d - Sphaeranthus indicus (217 = 20) 18d - Vicoa indica (2n = 13) 19d - Acanthospermum hispidum (Zn = 22) 20d - Bidens pilosa (2n = 52)

A A B B B B B B B B C C C C C C

Fig. 21d to 25d -Comparative idiogram chart of various taxa studied

21d - Cosmos bipinnatus cv orange (2n = 24) 22d - Cosmos bipinnatus cv yellow (2n = 24) 236 - Cosmos caudatus (2r = 24) 24d - Edipta prostrata (2n = 22) 25d - Galinsoga parviflom (2n = 32)

A B C C C C C C C C C C

A B B B B B B B B B B C C C C C C C

A B B C C C C C C C C C C C C

A A A B B B B B B C C C C C C C C C C C C C C C C C

Fig. 26d to 306 - Comparative idiogram chart of various taxa studied

26d - Melampodium paludom (2n = 24) 276 - Parfhenium hystemphorc~s (2n 36) 286 - Sigesbeckia orientalis (2n = 30) 29d - Spilanthes calva (2n = 78) 306 - Spilanthes ciliata (217 = 5.2)

A A A B B B B B B B B C C C C C C C C C C C C C C C C C C C C C C C C C C C C

A A B B B B B B B B B B B B B B B B B C C C C C C C

A A B B B B B B B B C C C C C C C C C C


31d - Spilanthes rndicans (;!n = 78) 32d - Spilanthes ul@inosa (2n = 52) 336 - Synedrella nodiflorn (:!n 40) 1 346 - Tithonia diversifolia (2n = 34) 35d - Tridax procumbens (2n 36) scale 1 pm

A A B C C C C C C C C C C C C C C C C C C C C C C

A B B B B B B B B B B C


36d - Wedelia chinensis (2n = 50) 37d - Wedelia trilobata (2n = 50) 384 - Zinnia elegans (2n = 24) 396 - Tagetes erecta cv orange (2n = 48) 40d - Tagetes erecta cv pale yellow (2n = 48)

A B B B B C C C C C C C

A B B B B B B C C C C C

A B B B B B B B C

A A A B B B B B B B B B B B B B B B B C


41 d - Tagetes e m t a cv yellouc (2n = 24) 42d - Tagetes patula (2n = 24 4

436 - Chrysanthemum parthenium (2n = 18) 44d - Crassocephalum crepidioides (217 = 40)

A B B B B B B B B B

i 1 m . . I . . 1 1 1 1 1 3 . 1 . A B B B B B B B C


45d - Emilia sonchifolia (2n = 10) 46d - Notonia grandiflora (2n = 20) 47d - Sonchus oleraceus (211 = 18)

scale I prn

Table : 49.

Summary of the Karyomorphometerial analysis on the forty seven taxa investigated

No Name of the taxa 2n PL KF CP RCL ACL TCL CLH DI VC TF Volume

Elephantopus scaber 22 2x

nl-..lJ---..h"r,,w ""w*",-h"rii A ,,I..V.,lZ,.-...... . -... o- - 18 2x

Vemnia cinerea 18 2x

Adenostemma lavenia 20 4x

Ageratum conyoides 40 4x

Ageratum haustonianum 40 4x

Chromolaem odorata 60 6x

Eupatorium triplinewe 50 5x

Mikania cordata 36 2x

Conyza bonariensis

Conyza canadensis

Dichrocephala chrysanthemifolia

Erigeron mucronatus

Blumea lacera

Blumea mollis

QI.,,"" ",,"do,tn " . -., . - - - . ., - - -

Sphaeranthus indicus

Vicoa indica

Acanthospennum hispidum

Bidem pilosa

Cosmos hipinnatus cv orange

Cosmos hipinnatus cv yellow

Cosmos caudatus

Eclipta prostrata

Galinsoga parvijlora

Melampodium paludosm

Parthenium hysterophorus

Sigesbeckia orientalis

Spilanthes calva

Spilanthes ciliata

Spilanthes radicans

Spilanrhes uliginosa

SynedrelIa nodzjlora

Tithonia divers ifolia

Tridar procumbens

Wedelia chinensis

Wedelia trilobata

38 Zinnia elegans 24 2x A292OC2 1 2.00-0.79 1.07 25.73 12.86 43.36 29.55 45.66 1.59

39 Tagetes erecta cv. orange 48 4x A2B36C10 1 1.44-0.60 0.92 44.34 11.08 41.i7 18.89 44.06 1.14

40 Tagetes erecta cvpale yellow 48 4x A4B36 C8 2 1.71-0.72 1.01 48.27 12.06 40.74 22.82 43.27 3.62

41 Tagetes erecta cv. yellow 24 2x A2B8C14 1 1.20-0.67 0.81 19.51 9.76 28.34 18.10 44.38 0.40

42 Tagetes patula 24 2x A2B12C10 1 1.36-0.66 0.87 21.01 10.50 34.65 23.92 45.12 0.43

43 Chrysanthemum parthenium 18 2x A2B14C2 1 1.56-0.64 1.12 20.20 10.10 41.81 23.62 45.89 0.62

44 Crassocephalurn crepidioides 40 4x A6B32 C2 3 1.92-0.78 1.42 57.11 14.27 42.22 21.67 42.07 4.52

46 Notonia grandiflorn 20 4x A2B18 1 2.20- 1.30 1.62 32.55 16.30 25.71 20.20 45.46 4.50

47 Sonchus oleraceus 18 2x A2914C2 1 1.36-0.79 0.93 16.88 8.44 26.51 17.92 44.90 0.33

PL - Ploidy level, KF - Karyotype formula, CP - Chromosome pairs with secondary constriction, RCL - Range of chromosome length in pn, ACL - Average chromosome length in p, TCL - Total chromatin length in p, CLH - Chromatin length of haploid complement in p, DI - Disparity index, VC -Variation coefficient, TF -Total forma percentage, Volume - Total volume of chromosome.

Chromosome number E l % of Plants

Fig.48 Range of chromosme numbers recoganized in the present study

Base Number El% of Plant

Fig.49 Range of Base Numbers recoganised in the present study

Fig.50 Range of ploidy level recoganized in the present study

Elephantopus scaber Phyllocephalurn rangacharii Vemonia cineree

Fig.51: Comparison of the major karyotypic parameters in various taxa of the tribe Vernonieae

Fig.52 : Comparison of the major karyotypic parameters in various taxa of the tribe Eupatorieae

Conyzs bonaflensis Conyza canadensis Dichrocephala Erigemn chrysanthemifofia mucronetus

Fig.53 : Comparison of the major karyotypic parameters on various taxa of the tribe Astereae

Blurnee lecem BIumea mollis Blumea Sphaemnthus Vima indica oxyodont8 indicus

Fig.54 : Comparison of the major karyotypic parameters on various taxa of the tribe lnuleae

QTCL

TF%

Acanfhospennum Bidens pilosa Eclipfe prostrata Galinsoga parviffora hispidurn

Fig.55 : Comparison of the major karyotypic parameters on various taxa of the tribe Heliantheae

Cosmos bipinnatus cv Cosmos bipinnalus cv yellow Cosmos caudatus orange

Fig.56 : Comparison of the major karyotypic parameters in different cyfotypes of the genes Cosmos

Melampodium Parthenium Sigesbeckia Synedrella nodflora paludosm hystemphorus orientalis

Fig.57 : Comparison of the major karyotypic parameters on various taxa of the tr~be Heliantheae

Spilanthes calve Spilanthes ciliafa Spilanthes radimns Spilanthes uliginosa

Fig.58 : Comparison of the major karyotypic parameters in different cytotypes of the genus Spilanthes

Tifhonia Tridex Wedelta Wedelia Zinnia elegans diversifolia procumbens chinensis trilobata

Fig.59 : Comparison of the major karyotypic parameters on various taxa of the tribe Heliantheae

Tagefes erecta cv Tagetes erecte cv Tegetes erect@ ev Tegetes pefula orange pale yellow yellow

Fig.60 : Comparison of the major karyotypic parameters in different cytotypes of the genus Tagetes

Chryssnthemum Crassocephelum Emilia sonchifolia Nofonia Sonchus partbenium crepidioides grandflora oleraceus

avc I UTF%

Fig.61 : Comparison of the major karyotypic parameters on various taxa studied

DISCUSSION

a) Chromosome numbers in the genera investigated

Chromosome number determination from fifty seven populations attributed to

forty seven species from thirty four genera of Asteraceae were made.

Cytologically the family is variable. The chromosome spectrum varies from

2n = 10 to 2n = 78. With majority of species concentrated in the number 2n =

18, followed by 2n = 24, 2n = 3t3 and 2n = 40. The presence of identical

numbers in unrelated genera is a vary noteworthy feature in this family. The

presence of such widely differen series of chromosome numbers in the

species of even the same genus and in genera placed under different tribes

indicated that the different chromosame numbers can be derived one from the

other.

The counts confirm the chromosom: numbers of all previous reports in some

species or are consistent with one of variable numbers reported by several

authors in other species. Of the 'ifty seven plants in which chromosome

number determinations were made hventy six (55.31%) are diploids and

twenty one (44.68%) are polyploids. High chromosome numbers such a . n =

15, 16,17 and 25, have been considered to be the result of polyploid increase

followed by dysploid loss (King and Kobnison, 1987).

Sub family: Tubuliflorae

Tribe: Vernonieae

In this tribe three taxa belonging to three genera have been examined. The

chromosome number of phyllc~cephalum rangacharii is 2n = 18,

Elephantopus scaber is 2n = 22 and Vernonia cinera is 2n = 18. According to

the previous reports (Shetty, 1967; Narayana, 1979; Ayyangar and

Sampathkumar, 1969a; Sharma and Sarkar, 1967-68; and Bir and Sidhu,

1980); the somatic chromosome numbers evaluated in these species are 2n =

18 (Phyllocephalum rangacharir) 2n = 18, 22, 44 (Elephantopus scaber) and

2n = 18, 36 (Vernonia cinerea).Tt~is seems to be a confirmation of an earlier

report made on these taxas.

Tribe : Eupatorieae:

Five genera have been examined. The chromosome count made on the lone

member investigated in the genus Adenostemma is 2n = 20 (Adenostemma

lavenia). This somatic chromosome number agrees with the previous reports

(Powell and Cuatrecasas, 1970; Mi yagi, 1971). The second genus Ageratum is

seems to be plastic. In the present study the genus Ageratum represented by

two species. The chromosome number ranges from 2n = 20 (A. conyzoides) to

2n = 40 (A. haustonianum). Somatic variations are also found in Ageratum

conyzoides (2n = 30). This chromosome count has not been reported so far in

this species. However, it is a new count. Reported somatic chromosome

numbers of this genus are 2n = 20, 38 and 40. (Bir and Sidhu, 1980; Olsen,

1980; Mehara and Remanandan, 1975; Sharma and Varma, 1960; Jansen and

Stuessy, 1980). This variation fourid for the chromosome number results from

the establishment of different tytotypes giving a numeric chromosome

polymorphism for the species. For species Chromolaena odorafa, the somatic

chromosome number is found to txe 2n = 60. Eupatorium triplinewe root tip

cells showed 2n = 50 and both these populations, agree with the previous

reports (Olorode, 1974a; Khonglam and Singh, 1980). The counts made on

this genus Mikania reveal the codominance of two chromosome numbers 2n =

34 and 2n =36. Data in the literature also suggest a numerical chromosome

variation for the Mikania cordata species as 2n = 30, 34, 36 and 38. (Fedarov,

1969; Rabakonandrianina, 1987). Cytogenetic studies have shown that among

population of the same species there may be numerical variation, as o b s e ~ e d

by Maffie (1996) in Mikaria micrantha pollulation, where a numberical

variation of 2n = 36 to 2n = 72 war recorded.

Tribe: Astereae.

Four taxas belonging to 3 genera have been examined. The genus Conyza is

represented by two species. One with 2n = 54 (C. bonariensis) and the other

with 2n = 18 (C.canademis) in the present study. A review of literature

reveals that the chromosome numner in Conym ranges from 2n = 18 to 2n =

54, with a high frequency for the number 2n = 18 (Fedarov, 1969).

In Dichrocephala chrysanthemifolia the somatic chromosome number found

with 2n = 18 agrees with the prc:vious report (Mathew and Mathew, 1978).

Only one species of Erigergn studied was found to be with 2n = 18

(E.mucronnhrs). The previou!; reports show 2n = 18, 32, 34 and 36 (Carano,

1921; Mehra and Remanandan, 1974). Thus this species seems to be highly

plastic in its chromosome number.

Tribe.: Inuleae.

Only three genera have been examined. The genus Blumea the chromosome

number 2n = 18 and 2n = 28 in B.mollts and B.oxyodonta respectively and

2n = 36 in one cytotype (B.l~cera) investigagted. The result of the cytogenetic

analysis of the B.mollis populations also show a chromosome variation with

2n = 16 chromosomes. Chrc~mosome counting of the same species may show

different chromosome numbers, from the distinct cytotypes of the species. The

chmmosome numbers obsemed in members of Inuleae range from 2n = 14

to 28 (n = 7, 8, 9, 10, 11, 12 and 14) (Panchami and Vijayavalli, 1998). The

results of the cytogenetic analysis of the species Sphaeranthus indicus show a

chromosome variation will1 2n = 16, 2n = 18 and 2n = 20 and the most

frequent number was 2n = 20. This variation found for chromosome number

results from the establishment of different cytotypes, giving a numeric

chromosome polymorphisn~ for the species. In one member investigated in

the genus Vicoa, Vicoa ind;ca possesses 2n = 18. Previous studies (Mehra and

Sidhu, 1960) support the dominance of this number in Vicoa indica.

Tribe: Heliantheae

The chromosome numbers of hwenty two plants were observed; which belong

to 15 genara and 18 species. Chromosome numbers observed in the present

study were 2n = 22 in Acantho,permum hispidum; 2n = 72 in Bidens pilosa ;

2n = 24 in Cosmos bipinnatus and C. caudatus; 2n = 22 in Eclipra prostrata;

2n = 32 in Galinsogapmifror~~; 2n = 24 in Melampodium paludosm; 2n = 36

in Parthenium hysterophores; 2n = 30 in Sigesbeckia orientalis; 2n = 78 in

Spilanthes calva and S. radicans; 2n = 52 in S. ciliata and S. uliginosa; 2n =

40 in Synedrella nodifora; 2n = 34 in Tithonia diversifolia; 2n = 36 in Tridm

procumbens; 2n = 50 in Wedelia chinensis and in Wedelia trilobata and 2n =

24 in Zinnia etegans.

Data in the literature also sug:gest a numerical chromosome variation for the

Bidens pilosa species from 2n = 24 to 2n = 96 (Mariano and Morales, 1999).

The previous reports show that the number 2n = 72 is the most frequent, with

about 70% of the population coinciding with this results. Generally the

polyploidid organism have a greater genetic plasticity, due to a greater

genetic variability present in the genome.

On the contrary, Cosmos b i p i n m s is characterized by intraspecific

variations. The chromosome 2n = 24 occur in two cultivars (cv orange and cv

yellow) and C.bipinnates c\ oranage also show variation 2n = 22. The

occurrence of different cytoiypes in the same species is not very stable and

very alter either by the duplication or loss by individual chromosome (Morton,

1962). The dominance of the chromosome numbers 2n = 52 and 2n = 78 in

the genus Spilanfhes is very well established in literature. (Mathew and

Mathew, 1978; Mehra and R~:manandan, 1969).

hesent cytogenetic analysis of the Eclipta prosfmta shows a chromosome

variation with 2n = 18 and 2n = 22 observed in many plants analysed. This

somatic chromosome numbers agree with the previous report (Mohan et al.

1962). The chromosome number counted in the present analysis (2n = 22,24,

30, 32, 34, 36, 40, 50, 52 and 78) confirmed in all the populations studied in

this tribe, agrees with the previous reports.

Tribe: Helinieae

Seven populations belonging to the lone genus Tagetes have been examined.

This genus is characterized by intraspecific variation. The result of the present

cytogenetic analyses of the s x Tagetes erecta populations show chromosome

variation with 2n= 18,2n = 2 1,2n = 24 and 2n = 48 chromosome and the most

frequent number was 2n = 24 observed in three populations analysed. Only

one plant of Tagetespatula species studied was found to be with 2n = 24. As

regards the chromosome number this genus seems to be heterogenous with the

frequent occurrence of the somatic numbers 2n = 18, 24 and 48. A similar

trend has also been observed in literature.(Mathew and Mathew, 1980;

Shanna and Sarkar, 1967-1968; Federov, 1969). Intraspecific variation is thus

very well pronounced in this taxa. Variation in chromosome number may be

due to nondisjunction, somatic reduction or even by partial endomitosis.

Nondisjunction, in the somatic tissue, involves unequal anaphasic separation,

which results in unequal distribution of chromosomes in the daughter nuclei.

Tribe: Anthemideae

One plant has been examined. For the taxa Chrysanthemum parthenium, the

somatic chromosome number is found to be 2n = 18. The absence of any

somatic variation numbers suggests the stability of the genomes.

Tribe: Senecioneae

Three genera have been examined. Crassocephalum crepidioides root tip cells

showed 2n = 40. In the present study it is revealed that Emilia sonchifolia and

Notonia grandgora possess 2n = 10 and 2n = 20 respectively, agrees with the

previous reports (Gill et al., 1980; Narayan and Shukur, 1968; Federov, 1969).

Sub family: Liguliflorae

Tribe: Cichorieae

Sonchus oleraceus is the lone plant examined in this tribe. This taxa showed

the chromosome number 2n = 18. This is in conformity with the reports made

on the same taxa. However, 2n = 16, 18, 32 and 36 were also reported

(Federov, 1969) and frequent number is 2n =IS. Hence this species seems to

be highly plastic as far as the chromosome number is concerned.

b) Basic chromosome number

Basic chromosome number forms one of the widely used characters in

formulating phylogenetic speculations. It is generally regarded as a

dependable and stable marker of the direction of evolution and widely being

used in formulating phylogenetic speculations (Jones, 1970, 1974, 1978). It is

known that many basic chromosome numbers are involved in the origin of the

polyploid series in Angiosperms (Grant, 1982).

Based on the previous reports and the present investigation of somatic

chromosome number, an attempt is being made to discuss the possible

direction of basic chromc~some number evolution in this family. The

investigations are conducted on forty seven taxa belonging to thirty four

genera of nine tribes. The basic chromosome numbers vary widely in this

family and thus it appears that the family is a highly evolved one. Both

primary and secondary base numbers are involved in the evolution of the

various taxa studied. The primary base numbers (XI) range from 5, 7 and 9

and secondary base numbers (X2) range from 10, 11, 12, 13, 15, 16, 17, 18

and 20. The basic number X = 9 was found in majority oFthe members (30%)

followed by the numbers X. = 10, X = 12 and X = 11 with percentagel9,17 and

13 respectively. It is likely that protopolyploidy plays an active role in the

evolution of these basic numbers (Fujita, 1970). The ancestral basic

chromosome number of /isteraceae appears to be X = 9. The frequency of

polyploidy was 23% (Tomb et al. 1978).

Grant, (1981) proposes the original primary base numbers of angiosperms to

range From X = 7 to 9 and they seem to be ancestral in the phylogenetic sense.

From these primary base numbers many polyploid series develop both by

autopolyploidy and amphipol!lploidy. The latter involves both hyper and

hypoploidy (Fernandes and l,eitao, 1984). Thus it can be confirmed that

polyploidy had influenced and played a role in the evolution of base numbers.

Sub family: Tubuliflorae:

Tribe: Vernonieae.

The common base numbers of this tribe found in the present investigation are

X = 9 and X= 11. Phyllocephalum and Vernonia possess X = 9 and

Elephantopus X = 11. Literature evidences reveal the dominance of two

common base numbers X = 9 and X = 10 in Vernonia (Ayodele, 1994).

Tribe: Eupatorieae

In this tribe the common base: numbers found are 5, 10 and 18. The basic

chromosome number found in the lone member investigated in the genus

Adenostemma was primary in llature with X = 5 chromosomes. Other 3 genera

Ageratum, Chromolaena and Eupatorium are monobasic with the secondary

number X = 10, found in all the four investigated members. The existence of

these basic numbers was confirmed by Watanabe, (1990). Bremer et a1.(1994)

postulated that an initial reducrion in base number in the tribe Eupatorieae was

followed by an increase in the basic chromosome number.

A broad range of basic chronlosome numbers from X = 4 to 25, has been

reported in this tribe. 73% of the reported genera, and 53% of the reported

species have chromosome numbers based on X = 10. Thus the predominant

chromosome number among species, genera and sub tribes X =I0 was

doubtlessly regarded as the uitimate base number in this tribe by most of the

previous workers (Watanabc:, 1995). The basic chromosome number of

M i h i a cordota in the preser~t investigation is X = 18. Two base chromosome

numbers of I7 and 18 are also confirmed in Mikmria cordata by many

workers. There are many reports of 2n = 34, suggesting the occurrence of X

= 17 (Rabakonandrianina and Carr, 1987). On the other hand, some workers

(Grant, 1953; Turner and King,1964) have suggested that species with the

ancestral base number of X = 5 and 4 might have given rise through

successive alloploidy to those taxa with base number of 9, 10 and 17.

Tribe: Astereae:

The basic chromosome numbers found in the investigated members of this tribe is

X = 9. The present study includes 3 genera. The genus Conyza is mono basic

with the X = 9, found in two investigated members (C. bonmiensis, and C.

canadensis). Dichrocephala and Erigeron, both are diploids with

chromosome number 2n = 18. Thus the basic number is X = 9. Robinson et

al., (1981) has proposed X = 10 as the base number for the entire Astereae.

Tribe: Inuleae:

The basic lines in the tribe are >: = 7, 8,9, 10, 11 and 12. It is suggested that X

= 5 could be the ancestral basic number in the tribe. In the genus Blumea 4

basic numbers exist such as X .= 8,9, 10 and 1 1. It is suggested that X = 10 in

BIwnea could be the earlier evolved condition from which the lower

constitution found among thc: South Indian taxa which has evolved by

progressive reduction through the formation of B-chromosomes followed by

their elimination ( 8 t 9 t 10 +11) (Panchami and Vijayavalli, 1998). The

occurrence of 2 numbers (7 and 9) in 3 different species of Blumea,

investigated in the present study appears to c o n f m this suggestion. Similar

suggestions have been made by a few earlier workers (Mathew and Mathew

1987). But Mehra and Remanandan, (1975) suggested that Blumea is based

on X = 11. The basic numbers in other genera investigated in the present

study are X = 10 (Sphaeranthus) and X = 9 (Vicoa). In contrast Turner

(1970), when discussing possible base numbers in this tribe speculated that X

= 4 and 5 may be ancestral for the tribe with the former giving rise to X = 8

and X = 12 and aneuploid number of X = 7 and X = 13, respectively. Under

this scheme the base of X = 5 given rise to genera with n = 10 and

subsequently aneuploid derivatives with n = 9 and 11. This hypothesis was

suggested in past because of the apparent absence of taxa based on X = 6.

Tribe: Heliantheae:

Chromosome numbers also vary considerably in the tribe Heliantheae, ranging

from X = 4 to X = 19. However, X = 10 is rare, while X = 8 and 9 are

common and higher base numbers of X = 17, 18 and 19 are also prevalent

(Stuessy, 1977). h e basic chromosome numbers found in the investigated

members of this tribe include X = 9, 1 1, 12, 13, 17 and 20. Both ascending

and descending dysploidy, autopolyploidy and amphipolyploidy were found to

be responsible for the evolutic)n of various taxa coming under this tribe. Most

of the cytologically known genera are monobasic while a few other with

dibasic and polybasic conditions are also present. In the genus

Acanthospemum, which is 3 monobasic genus with X = 11. Most of the

previous workers are also of the opinion that X = 1 1 is the original number. In

the present investigation suggest X = 12 for the Bidens pilosa species. This

result c o n f m the result of Bamso (1991) of X = 12 for the Bidens genus.

Data in the literature also suggest a numerical chromosome variation for the

Bidenspilosa species from 2n = 24 to 2n = 96 (Mariano and Morales, 1999).

Cosmos the genus is monotmsic with the secondary number X = 12, found in

all the three investigated n~ernbers. Literature survey confirms the existence

of X = 12 in Cosmos (Mathew, 1978). Two different chromosome numbers

have been reported for this species by earlier workers such as n = 12 and n =

1 1 which indicate that this species exist at least in two cytotypes .

The genus Eclipfa exhibits the secondary basic number X = 11. Previous

workers also confirm the existence of X2 = 1 1 in Eclipta, hence chance for the

occurrence of amphipolyploidy from the primary base numbers XI = 5 and

XI = 6 as well as ascending or descending dysploidy from the respective

secondary base numbers are equal during the process of evolution.

Galinsoga parvifora in this present investigation shows n = 16. In the

absence of authentic basic chromosome number reports on this species of the

genus, the question regarding the basic number remains a matter of

speculation. The basic numter of this species may be X = 16. The base

number found in Melampodium paludosm is X = 12 which is secondary in

nature and well supported by an earlier study (Mathew, 1978). The basic

chromosome numbers in other genera are X = 9 (Parthenium and Tridar) X =

IS (Sigeskckia) X = 17 (Tithoiiia) X = 20 (SynedreNa).

The genus Spilanthes is monobasic with the secondary number X2 = 13;

found in all the four investigated members. The existence of these basic

numbers were confirmed by Mathew (1978). This secondary basic number X

= 13 might be a case evolved through polyploidy (Gill, 1970) involving the

primary base numbers X = 6 and 7. The present cytotypes with n = 39 and 2n

= 78, obviously constitute a polyploid series on the n = 26 type reported by

Mehra and Ramanandan, (1974) The reported occurrence of types with n = 7

as well as n = 12 indicates a pmsible polyploidy origin of the n = 26 type

through n = 13 which in turn originated by hybridisation of two lower

chromosomal types such as n = 7 and n = 6.

Two species of Wedelia examined in the present study reveals X = 10 is the

basic number of this genera. Brised on the available reports of basic numbers

in the genus Wedelia suggested a basic number of X = 10. But based on the

occurrence of n = 15 and 25 in Indian species Mehra and Ramanandan, (1974)

on the other hand, have suggested n = 5 as the possible basic number of the

genus. If X = 10 is taken as the basic number of the genus, the present two

species should be pentaploid. The basic chromosome number found in the

lone member investigated, in the genus Zinnia (Zelegans) was secondary in

nature with X = 12 chromosomc s

Tribe: Helinieae:

The tribe Helinieae possess chromosome numbers ranging from X = 3 to X

= 20 (Ito et al., 2000) All the four investigated members of the genus Tagetes

are multiplies of the secondary basic chromosome number X = 12. Evidences

from the literature reveal the predominance of this base number in the genus.

This secondary base number can be found only through autopolyploidy

(Stebbins, 1966) from the primiuy basic number, X=6.

Tribe: Anthemideae:

Chrysanthemum parthenium (2 n= 1 S), the lone member cytological1y screened

in this tribe reveals the presence of the primary basic chromosome number X

= 9, which has been confirmed by earlier reports.

Tribe: Senecioneae:

The base number for the tribe is X = 10 which is found in various multiples

(Robinson et al., 1997). From the present evolution both primary (X = 5) as

well as secondary (X = 10) base numbers seem to be prevalent in this tribe.

The secondary basic number X = 10 has been well established in

Crassocephalum (2n = 40) and Notonia (2n = 20). In Emilia sonchfofia the

somatic number found from this present study is 2n = 10. Thus the basic

number is X = 5. The higher basic number (X = 10) is considered to be

derived from lower number X = 5 by autopolyploidy (Stebbins, 1966).

According to Robinson (1997) occurrences of n = 5 in Emilia, n = I0 in some

Senecio, and n = 14 to 16 in members are considered as reduction.

Tribe: Cichorieae:

The basic chromosome number found in the lone member investigated,

Sonchus oleraceus was primary in nature with X = 9 chromosome. A new

base number (X = 10) in this genera is reported by Razaq et al. (1 994 ).

c) Polyploidy

Polyploidy is a very wide spread cytogenetic phenomenon found in over 30%

of dicotyledons and 50% w' monocotyledons (Love and Love, 1975). It is a

mechanism which involves multiplication of the whole chromosome

complement and there by an increase of gene number and variety, producing

radically different well adopte,d genomes (Stebbins, 1950). Polyploids are

considered to be more hardy and adaptable to extreme climatic conditions

(Hagemp, 193 1; Tischler, 1935; Love and Love, 19424 1943).

Polyploidy is one of the best genetical and evolutionary progresses, which has

greatly contributed to speciation and evolution of higher plants (Gottschalk

1985). This is mainly due to the ability of polyploids to increase the chances

of fertilization by breaking reproductive bamers, which permit natural

selection and establishment of species even under adverse environmental

conditions (Winge, 1917; Stebbins, 1971, 1974). There can be no doubt that

polyploid species are highly successful. A comparison of the geographic

distribution of polyploids ant1 diploids in plants show a greater adaptability of

polyploids (Love and Love, 1943). However, the evolutionary potentialities

of a diploid are likely to be g=ater in the long run (White, 1937).

The family A s t e m a e is characterised by relatively high frequency of

polyploidy. The present study reveals that herbaceous elements predominate

as compared with the shmb~y elements of the family. Growth habit is one of

the factors, which influence the frequency of polyploids in angiosperms

(Baquar, 1976). In Angiosperm, the highest percentage of polyploidy was

found in perennial herbs while annuals and woody plants have lower

percentage of ploidy (Stebbins, 1938; Fagerlind, 1944). Among the

polyploids, the majority are tetraploids. The various genera which show a

predominance of polyploicly include Adenostemma, Ageratum, Chromolaenu,

Eupatorium, Conyza, Blumea. Bidens, Parthenium, Spilanthes, Tridax,

Wedelia, Tagetes, Crassocephalum and Notonia.

Sub family: Tubuliflorae.

Tribe: Vernonieae.

The tribe shows a lower percentage of polyploids. Among the three members

studied, all are diploids with primary and secondary basic number X = 9 and

X = 11.

Tribe: Eupatorieae.

Different degrees of polyploidj has been observed in this tribe. The role of

polyploidy in the mechanism ol'speciation is obvious in the tribe Eupatoreae.

The cytological data obtained from the 6 members of this tribe indicated that 5

members are polyploids. MlRania cordata (2n = 36), the lone diploid

representative, exhibits a aneuploid variant number 2n = 34. Ageratum

conyzoides and Ageratum hmcstonianum (2n = 4X = 40) Chromolaena

odorata (2n = 6X = 60) and Eupatorium triplinewe (2n = 5X = 50) are

polyploids based on X = 10. There is no sign of a polypoid state at 2n = 20. In

addition, new polyploid series (3X, 4X, 5X and 6X) based on X = 10 have

developed extensively in the genera of Eupatorium and Chromolaena (Ito et

al. 2000). In the course of eletkrophoresis studies, found that diploid species

of Eupatorium with a chromosome number of n = 10 had extensive gene

duplications (Yahara et al. 1989). This finding casts further doubt on the

hypothesis that X = 10 was the ultimate base number of Eupatorium as well as

Eupatorieae, because diplolid vascular plants have a minimum highly

observed number of isozymes (Ciottlieb, 1981). A.conyzodies (2n = 40) exhibit

somatic variant (2n = 30), it is ;I triploid compliment of the basic set X = 10

chromosomes. Another member investigated in this tribe Adenostemma (2n =

4X = 20) is a tetraploid with the basic chromosome number X = 5.

Tribe: Astereae:

Out of four taxa investigated, one exhibit polyploidy. Two species studied

under the genus Conym, one is hexaploid (C. bonariensis) and other is diploid

(C.canadensis) These two sets ;ire evolved from the base figure X = 9. Other

diploid species observe in this tribe are Dichrocephala chiysanthemifolia (2n

= 18) and Erigeron mucronatus (2n = 18). All the investigated members of

this tribe are characterised by the absence of variants. The stability of the

chromosome number (2n = 18) indicated that distinctly well differentiated

genomes are involved in the origin of these diploids.

Tribe: Inuleae.

Out of the three taxa investigated in the genus Blumea, B. lacera and B.

Oxyodoto are tebaploids with 2n = 36, and 2n = 28 respectively. The diploid

BIumea mollis possess a somatic number 2n = 18. Here the cause for

ployploidy in the two species (B. lacera and B. oxyodonta) may be due to the

parallel evolution of two basic figures X = 9 & X = 7 and formation of

multiplies which develop into two series of polyploids during the course of

evolution. The diploid memter B. mollis (2n = 18) exhibits a t e t m m i c

variant number 2n = 16. This might have been probably caused by

multipolarity that leads to unbalanced chromosome compliment.

Sphaeranthus indicus is diploid with a basic set of X = 10 also exhibit

aneuploid somatic variants 2n = 18 and 2n = 16. Aneuploidy is very common

in this tribe at both generic and specific levels. It is caused by the gain or loss

of one or more chromosomes from the haploid set. The lone species of Vicoa

examined in this study, Vicoa indica is a diploid cytotype (2n = 18) with the

base number X = 9.

Tribe: Heliantheae:

In contrast to the other tribes, it shows a lower percentage of polyploids

among the members studied. Robinson et al., (1981) proposed that ancient

polyploidy played an important role in the early history of the Heliantheae,

based on the distribution of chromosome number. Acanthospermum hispidum,

the lone member of the genus Acanthospermum investigated in the present

study is diploid in nature (:ln = 22) with the basic figure of X = 11. The

result confms the result of Barroso, (1991) of X = 12 for the Bidens genus

and this is the most common member. Cytotypes with different ploidy levels

were found in previous reports, derived from X = 12, thus showing that

polyploidy were the main evolutionary process acting in B. pilosa (Mariano

and Morales, 1999).

In Cosmos the chromosome number counted, 2n = 24 which confirmed in both

populations (C. bipinnatus anti C. caudatus), agrees with the previous reports.

It belongs to a diploid level with basic number X = 12, which is the most

common in the genus, C. bipi.mafus CV. orange (2n = 24) exhibit aneuplopid

somatic variant (2n = 22). Ar~euploidy is common in this genus. It is caused

by the gain or loss of one or rnore chromosomes from the haploid set (White,

1937). The genus Eclipfa with one studied species shows, 2n = 22 based on X

= 1 1. This agrees with the pn:vious reports. Somatic variant (2n = 18) is also

found in this species which are multiples of the lowest one. The incidence of

polyploidy is very much striking in the genus Spilanthes. All the members

studied showed tetraploid or hexaploid condition, with the basic number X =

13. A perusal of the literature shows that so far all the investigated Spilanthes

species are at polyploid level. The present cytotypes with n = 39 and n =26

obviously constitute a ployploid series reported by Mehra and Remanandan,

(1974). The reported occurrence of types with n = 7 as well as n = 12

indicates a possible polyploid origin of the n = 26 type through n = 13 which

in turn originated by hybridisation of two lower chromosomal types such as

n=7and n = 6 .

The other members investigated in this tribe Galinsoga parvijora (2n = 2X =

32), Melampodium paludosm 1:2n = 2X = 24). Siegesbeckia orientalis (2n = 2n

= 30), SynedreIla nod~$ora (2n = 2X = 40), Tithonia diversifolia (2n = 2X =

34), and Zinnia Iegons (2n = :!X = 24) are diploid with basic number X = 16,

12, 15, 20, 17 and 12 respectively. The high basic numbers considered as a

secondary one. Such a high basic numbers might have originated either

through polyploidy followed by aneuploidy or dibasic polyploidy involving

the primary base number X = 7,8 and 9.

Other two taxa investigated in h i s tribe, Parrhenium hysterophores and Tridax

procumbetas, reveal the existence of tetraploidy from the basic figure X = 9.

An increase in the number of ~:hromosomes through autopolyploidy provides

increased possibilities for new gene combinations, which are of considerable

importance in evolution. The genus Wedelia, which was found to exhibit

pentaploidy in two species investigated. Moreover the vegetative mean of

reproduction, which is prevalent in the investigated taxa seem to bear a

correlation with the high degrees of polyploidy. Polyploidization might have

lead to the establishment of new gene combinations that have triggered off

new developmental changes leading to a later shift towards the asexual mode

of reproduction. (Stebbins, 1980; Gustafsson, 1947b). Thus the polyploidy

and aneuploidy was found to play an important role in the evolution of

Wedelia.

Tribe: Helinieae:

The various cytotypes of the genus Tagetes exhibits polyploidy and varying

degrees of somatic variation. The delicately balanced system of gene

interaction in tetraploids is disturbed by the doubling of chromosomes,

resulting in the formation of somatic variants (Kuckuck and Levan, 1951).

Out of four taxa investigated in this genus, Tageres erecta cv. orange and

rerecta cv. pale yellow are :etraploids with 2n = 48. The diploids Tagetes

erecta cv. yellow and Tagete,~ patula possess somatic number 2n = 24 each.

Each though both the polyplc4d and diploid taxa of Tagetes are multiplies of

the basic figure X = 12, the liigher levels of ploidy attained by T. erecta cv.

orange and T. erecta cv. pale yellow probably point towards their greater

adaptability. The aneuploid and hypoploid variations found in their polyploid

taxa reveal the on going genetic and evolutionary processes which may help to

break the reproductive barriers enabling natural selection and thereby

speciation (Stebbins, 1974).

Tribe: Anthemideae.

The single taxa investigated in the tribe Chrysanthenum parthenium is

characterised by its diploid stales from the base figure X = 9.

Tribe: Senecioneae.

A brief review is offered by Robinson et al. (1997) of major chromosome

number variations in the senecioneae based on recent delimitation of the tribe.

According to him the base number for the hibe X = 10, which is found in

various multiplies. Some mc:mbers with a base of X = 9, considered an

aneuploid reduction from X = 10. Number based on X = 30 and aneuploid

reduction are found in many Australian Senecio. Three members are studied

in the present investigation, two are diploid, and one is a tetraploid.

Crassocephalum crepdioides (:!n = 4X = 40) and Notonia (2n = 2X = 20) have

the basic chromosome number X = 10; and Emilia sonchifolia (2n = 2 X = 10)

is X = 5. Occurrence of n = 5 in Emilia is considered as reduction.

Tribe: Cichorieae.

Sonchus oleraceus the lone t;vca investigated is diploid and with X = 9 as the

basic chromosome number

d) Karyomorphometrical analysis

In Angiosperms the specie; of several families both dicotyledonous and

monocotyledonous are found to exhibit a direct relationship between their

phylogeny and the chromosome constitution. The chromosomes being the

carriers of heredity, both 3tructural and numerical changes in them can

influence the genetic evolutionary process at work than do any other type of

changes. Detailed information regarding the chromosome architecture in

higher plants can thus serve as a useful tool to understand their systematic

relationships and for tracing the trend and direction of their evolution (Love

and Love, 1975).

Some of the major karyotyp characteristics of considerable evolutionary and

taxonomic significance are ( I ) differences in the absolute chromosome size (2)

differences in the position $of centTomere (3) differences in total chromatin

length (4) differences in karyotype formula and (5) number as well as position

of satellites.

Since, most of the members of Asteraceae possess small chromosomes the

detailed karyomorphological study by conventional method is not easy. So far

only a few plant species wen. reported for their karyomorphology. An image

analysis system provides a better opportunity for studying the various

chromosomal parameters. 'Illis method has only been used recently in plant

cytology and chromosome studies (Fukui, 1985, 1986). It appears to be a very

powerful tool which to generate the quantitative chromosome data and

idiograms, which cannot be obtained by conventional methods. This system

has achieved a drastic reduction of the researchers' time and efforts while

maintaining a high standard of information in the quantification and

karyotyping of chromosomes. It has become possible to obtain various kinds

of quantitative data on the chromosome images. The length of the

chromosomes and the ratio between the short and long arm values has

represented almost all thr: numerical information available on the

chromosomes for the past decades. It has become however possible to obtain

not only one dimensional daia of the chromosomes such as length, but also

two and three dimensional data of area and volume within a limited time by

using image analysis system. Also it is possible to make an accurate pairing

by PerimeterIArea (PIA) ratio mainly in those cases where chromosome sizes

are really small. Relative chromosome Length (RL) and Arm Difference ratio

(AD) are also considered to find out homologous chromosomes for accurate

pairing. Chromosome pairs whose ADS and RLs are not significantly different

(P<O.OS) were judged as morl~hologically identical (Watanabe et al. 1990). In

addition to this imaging techniques provide pseudo colouration, which is a

very useful tool for identifying the primary and secondary constriction of

small chromosomes very c1t:arly. Idiograms can be prepared semi

automatically and by using computer devices. By the traditional methods of

analysis this procedure would be more difficult due to the small size of

chromosomes. At the same time biases in the analytical processes originating

from the differences in the researchers skill and experiences can be minimised

by employing this method. Hence this method would provide useful

information for chromosome analysis and may be helpkl as an essential tool

in chromosome research (Fukui, 1988; Fukui and Kakeda, 1990; Iijima, 1991).

The general feature noted i r ~ the family Asteraceae is the wide range of

chromosomes with small sized chromosomes in most of the species.

However, the chromosome c:omplements in the various members differ in

minute karyotypical details (vide Table 49). With regard to the gross

morphology, chromosomes a-e nearly sub median to nearly median in nature.

The chromosome range from1 2.54 to 0.41 pm in length. The chromosomes

with secondary constriction ranges from 2 to 8 in number. The average

chromosome length (ACL) baries from 0.74 to 2.3 pm. The total chromatin

length (TCL) shows a very wide variation with 14.82 being the minimum and

90.32 being the maximum value. The disparity index values ranges between

18.13 - 48.63, the coefficier~t of variation ranges from 13.49 - 35.97 and total

chromatin index (TF%) ranges from 40.3 - 50.74.

These variations found in the karyotypic parameters suggest that Asteraceae

members are characterized by symmetrical to slightly asymmetric karyotypes.

An increase in the range of chromosome length as well as the increase of sub

metacentrics at the expense of metacentrics is accompanied by an increase in

the coefficient of variation li:ading to a symrnelry (Stebbins, 1958). Thus

karyomorphological studies are of considerable importance in order to throw

light on the phylogenetic '-elationship among taxa of flowering plants

(Iwatsubo and Naruhashi,1991).

Sub family: Tuhuliflorae

Tribe: Vemonieae

Three genera represented in the present study are diploids. As regards the

chromosome with secondary constrictions Phyllocephalum rangacharii and

Vemonia cinerea possesses four chromosomes while Elephantopus scaber has

only two. The karyotype o!' these taxa is somewhat symmetrical and thus

shows primitiveness. Comparatively lower variation wefticient and higher

TF% is also primitive featun:. The range of chromosome length is lesser in

Elephantopus scaber as compared to other two members. Normally a low

disparity index value correspc~nds to the homogeneity of chromosomes in most

of the higher as well as lower plants (Mohanty et al.1991).

Tribe: Eupatorieae.

Five genera studied for their detailed karyomorphology. Chromosomes are

moderately small with symn~etrical karyotype except Chromolaena odorata.

In three members (Adenosternma, Chromolaena and Eupatorium) the absence

of 'C' type chromosome is a speciality. The differences observed in the

karyotype formula (KF), averase chromosome length and chromatin length of

haploid complement (CLH) among different taxa might have been probably

due to minute structural alterations of chromosomes. Speciation depends more

on chromosomal rearrangements and mutation of individual genes, than on

changes in the total amount of genetic content (Stebbins,l959). The high

value of average chromosome length shown by Chromolaena probably show

its primitiveness, where as the lower value for this parameter found in Mikania

denotes its evolved nature. A decrease in chromatin length is one of the

factors responsible for evolution of higher plants (Babcock and Cameron,

1934). The comparatively high disparity index (Dl) value found in Ageratum

followed by Mikania cordata corresponds to the heterogeneous assemblage of

chromosomes in these taxa.

Tribe: Astereae.

Karyomorphology of four taxa have been studied. The karyotype in these taxa

studied is found to be more or less homogenous and symmetric. The

chromosomes are found to t)e medium in size. All the members except one

species of Conyza (C. bon0riensi.s ) are diploid. Number of chromosomes

with secondary constriction is two in all the taxa studied. Karyotype formula

is symmetrical in all the cases except C.bonariensis, with the absence of 'C'

type chromosomes. All the other parameters (Dl, VC and TF%) seems to be

more or less symmetrical i n all these investigated members. A symmetric

karyotype is considered to t ~ e a primitive one (Stebbins, 1959). Even though

the karyotypic features of these members show general uniformity, in finer

details they appear to show recognizable difference with regard to the

distribution of secondary constrictions, centromere position of a few

individual chromosomes and there was no appreciable intra karyotype size

differences. It is remarkable that only minute structural alterations exhibited.

In the light of chromosome data and karyomorphological information of four

members reported here, it appears that both numerical and structural alteration

in chromosomes have not played any major role in speciation and evolution of

this tribe.

Tribe: Inuleae.

Karyomorphology of five taxa have been studied. The different species of

Blumea are exceedingly variable both in chromosome numbers and in

morphometric characters of their karyotypes. This variability of the genus

evidently reflects an important side of its evolution. The number of

chromosomes with secondary constrictions varies in different species. In

diploid taxa they are one pair ir~ number. The tetraploid species possess one to

two pairs of satellite chromos~~mes. The three species are characterized by

their homogeneous symmetrical karyotypes with lesser range of chromatin

length, a primitive condition. Among the karyotype of five taxa Vicoa indica

exhibits a short sized chromosomes, comparatively low values of average

chromosome length, disparity index as well as variation coefficient. From the

table 49 it is clear that the higher values for average chromosome length,

chromatin length of haploid complement, along with a low variation

coefftcient reveal primitivene:;~ of Sphaeranthus indicus over Vicoa indica

and Blumea.

Tribe: Heliantheae

Twenty taxa were studied karyomorphologically. The data indicate that, all

the tax8 have more or less symmetrical karyotype, which is considered to be

primitive. On a close examination of karyotype of these members it reveals

that karyotype asymmetry is progressively greater among the higher

polyploids. Similarly karyoqpic size difference of chromosome which is

brought about by differential deletion of segments of individual chromosomes

as well as through occurrence and establishment of unequal transaction

between non homologous chromosome is also seem to be greater among the

polyploids. The evidence thl~s indicate that the above factors which lead to

karyotype speciation also haw played some role, along with polyploidy, in the

evolution of genera.

For species in Spilanthes witn X = 13, the size ranged from 0.49 - 1.67 pm.

For species in Cosmos with >: = 12, the size ranged from 0.7 - 1.49 pm. For

species of Wedelia with X = 10, the size ranged from 0.41 - 1.15 pm.

Spilanthes and Wedelia species are polyploids compared to the diploid species

of Cosmos. Thus the significant chromosome difference between genera is

also confirmed. In Wedelidl and Spilanthes the lesser values for all the

parameters of karyomorpholclgy show its rather evolved nature. Such type of

variation is important from the evolutionary view point. Long chromosomes

with symmetrical karyotyp~: are further evidence of primitiveness

(Sharma,1984). In Tridaxproc-umbens even though the karyotype shows some

trend towards asymmetry, the higher values of average chromosome length,

chromatin length of basic corriplement reveal its trend towards primitiveness.

The chromosome pairs with secondary constriction are varying from one to

four in various taxa. The kar)~omorphological differences found among these

taxa fully justify that speciation and evolution has been principally affected by

minute structural alterations.

Tribe: Helinieae

Concrete conclusion cannot be drawn from the karyomorphological features

exhibited by the closely related genetic strains of Tagetes erecta (cultivars

orange, pale yellow and yellow) and Tagetes paluta . So it seems likely that

they represent three closely related lines has been found in evolution of their

morphological features. However, at the infra specific level Terecta cv pale

yellow is characterised by high value for major karyomorphometrical

parameters such as total chromatin length, average chromosome length.

chromatin length of haploid complement are considered as primitive

characters.

Tribe: Anthemideae

Chrysanthemum parrhenium is the lone member studied in the tribe. The

higher karyomorphological values exhibited by it denotes its primitive status.

However the vast difference of chromosome length and a high disparity index

value denote an advanced heterogeneous nature.

Tribe: Senecioneae.

Three genera were studied karyomorphologically. The number of

chromosomes with secondary constriction varies in different genera. In

diploid taxa they are one pair in number. The tetraploid species possess three

pairs of satellite chromosomc:s. Ernilia and Notonia are characterised by

higher values for the major karyomorphometrical parameters and

comparatively low variation coefficient. Thus these observations are in

advocacy with the primitive status of this genara among all the members

studied in this present investigation. Another notable feature of this species is

the absence of 'C' chromosonles.

Sub family: Liguliflorae.

Tribe: Cichorieae.

Sonchus oleraceus, the lone plant has been studied in this tribe is diploid in

nature with low chromosolne number (2n = 18). In this genus, the low

disparity index (Dl) value reveals the homogeneity of the chromosome

complement. The high 'IF% found in conjunction with a low variation

coefficient value reveal that S. oleraceus is a primitive plant. A high TF% and

low variation coeficient ,falues correspond to the primitive status in the

evolution of flowering plans. (Stebbins, 197 1 ).

e) Cytological evolution in Asteraceae

From the cytological observations made in the present investigation it can be

concluded that speciation and c:volution with this family has been possible as a

result of increase in variabilit) through changes in the base numbers, as well

as numerical and structural changes in chromosome numbers. The various

cytological phenomena like protoautoploidy, amphiploidy, ascending and

descending dysploidy might have resulted in the variability of base numbers in

the family. The wide range of :hromosome numbers observed in many genera

in the present investigation marks a significant role that aneuploidy and

polyploidy have played in the evolution of various taxa of the family at the

generic and species level. It also appears that various kinds of aberrations

have played a vital role in the evolutionary diversification of the family. The

mitotic and meiotic irregularities might have lead to structural and numerical

variations in the chromosomes of a species (Roy, 1998). Individuals with the

same chromosome number but with differences in karyomorphological details

reflect the ongoing evolutionary processes at micro level.

It seems probable that in Asteraceae, Robertsonian changes or mutations

might have also played an important role in the evolution of karyotype.

Drastically mutated individuals are usually unstable and unfit to survive in

nature because they express various degrees of weakness and chromosomal

aberrations leading to genetic sterility. However, some individuals canying

the changed chromosomal constitutions are well within their range of

tolerance. This was confirmed by the occurrence of normal meiosis in some

polyploids investigated. Moreovc:r, most of the taxa belonging to this family

have efftcient means of vegetative propagation. This ensures the survival of

these genetically altered types which otherwise would have faced exlinction

on account of sexual sterility imposed as a result of these changes.

Accumulation of such small changes can sometimes lead to a taxonomic

divergence in a species during the process of evolution. Thus meiotic

accidents may prove to be ir,ore useful than mitotic aberrations from the

evolutionary point of view, sirlce the meiotic abnormalities are hereditary and

likely to multiply and establish in a population.

M e very high chromosome number coupled with small size may indicate a

higher evolutionary status of !:his family. Comparing with other genera Emilia.

Notonia and Blumea posses3 large sized chromosomes which arc fewer in

numbers. But the chromoscmes of Agerafum, Euparorium, Spilan/hes and

Wedelia are small sized and more in number. The family Asteraceae seems to

be in a fairly active state of t:volution because of the quite common occurrence

of polyploidy and aneuploidy. Mutation of genes, structural changes in

chromosomes, non-disjunction, chromosomal rearrangement and several other

abnormalities are those mec.hanisms leading to the development of polyploidy

and thus to the differenti>dion of new taxa in Asteraceae (Femandes and

Leitao, 1984). Recent molecular and cladistic analysis has revealed that the

tribe Eupatorieae originated from the tribe Heliantheae (Ito et al. 2000). Based

on the available data from chromosomal and ntolecular phylogenetic studies of

the tribes Helinieae, Heliaitheae and Eupatorieae show that a polyploidization

polyploidization event occurred during ihe course of the divergence of the

tribe Helinieae and Heliantheae. Changing the chromosome base number and

the one of the polyploidy progeny was the ancestor of the tribe Eupatorieae

(Ito et al. 2000).

There are still enormous gaps in our knowledge as regards the cytological

evolution of Asteraceae, and much still remains to be done before a major

cytotaxonomic review may be attempted.

SUMMARY

Forty seven taxa representing a total of thirty four genera of Astcraceae are

studied for their detailed karyctmorphology. The chromosome spectrum of

Asteraceae ranges from 2n = 10 to 2n = 78 with majority of the species

concentrated in the number 2n == 18 followed by 2n = 24,2n = 36 and 2n = 40.

In spite of the wide range of chromosome numbers, there exist a relationship

between the different genera and species as evidenced by the frequent

occurrence of numerical variatton. This wide range of chromosome numbers

may be due to the difference in numbers in chromosome hiotypes belonging to

different groups. From the prt:vious literature and the present investigation it

is clear that many genera like Ageratum, Blumeu, Sphaeru~~hus. Cosmos and

Tagetes exhibit inter, intra and infra specific variations among chromosome

numbers. Presence of such widely different series of chromosome numbers in

the species of even same genus and in genera placed under different tribes and

subtribes, indicate that the difcerent chromosome numbers may be derived one

from other.

The basic chromosome numl~ers are found to be varied in Asteraceae. This

variability in the number of chromosomes at the basic level could possibly be

the result of aneuploidy at g.eneric level. Both primary and secondary base

numbers are found to be ~nvolved in the evolution of forty seven taxa

investigated. The primary base numbers (x 1) range from 5. 7. 9 and

secondary base numbers (x 2 ) range from 10, 1 1, 12, 13, 1 5, 16, 17 18 and 20.

The basic number x = 9 was found in majority of the numbers (30%) fbllowed

by the numbers x = 10, x = 12 and x = 11 with percentage 19. 17 and 13

respectively. The ancestral bzsic chromosome number of Asteraceae appears

to be x = 9.

In the present investigation 55.31 % are diploids and 44.68 % are polyploids.

Among the polyploids the majority are tetraploids. The various genera which

show a predominance of ployploidy include Adenostemma. Ageratum,

Chromolaena, Eupatorium, Cw~yzu, Blumeu, Bidens, Parthenium, Spilunthes

Tridau, Wedelia, Tagets, Cr~~socephalum and Notonia. The role of both

polyploidy and aneuploidy in the mechanism of speciation is obvious in

Asteraceae.

The computer aided image analysis system provides a better opportunity for

studying the various chromosomal parameters especially when the

chromosome size is very small. The method of using conventional numerical

parameters such as length and arm ratio are insufficient to distinguish the

chromosomes of many memlxrs of Asteraeace. By using image analysis

system it has become possible to obtain various kinds of quantitative data such

as length, area, perimeter and visual three-dimensional volume on the

chromosome images, idiogram can be prepared by using computer devices.

Hence this method would provide useful information for various

Karyomorphological analyses.

The general feature noted in the family Asteraceae is the wide range of

chromosome number with graded symmetrical karyotypes. However, the

chromosome complements in the members differ in minute karyotypic details.

With regard to gross morpholc~gy, chromosomes are nearly sub median to

nearly median in nature. The chromosome was found to range from 2.54 to

0.41pm in length. The total clromatin length shows a very wide variation

with 14.82 being the minimum and 90.32 being the maximum values. The

disparity index values were fout~d to range from 18.13 to 48.63 and the mean

centmmeric Index value (TF%) from 40.3 to 50.74. The coefficient of

variation ranges from13.94 to 35.97. .Thus the various micromorphological

details of the karyotype like, differences in absolute chromosome size,

difference in position of centromere, differences in total chromatin length

difference in karyotype formula and difference in the number as well as

position of the satellites, vary from cytotypes to cytotype. These variations

found in the karyotype parameters suggest that Asteraceae members are

characterized by symmetrical to slightly asymmetrical karyotypes. The

karyomorphological diversity found in the family shows that the group is still

undergoing active speciation.

The presence of a wide range 'of chromosome numbers, numerical variations

and structural changes of chromosome found in many genera mark the

significant role that both aneuploidy and polyploidy have played in evolution

of various taxa of the family a1 the generic and species level. The variability

in base numbers might have been resulted through protoautoploidy,

amphiploidy, ascending and descending dysploidy. Both mitotic and meiotic

aberrations have played a ma-or role in the evolutionary diversification of

family. Individuals with same chromosome number but with differences in

karyomorphological details reflect the ongoing evolutionary processes at

micro-level. It has also been found that in Asteraceae, Robertsonian changes

or mutations might have also played a major role in the evolution of

karyotype.

Documents

PART I CYTOLOGICAL STUDIES IN ASTERACEAEshodhganga.inflibnet.ac.in/bitstream/10603/6506/7/07_part 1.pdf · CYTOLOGICAL STUDIES IN ASTERACEAE . ... 1999). However, cytogenetic studies,