MORPHOLOGICAL AND ANATOMICAL STUDIES ON THE SEEDS OF SOME CROP PLANTS

DISSERTATION SUBMITTED

IN PARTIAL FULFILMENT OF THE REQUIREMENT

FOR THE DEGREE OF

MASTER OF PHILOSOPHY

IN

BOTANY

TARIQ OMAR SIDDIQI

DEPARTMENT OF BOTANY

AUGARH MUSLIM UNIVERSITY

ALIGARH

1978

JJNIVEB^

DSIO

# * * :<^-

V ,%^^

In the name of ALLAH, the b e n e f i c l e n t , the merc i fu l

He i t i s Who sendeth down water from the sky whence

ye have d r i n k , and whence are t r e e s on which ye senr

your beas t s to p a s t u r e .

Therewith He causeth,. Croj)S to grow for you, and the

o l i v e and the date-palm and grapes' and a l l kinds of

f r u i t . Lol here in i s indeed a p o r t e n t for people

who r e f l e c t .

Al Quran

dturah XVI, The 3ee

Dedicated to

"MY PARENTci"

CERTIFICATE

This i s to c e r t i f y t h a t t h e d i s s e r t a t i o n

e n t i t l e d " MORPHOLOGICAL AND iWATOKlGA^ dTuL'ibo ON

TiiE SEEDd OF t>OME CROP PLANTd " submit ted to the

Aligarh Muslim U n i v e r s i t y , Al igarh , i s a f a i t h f u l

r eco rd of the work c a r r i e d out by Mr. Tar iq Omar o idd iqu i

in p a r t i a l f u l f i l m e n t of the requirements for the svard

of the degree of Master of Phi losophy.

'^Jj/rr^J^a^^ ( M.I.R. KHAN j

Lec ture r Department of Botany

Aligarh Muslimi U n i v e r s i t y Al iga rh .

ACKNOV/LEDGEMEMT

I would l i k e to express my deep p e r s o n a l

a p p r e c i a t i o n to Dr. M.I.K. Khan for h i s i n c r e d i t a b l e

guidance and c o n s t r u c t i v e c r i t i c i s m . He so generous ly

gave h i s p rec ious time in checking the manuscr ip t .

I wish to express my s i n c e r e g r a t i t i j de t o

Dr. A.K.k. Ghouse for h i s va luab le advise and sugges t ions

on var ious a s p e c t s , and to Professor M.li.n.K. A f r i d i ,

Head, DepartmiOit of Botany, for p rovid ing neces sa ry

r e s e a r c h f a c i l i t i e s .

F i n a l l y I t a k e t h i s o p p o r t u n i t y t o acknowledge

the help ro ide red by , my Lab. co l l eagues Mrs. dhahnaz

Khan, Mr. Ahmad Hussain Khan, Miss oohee la Iqba l and

Mrs. Krishna Singh; my f r i ends Mr. Akhtar Haseeb, I r .

Akhter Hussain Khan, Mr. t iaisuddin Ahmad, Mr. nehanur

Rehman and Mr. Sarwat Hussain Anjum; and t h e t y p i s t

¥x. Zahoor Ahmad Khan.

November 1978 ( T A R I ' Q ' ' ^ A R aIDDi;UI )

C 0 NT E N T S

1. introduction . . . 1

2. Review of L i t e r a tu re . . . 8

3 . Plan of Study . . . 35

4 . Materials And Methods . . . 39

5. Appendix . . . 46

6. L i t e ra tu re Cited . . . 48

INTRODUCTION

" Seeds a re ever a P o s i t i v e and c r e a t i v e fo rce .

They are t h e germ of l i f e , a beginning and an end, the

f r u i t of y e s t e r d a y ' s harves t and t h e promise of

tomorrow's ", acccruing t o O r v i i i e L. Freeman (1961) ,

Boswell a l s o , i n 1961, very a p t l y remarked t h a t seed

i s a noun, an ad.fective and a v e r b . Watermen speak

of seed o y s t e r s , seed p e a r l s and seed f i s h . The o p t i c i a n

speeks of seeds i n g l a s s . The chemist seeds a s o l u t i o n

with a c r y s t a l t o induce c r y s t a l l i z a t i o n . We speak of

t h e seed of an i d e a or a p l an .

Above a l l e l s e , seeds are a way of s u r v i v a l of

t h e i r s p e c i e s . They a re a way by which embryonic l i f e

caJQ be almost suspended and then rev ived t o new develop­

ment;, even years a f t e r the p a r e n t s a re aead and gone

(Boswel l , i 9 6 i ) .

Seeds a re weal th . They ai-e beau ty . 'Iney are a

symbol - a symbol of beg inn ings . They a re c a r r i e r s of

a i d , of f r i e n d s h i p , of goodwi l l . They are ob j ec t s of

earnes t i n q u i r y i n man's c e a s e l e s s search for under-

s t ana ing of l i v i n g th ings (Boswel l , 1961) .

'i.

Committed for over a mi l l ion years t o a nomadic

l i f e , man se t t l ed down about 10,000 years ago when he

learnea t o sa t i s fy his hunger by growing food, especially

seed foods. Seeds, the great s tap le food of the world,

feed more people than does ai^ other type of food. The

endosperm or cotyledons with the i r rich food reserves

for the developing embryo and seedling offer man and I'

other animals a highly nutritious food that can be e a s i l y

stored (Ko2G.owski and Gunn, 1972).

The enlarged and matured ovule with i t s enclosed

embryo cons t i tu tes the seed (Eames and MacDaniels,i947).

In the mature seed following pai-i-s can be d ls t inguisned:

(a) the seed coat or t e s t a (Lat in - br ick or t i l e ) , the

chief functions of the seed coat are protect ion against

a t tack by microorganisms or i n s e c t s , mechanical injury

and desiccat ion and to help in dispersal (Bhatnagar and

Joh r i , 1972); (b) the endosperm (Greek - with i n and

seed), i t i s the storage t i s sue which provides nu t r i t i on

for the embryo and the young seedl ing. It may be present

i n variable amounts* (c) the embryo, i t cons t i tu t e s the

p a r t i a l l y developed young sporophyte (Esau, j.964).

In some seeds the enaosperm or per isperm,(nucel lar

t i s s u e p e r s i s t s ana increases in volume t o form the pe r i s -

perm, e .g . Beta) i s ccHnpletely absent and such seeds, as

well as those that contain a very small amount of endo­

sperm are termed exalbuminous seeds (Fahn, 1969), while

the seeds with endosperm or perisperm are cal led albumin­

ous - commonly found in monocotyledons (Esau, i964) .

The seeds of angiosperms vary widely i n s t ruc tu re

but are r e l a t i v e l y constant in nairowa' groups and, there

fo re , may be used in connection wit la taxonomic s tuaies

(McCiure, 195Y).

Variat ions i n seed s i z e , shape, colour and surface

are myriad and are important i n seed iden t i f i ca t ion .

Some species have l i t t l e seed v a r i a b i l i t y (Stenospermous),

whereas others have much v a r i a b i l i t y ( euryspermous;

Kozlowski and gunn, 1972). Some idea of the extent of

va r i a t ion in seefQ s i z e may be gained from the fact that

a aoubie coconut seea ana endocarp may have a fresh

weight of 20 l b , whereas 137 mi l l ion seeds of Ilysanthes

dubi^ weigh about 1 l b . Both l a rge and small seeds have

been considered pr imi t ive (Eames, 1961), Generally, large

seeds are associated with pe renn ia l , especial ly woody

p lan t s . Therefore, these seeds and plants are considered

pr imi t ive (Sal isbury, 1942).

Brown and brown der iva t ives are by far the most

conmon colcurs of seeds. Browns and blacks make up over

half of the seed co lours . Conspicuous colours sucn as

red, green, yellow anu white are in t requent . when x-hey

are present , they usua l ly have diagnoscic value(Koziowbkl

ana Gunn, i9r^i).

I'he surfaces of seed coats vary from highly

polished to markedly roughenea. iO.though tne surface

topogj-aphy has been used t o aavantage (Muriey, i 9 5 i ) ,

iu i s the appenaages which nave nacuraily drawn mos u

autention, Tnebe appendages include wings, a r i i a ,car­

uncles , sp ines , tuberc les , hairs ana eiaiosomea.

An ins igh t inves t iga t ion i n t o seed anauomy i s

providea by Martin ( i946) . KLs comprehensive stuuy was

basea on embryo type, s ize and placement; rooa reserve

quant i ty and quali ty anu seea s i z e . He orgaaizea the

seeds accox-dlng t o twelve embryo types.

Seed coats (Harz, 1885; Netoi i tzky, iyk:6; B.oingh

xyb4) , cotyieuons (Lubbock, l89ki; Martin, i94b; Bai ley,

x9fa6; Duke, 19D9) and enuospeitns (Brink anu Uooper, I9 4Y)

have been studied in d e t a i l ,

Ear le and Jones ( i962) compiled t ne r e su l t s or

chemical analyses for seeds from l l o p lants fami l ies .

The biochemical da ta are recorded unaer percent a sh ,o i l

and prote in; f ract ion of alcohol-soluble nitrogen and

t r i ch lo roace t i c acid-soluble ni t rogen; t e s t for alkaloid

s t a r ch , tannin e t c . In a supplement, Jones and Earle

(1966) tabulated o i l and pro te in content for seeat> oi

769 b p e c i e b .

Economic Importance; The food stored in seeds for the i r

early growth i s , a l so , food for people and animals.Wheat

i s the world's bread grain. Rice i s used almost en t i r e ly

as food and i s the main crop of southern AtJict. Sorghum

and mi l le t are s tap les i n par t s of China and Africa.

Corn i s pl)pular i n south Africa and Lat in America. Barley,

rye and oats also cont r ibute t o the worlds food supply

(bent i and Maclay, 1961).

Wine-tenths or a l l seeds cu l t iva ted are cereal

grains - the breadstuffs of the world. By far the greater

Part of the food of a l l the people i n the world consis ts

of seeds. Legume seeds are t he second great group of

seeds we use for food. All kinds of beans, peas and lent i l s

suppijr prouein . Some legumes, sucu as soybeans anu

peanuts are high i n o i l and p ro t e in , as are ce r t a in ooner

seeds, p a r t i c u l a r l y rape, sesame and sunflower. Peanuts

are the worlds second most important legume. They are used

mainly for their o i l . We produce peanut o i l , but t o a

much greater extent we eat the e n t i r e seed (Sentl and

Maclay, 1961).

All seeds probably contain some o i l , but t o make

the seed of commercial importance, quantity and character­

i s t i c s of the o i l are important. The commercial o i l seed

i s important, i n that there can be extracted from i t fat

or o i l , valuable i n human food and in industry for the

production of c onmodities such as paint and soap (Eckey,

1954) .

Chief among the oi l -bear ing seeds are f lax ,

ca s to r , tung (nuts from the China wood-oil t ree ) , p e r i l l a

(from an or ien ta l mint) and o i t i c i c a (from a Braz i l ian

t ree)» Seeds of soybean, cot ton, corn, rape and sesame

yie ld semidrylng o i l . Some are used i n paints along with

drying o i l s . Castor o i l , made from cas to r beans, has

gone out of s ty l e as a medicine. This non-drying o i l ,

however, i s now more in demand than ever before as a

f ine l u b r i c a n t , as a consti tuent of f lu ids for hyarau-

l i c a l l y operated equipment and as a source of chemicals

to make p l a s t i c s (Senti anu Maclay, l 9 6 i ) .

Solia fats from the seeds of the mahua t r e e , the

shea t r e e and the coconut palm are used to make candles

i n t ropical count r ies . The seeds of hard, fibrous ,stony

f ru i t s ca l led nu t s , provide highly concentrated foods,

7

o i l s and other materials of value. The Kernels of b raz i l

nu t s , casheirfS, coconuts, f i l b e r t s , hazelnuts , hickory

nu t s , pecant), walnuts ana pine nuts are preaominantly

oi ly and rich in p ro te in . Beverages are made from seeds

the world over. Coffee i s made frcoi the roasted and

ground seeds or the coffee t r ee . Cocoa, chocolate and

cocoa bu t te r come from the grounl seeds of the cacao

t r e e . D i s t i l l e r s use corn, malt , wheat, grain sorghum

and rye i n making beverage alcohol (Senti and Maclay,

1961).

The future i s br ight for greater uses of the

world's seed crops and for the development of new ones

with compositions and growth c h a r a c t e r i s t i c s that will

make them pro f i t ab le for the farmer to grow and for

industry to process (Senti and Maclay, 1961).

REVIEW OF LITERATURE

His tory : As e a r l y as 3000 years ago, t h e Arabs were

conscious of the r o l e of po l l en i n " d a t e " c u l t u r e . How­

ever , t h i s was almost forgot ten u n t i l the seven teen th

and e igh teen th c e n t u r i e s when Camerarius (1694) and

Koelrei i ter (1761-1766) e s t a b l i s h e d the r o l e of po l len

i n the format ion of s eeds . Amici (1824) d i scove red ,

for the f i r s t t ime, germinat ing Po l l en g ra ins on the

s t igma of P o r t u l a c a . S ix years l a t e r , he (Amici, 18cO)

t raced t h e p o l l e n tube t o t h e mouth of t h e ovule . Amici

(1847) and Hofmelster (1849) demonstrated t h e p resence

of a p r e e x i s t i n g germinal v e s i c l e (egg ' which, under

t h e s t i m u l a t i o n of t h e po l l en t u b e , gave r i s e t o the

embryo.

S t r a sbu rge r (1884) observed syngamy, which i s t h e

fus ion of one of t h e male gametes with the egg n u c l e u s .

For s e v e r a l y e a r s , t h e f a t e of t h e second male gamete

remained en igmat ic . In 1S98, Nawaschin showed tha t the

second male gamete fuses with t h e p o l a r n u c l e i , and t h i s

phenomenon I s r e f e r r e d t o as t r i p l e fus ion , Syngamy and

t r i p l e fusion t o g e t h e r c o n s t i t u t e double f e r t i l i z a t i o n

- a p rocess unique to angiosperms.

I n a d d i t i o n t o having m o r e - o r - l e s s showy appenda­

ges , t h e flower u s u a l l y has l e s s prominent or even hidden

sex o rgans . The sex organs comprise stamens and p i s t i l

and a re normally e s s e n t i a l for seed s e t . The stamens

c o n s t i t u t e uhe male or the p o l l e n producing p a r t s ; with

i n t n e po l l en g ra ins a re formea t n e sperms or male

gametes . Usually t h e p i b t i l , which i s the lemele or

seed forming organ , c o n s i s t s or t ne ovary , suy le and

s t igma, 'i'he ovai-y con ta ins ovu le s , t he p r o g e n i t o r s of

s e e a s . There are c e r t a i n r r u i t s which, even in n a t u r e ,

do not c o n t a i n s e e d s . Such f r u i t s are formed w^'thout

f e r t i l i z a t i o n and are r e f e r r e d t o as pa r thenoca rp ic

(Bhatnagar and J o h r i , 1972).

OVULE

The ovule or megasporangium i s t h e forerunner of

seed. A normal ovule has a s t a l k c a l l e d fun icu lus by

which i t i s a t t ached to the p l a c e n t a . The ovular envelopes

— the in teguments , enc lose a massive ( o r scanty) nucel lus

(Bhatnagar and J o h r i , 1972),

General ly f ive types of mature ovules have been

recognized . These are (a) o r tho t ropous or a t ropous ovu les ,

which occur i n Polygrnaceae , U r t i c a c e a e , c i s t a c e a e and

P ipe raceae , Here t h e micropyle and t h e funicu lus a re

founa i n the same l i n e (Bhatnagar and J o h r i , 1972); (b)

ana t ropous , a r e those type of ovules where t h e micropyle

10

and hilum are near each o ther , as a r e su l t of u n i l a t e r a l

growth. This type i s very common i n the angiosperms

(Dathan and Singh, 1970, 1^72, 1^/3 a,b; Taneja, li570;

Singh and Dathan, iy/'2 a,b; Pal , 1974); (c) In the

cajnpylotropous ovule the curvature i s much l e s s than the

anatropous type and this i s conmon i n Resedaceae and

Leguminosae; (d) In the amphitropous ovule the curvature

affects the nucellus and embryo sac, so tha t the l a t t e r

becomes horse shoe-shaped, as in some Alismaceae, BUT;O-

maceae ana Centrospermae (Bhatnagar and J o h r i , 1972);

(e) In the he mi anatropous or hanitropous type the funi­

culus i s at right angles to the nucellus and integuments

(Dathan and Singh, 1973 a ) . A pecul ia r type of ovule

found i n some members of Plumbaginaceae and Cactaceae

i s ca l led circinotropous (Bhatnagar and J o h r i , 1972).

Bocquet (1959) has discussed the morphology of

campylotropous ovules. He i s of the opinion tha t i t i s

important to consider the mode of development and vascular

supply to the ovule. According to him, the basic types

are orthotroPous and anatropous. During growth these

undergo curvature giving r i s e to the campylotropous

condit ion. Depending upon the ser ies t o whcih the ovule

belongs, the ovules are ca l led othroeampylotropous(caryo-

phyllaceae) i n the ortho s e r i e s , and anacampylotropouff

i n the ana s e r i e s , e .g . Leguminosae (Bhatnagar and Johri^

11

1972) , Cochlospermum Kinth. (Cochlospermaceae; Dathan

and Singh, 1972) and, Leoldlum sativum L. and Thlaspl

perfollatum L. (Cruciferae; Prasad, 1977). If the cur­

vature is much grea te r , the ovules are designated as

orthoampbitropous, as in Atriplex hor tensis or ana-

amphitropous as in Pisum sativum (Bhatnagar and Johr i ,

1972).

Davis (1966) has col lected information on ovule

morphology from 316 families of which 266 are d ico ty le -

aons. The morpnoiogy i s constant for ^48 fanailips ana

the anatropous condition i s represented in 204 famil ies .

Orthouropous ovules are met vl ohin k!0 families and

hemianatropous i n 13 famil ies .

Nucellus : Depending upon the extent of development of

the nucel lus , the ovule may be tenu inuce l la te or c rass i -

nuce l la te . In t he t e m i n u c e l l a t e ovule the archesporial

c e l l develops d i r e c t l y in to a megaspore mother c e l l . The

archesporial c e l l is surrounded by the epidermis only

( e . g . Cal ceo l^ r i a mexicana Benth; Tene;)a, 1970). The

de l imi ta t ion of c ras s inuce l l a t e ovules i s not at a l l

s a t i s fac to ry , jNormally, a c rass inuce l l a t e ovule i s one

where the archesporial c e l l cuts off a p a r i e t a l ce l l

12

a-fid i t s der ivat ives make the megaspore mother c e l l deep-

seated (Bhatnagar and J o h r i , 197k;). This type of ovule

i s found in Carlca candamarensis Hook. F, (Uathan and

bingh, 1970), i n Bixa L. am Cochlospermum fiinth. (uatnan

and Singh, l97ii) , i n GucurbitaQeae (Singh and Datban,

197kia,b) , i n Flacourt ia indie a (Burn, F. )Meri l l . (uathan

and Singh, 1973a), i n J'acsonia Juss . and Pas si f lo ra L.

(Uathan and Singh, 1973b), i n Cro^on oblongifoliusC^al,

1974) and i n Lepidium sativum L. and T hi as pi Perfoliatum

L. (Cruciferae; Prasad, 1977).

According to Davis (1966), i f the p a r i e t a l c e l l

i s not cut off, the ovule should be referred t o as ten-

u inuce l la te . The d i f f i cu l ty ar ises i n those cases where,

although a p a r i e t a l c e l l i s not formed, nucel lar c e l l s

surround the megaspore mother c a l l , e .g . in Anemone<

Aquilegia vulgar is (Bhandari, 1968; Bhandari and Vijaya-

raghavan, 1970), and Clematis gauriana (Vi jayaraghavan,

1962).

According to data co l lec ted by Davis ( I9b6) , tne

condition of nuceiius i s known ror 314 families of which

260 are d i c o t s . CrassinuceHate ovules are character­

i s t i c of 179 fami l ies , and tenuinucel iar ovules of 105

famaliea. eleven lamilietj possess pseudocrassinucel lar

I d

ovules. In tbe remaining 19 fajnilies, tne nucelius forms

a generic or specific charac ter .

Integuments : The ovules may be unitegmic or bitegmic.

In the former type, t he re i s a s ingle integument, where­

as in the l a t t e r there are two integuments, rne uni teg­

mic type of ovules are found in Calceolar ia mexicana

Benth. (Tane;5a, 1970); and bitegmic ovules are found i n

Garicg c^ndgmarensis Hook. F. (Dathan and Singh, 1970),

in seeds of Cucurbitgi (Singh and Dathan, 1972 a ,b ) , i n

Flacourt ia indica (Burn. F.) Mer r i l l . (Dathan and Singh,

1973 a ) , i n Tacsonia Jus s , and Pass i f lora L. (Dathan

and Singh, 1973 b ) , i n Croton obloneifolius (Pa l , 1974)

and i n Lepidium sativum L. and Thlaspi perfoliatum L.

(Cruciferae; Prasad, 1977).

The sympetalae are generally character ized by

unitegmic ovules while Polypetalae ana monocotyledons

generally possess bitegmic ovules. Another i n t e r e s t i n g

point i s the assoc ia t ion of unitegmic ovules with ten-

u inuce l la te condit ion and bitegmic ovules with crassinu-

c e l l a t e condit ion. In Ranunculaceae, Icacinaceae, Rosaceae

and Piperaceae, both uni - and bitegmic ovules occur,The

number of integuments has been useful for taxonomic

considerations ( Bhatnagar and J o h r i , 19'<'2).

14

I'he bitegmic condit ion has been considered primi­

t i v e and the unitegmic one derived. The l a t t e r condition

may r e su l t e i the r from fusion of the t>ro integuments, as

in some Lecythidaceae and Myrtaceae (Mauritzon, 1939) ,or

by suppression of one integument (Maheshwari, 1950).

Corner (1949) reported a middle integument in

some of the Annonaceae, namely, Canangium. Mezzettia and

Xylopia. The addi t ional integument arose as an i n t e r e s t

ary s t ruc tu re af ter f e r t i l i z a t i o n . Since an a r i l i s also

present i n these p l a n t s , the ovules possess lour i n t e ­

gument , The middle integument i n Cananga odorta shows

a s l i g h t l y d i f f e r en t behaviour i n tha t i t develops during

p r e f e r t i l i z a t i o n stages (Peri as amy and Swamy, 1961), A

rudimentary third integument has also been reported by

Vijayaraghavan (1964) in_S_arc_andra i rv ingba i l ey i .

The presence of stomata on the outer integument

has been reported in Cleome, Isomer is (Orr, 1921) , Nerine

cu rv i fo l l a (Sc hi i mba c h, 1924), Ar gem one mexicana( S ac h ar ,

1955) , Mich e l l a chafflpaca and Magnoli a s t e l l a ta (Paliwal

aM Bhandari, 1962). In Gossypium (Joshi et a l , , 1967),

Stomata d i f f e r e n t i a t e i n the outer integument at the

chalazal end. According to Ayyangar (1948), the stomata

are presumably associated vdth r e sp i r a t i on and production

of hairs on seeds.

15

In addition t o stomata, abundant chlorophyll is

present i n the integuments of Hymenocallis occidental is

( F l i n t and Moreland, 1943). I t has also been r p o r t e d

i n Amaryllis belladonna^ Brunsvieia minor (Hofmeister,

1861), Sobral ia micrantfaa (Treub, 1879) , Gladiolus

conmunis , Lilium mart aeon (Berg, 1898) and Moringa

o le i fe ra (Pur i , 1941). During p o s t f e r t i l i z a t i o n s tages ,

i n some members of GaesaLpinioideae, the outer integu­

ment develops chlorophyll and the ovule appears deep

green (Corner, 1961).

Some other s t ruc tu res are also associated with

oaules: (a) a r i l (MaheshwaTi, 1950; Eames, 1961; Kapil

and Vasi l , 196 3); (b) a r i l l o d e or caruncle (Eames, 1961)

and (c) Sarcotes ta .

Aril has been reported by Kaju (,i956) i n Pass i -

f loraceae, Kapii and Vaui (L963) reported i t i n Crosso-

soma Californicum, while Gamp and Hubbard (iy6ci) found

a r i l i n Paeonla and Vi jayaraghavan ana Kaur (i966)

reported the a r i l i n i'urnera. uimifoxia.

An a r i l l ode or cax'uncie i s a conmon feature or

Sapindaceae (van uer P i j i , L^t>7) and Euphorbiaceae

(Kapil , 1968).

16

b a r c o t e s t a i s t he fleshy or j u i c y o u t e r integument.

In MagnoHaceae i t con ta ins f a t and i s o i t e n colored(Van

d e r P i j l , 1955).

Abnormal qnd Reduced (Vules : The achene-bear ing genera

of Ranunculaceae u s u a l l y possess u n i o v u l a t e carpels.How­

ever , i n Adonis (Bhandar i , 1962, 1966) and Clematis

(Vi jayaraghavan, 1962) i n a d d i t i o n t o a f e r t i l e ovule ,

two t o four acessory s t e r i l e ovules a r e a l so p r e s e n t . In

Anemone o b t u s i l o b a (Bhandar i , 1968), bes ides t h e f e r t i l e

ovule , t h e r e are two marg ina l ly e longated " c y l i n d r i c a l

s t r u c t u r e s . " These r e p r e s e n t t h e s t e r i l e ovu le s . In some

fami l i e s of p a r a s i t i c p l a n t s the ovules a re not a t a l l

well def ined and t h e r e i s no demarca t ion between t h e

nuce l l u s and integument (Maheshwari e t a l . , 1957; J o h r i

and Bhatnagar , i960; H i i j t , 1969).

ENDOSPERM

The endosperm u s u a l l y develops a f t e r f e r t i l i z a t i o n

from t h e product of t r i p l e fu s ion , t h a t i s , t h e fus ion of

t h e two p o l a r n u c l e i with one male gamete (Br ink and

Cooper, 1947). In c e r t a i n p l a n t s , e . g . P i s urn. Phaseolus

and Arach is , t h e e n t i r e endosperm i s d i g e s t e d by the

developing ©nbryo . Gene ra l ly , i n t h e seeds of such

p l a n t s the co ty ledons th i cken ana they s t0i .e r e s e r v e

17

substances which provide m t r i e n t s for the young seed­

l i n g s . In other p l a n t s , e.g. Ricinus and plants belong­

ing t o the Graminae the endosperm functions as a s torage

t i s s u e . In the former type mainly s tarch grains and

proteins are the stored substances. In Ricinus, however,

aleurone grains occur throughout the en t i r e endosperm.

In endosperm, i n which there i s no s t a rch , o i l s and fats

may be present as reserve substances (Fahn, 1969).

Cell walls that cons t i t u t e reserve ma te r i a l , e.g.

i n the seeds of Phoenix and Diospyros, usua l ly consist

of hemicellulOSes and other s imilar carbohydrates. In

Phoenix, Meier (1958) recorded tha t these walls contain

about 6Jg of c e l l - u l o s e . These ce l l s have a very thick

secondary wall .

Some seeds, e .g. those of Ceratoni^ have a mucila­

ginous endosperm, A s t r a t i f i e d thickening of the walls

of these endospermal ce l l s are hard and, during germina­

t i o n , they function both as a swelling and n u t r i t i o n a l

t i s s u e (Netol i tzky, 1926).

The endosperms resu l t ing from the three methods

of development are c a l l ed , (1) nuclear or, more appro­

p r i a t e l y non-cel lu lar (Kao, 1959); i'd) Ce l lu la r , and(3)

helobial ( a f t e r Helobiae, a monocotyledonous taxon).

18

1, Nuc l^^ or Non-cellular Endosperm : In the Nuclear-

type development the primary endosperm nucleus undergoes

a se r i e s of free-nuclear d iv i s ions , which may be synchro­

nous or non-synchronous. When many nuclei have been form­

ed, they arrange themselves per iphera l ly in a layer of

cytoplasm. La te r , c e n t r i p e t a l wall formation takes place

(Bhatnagar and J o h r i , 19/2).

Wall formation does not occur i n plants such as

Oxyspora (tJubramanyam, l951) , Limnanthes (Mathur, 1956),

Cg^rlca (Pat nan and Singh, 19Y0), Amischophacelius

Chikkannaiah, 1973), F lacour t ia (Ilatnan and Singh,1973a)

and, Tacsonia and Pas si f lo ra (Dathan and Singh, 1973b).

In Several fami l ies , wall formation i s l imited only t o

the upper and middle region of t he embroyo sac so the

chalazal region remains free-nuclear . This region often

elongates and functions as haustorium (Bhatnagar and

Joh r i , 1972). It was through the technique of dissected

whole mounts that Kausik (1941) discovered, for the f i r s t

t ime, a "vermiform appendage" i n the endosperm of Grevi-

l l e a robust a. The lower portion of the haustorium in

Mimosa pudica (Johri and Garg, i959) forms several proce­

sses wnich enter the nucel lus; the haustorium i s coiled

i n Cal l iandra (Dnyansagar, 1958), In Cyamopsis ftsoralio-

ides and Desmodium pule helium (Rau, 1963), the haustorium

eventually becomes c e l l u l a r .

19

In Croton oblongifoilus (Pa l , 1974) , Trltlcum

aestivum (Mares et a l , , l975), Eraerost ls unlololdes

(Deshpande, 1976) and Jubaeopsis c ^ f r ^ (Robertson, 1976)

the endosperm ab i n i t i o i s f ree-nuclear , but i n the

mature seed i t i s c e l l u l a r .

The endosperm of coconut (Cocos nuclfera) i s

very i n t e r e s t i n g , when the f ru i t s are 50 mm. long, the

embryo sac i s f i l l e d with a watery f l u id , a l so cal led

milk. The l a tue r nas numerous free nuclei and cytopla­

smic p a r t i c l e s , and i s referred t o as l iqu id syncytium.

The ploidy of the nuclei in the syncytium varies from

2n t o iDn (Dutt , 1953).

2. Cel lular Endosperm : The Cel lular endospei-m i s

cnaracter ized by absence of a free-nuclear phase, and

a iv is ion oi the primary endosperm nucleus ana subsequent

divisions are invar iably followea by wail iormation,e, g.

S ol anum mac rant hum (Mohan, 1970) and Calceolar ia mpxi-

cana (Tane;)a, 1970).

The haustoria may develijp at the micropylar or

cha laza l end, or both. A micropylar haustorlum i s pro­

duced in Imp a t ! ens royl^i (JJahlgren, l934) and ri yd roc era

t r l f l o r a (Venkateswarlu and Lakshminarayana, 1957),KaPil

20

and Bhandari (1964) reported a two-celled chalazal endo­

sperm haustorium in Magnolia ovata.

The development of endosperm in KLugia notoniana

(Gesneriaceae) i s very unusual (Arekal, 1961). Both

micropylar and chalazal haustoria are organized. Taneja

(1970) also reported this type of endosperm i n Calceol­

a r i a mexicana.

3 . Helobial Endosperm : The Helobial Endosperm in

angiosperms has been reviewed by Swamy aixl Parameswaran

(1963). The primary endosperm nucleus divides and two un­

equal chambers are formed, t:he micro pylar one being larg­

er than the chalazal one. In the micropyiar chamber,seve­

ra l i ree-nuciear a iv is ions take place but , u l t ima te ly ,

iu becomes c e l l u l a r .

In Phylidrum lanuginosum (Kapil and Wall a, 1965),

t he chalazal chamber frequently divides e a r l i e r than the

micropyiar chamber; the d iv i s ion may be followed by wall

formation.

Ruminate Endosperm ; Sometimes the endosperm may be

unevern or i r r e g u l a r and i s referred t o as ruminate. It

can not be classed as a separate type of endosperm as

was done by L ins kens (1969) because rumination does not

s t a r t in the i n i t i a l stages of development. I t i s tne

21

ul t imate i r r egu la r shaPe that may be due to the uneven

inner surface of the t e s t a . Rumination i s caused by-

a c t i v i t y of e i ther the seed coat or the endosperm.

Periasamy (1962) has d is t inguished , on a morpho­

l o g i c a l b a s i s , seven types of rumination. These are

present i n the following genera: Passiflora.. Verbascum,

^nnona, Myrist ica, Coccoloba, Spigel l^ and iiilytrarla.

JSMBRYO

In 1837, Schleidan published de ta i led observa­

t ions on the or igin and development of the ovule. He

confirmed Amici's (1824) statoEent tha t the Pollen tubes

make t h e i r way from the stigma to the oaule, entering

the l a t t e r through the micropyle. His l i v e l y imagination

carr ied him too far , however, for he asserted tnat the

extremity of the pollen tube pushes the membrane of the

embryo sac before i t and d i rec t ly becomes the embryonal

ves ic le which then unaergoes a number of d ivis ions to

produce the embryo.

Embryo shows a va r ie ty of developmental oat terns

and a t t a ins different sizes and degrees of d i f i e r e n t i a -

t ion. Conmonly the future vegeta t ive organs of the p lant

are i n i t i a t e d during the development of the embryo, at

22

l e a s t i n the form of the i r apical meristems. The embryo

cons i s t s of an axis , the hypocotyl-root axis , bear ing,

at one end, the root meristem and, a t the o ther , the

cotyledon or cotyledons and the meristem of the f i r s t

shoot. Sometimes a shoot bud, the epicotyl and a prim­

ordia l root , the rad ica l ) are present i n the embryo

(Esau, 1964). In the peanut (Arachis hypogaea) , the

embryo has not only a leafy epicotyl but a lso two l a t e r a l

shoot primordia a r i s ing in the cotyledonary axils

(Yarb rough, 1967).

The grass family has a highly d i f f e ren t i a t ed

embryo with many p a r t s , including adventi t ious root

primordia. Some dicotyledonous embryos a lso have such

primordia (Steffen, 1952). On the other hand, an embryo

may be poorly d i f f e r en t i a t ed , even lack cotyledons

(Cis ts^nche^ a pa ras i t i c herb; Kadry, 1956). A procambial

system, continuous throughout the hypocotyl and the

cotyledons, i s coranonly d i f fe ren t ia ted i n the embryo.

Some vascular elements may mature in an embryo before

the seed germinates (Esau, 1964).

The development of an embryo follows an orderly

pat tern cha rac t e r i s t i c of a given plant group from the

outse t . The d i f f e ren t i a t ion in to a root pole and a shoot

pole ind ica tes an early establishment of po la r i ty

23

(Wardlaw, 1955), and the difference between the two poles

increases through d i f f e r en t i a l divis ions and ce l l enlarge

ment in the successive stages of embryogeny (Meyer, 1958).

The behaviour of embryos cul tured in v i t r o

suggests that the embryonic form re su l t s from an i n t e r ­

act ion between the embryo and environmental factors with

in the ovule, such as n u t r i t i o n , space and others

(Norstog, 1961).

The pa r t of the embryo derived from each t i e r of

the four-cel led embryo may differ from genus to genus

or from species to species , but they may a l so vary with

i n the same species (Bhaduri, 1936; BorthwicR, 1931),

and they do not determine the l a t e r his togenesis i n the

embryo (Guttenberg, I960), Despite these l i m i t a t i o n s ,

the cha rac t e r i s t i c s of embryos i n t h e i r early develop­

mental stages are given much weight i n comparative

s tudies (Yakovlev, 1958; Johansen, 1950; Soueges, I9ct8,

1939, 1948, 1951). Several types of ear ly embryo ontog-

enies have been cone lev ed, chief ly by Soueges (Summary

of types in Guttenberg, I960). In 1951, Yakovlev publish­

ed his observations on the develt^ment of the embryo in

Paeonia, which i s unique and unknown i n angiosperms. The

d iv i s ion of the zygote nucleus ana subsequent d iv is ion

24

of daughter nuclei are not accompanied by wall formation

resul t ing i n a coenocytic s t r u c t u r e . Yakovlev and Yoffe

(195V, l y o i , I9t)6) descrlbea \.vo pnases i n ztie embryo-

genesis of Paeonia. In the f i r s t phase, a coenocytic

s t ruc ture i s formed, and the nuclei become delimited by

wails . In the second phase, a few ^b ryona l primoraia

d i f f e ren t i a t e per ipheral ly and give r i se to embryos. How­

ever, only one embryo a t ta ins maturity and i s t yp i ca l l y

dicotyledonous (Yakovlev, 1969), This observation has

been confirmed by Gave et a l , , ( l 9 6 l ) , Carniel (1967),

Matthiessen (1962) and Moskov (1964) in various species

of Paeonia.

Murgai (1959, 1962), who a l s o studied several

species of Paeonia does not agree witn the findings of

Yakovlev and Yoffe. She observed a t ransverse v a i l , a f t e r

d iv i s ion of the zygote, separating a smaller apical and

a much la rger basal c e l l . The basal c e l l becomes coeno­

cytic where as the terminal c e l l divides v e r t i c a l l y .

Further development of the apical t i e r i s delayed u n t i l

c e l l formation occurs in the basal c e l l . During l a t e r

s t ages , according to Murgai, i t i s d i f f i c u l t to ascer ta in

the der iva t ives of the apical and basal c e l l s , but the

development of the embryo conflrns t o the observations

of Yakovlev and Yoffe.

26

Normally, the mature embryo cons i s t s of a r a d i c l e ,

a plumule and one or two cotyledons. However, i n some

plants the embryos are reduced and lack d i f f e ren t i a t ion

in to organs. The coiled embryo of Cu£cut^ shows a shoot

apex but i s devoid of the cotyledons and rad ic le . In

Orobanchaceae (Tiagi , ]951, 1963, ]965; Rangan and Ranga-

swamy, 1968), a family of toteil root p a r a s i t e s , the

embryo lacks a radicGe, hypocotyl, cotyledon, epjrocyl ana

plumule. The embryos of Orchidaceae are minute and un­

d i f fe ren t i a ted (wLthner, 1959; A r d i t t i , 1967; Poddubnaya-

Arnoldl, 1967).

In several other famil ies , such as Balanophoraceae,

Hydnoraceae, Lent ibular iaceae , Pandanaceae, Pyrolaceae,

Rafflesiaceae and Xyridaceae, the embryos lack differen­

t i a t i o n of t i s sues and organs or both (Rang as wamy, 1967).

In several p lants the suspensor of the embryos

exhibit great var ia t ion with regard to i t s si^^e, shape

and number of c e l l s . In Orchidaceae i t s e l f there i s

great d i v e r s i t y (Swamy, 1949). In Cypripeaium. the

suspensor is s ingle - c e l l e d sac l i k e , conical or tubular

The suspensor in Ophrys cons is t s of five t o ten ce l l s

which grow beyond the micropyle. On reaching the placenta ,

the suspensor sends out haustor ia l branches. In ii>pj.den-

drum, the c e l l s of the suspensor look l i k e a bunch of

26

grapes. In Vanda^ the ce l l s elongate downward and

envelope more than half of the embryo. In Dendrobium^

the suspensor forms a much-branched haustorium (Podd-

ubnaya - Amordi, 1967). In Alblzzia lebbek, the embryo

lacks suspensor and is embedded In the endosperm(Pillai

et al.^ ]974).

A var ie ty of modifications of the suspensor

are knovn i n Leguminosae (Maheshwari, 1950). It may

consist of a rcw of several c e l l s which may be binucl-

eate ; sometimes the cel ls are la rge and coenocytlc. In

Cytisus the c e l l s appear as a bunch of grape.

In Podostemaceae also there may be a s ingle

la rge coenocytic haus tor ia l c e l l as i n Indo t r i s t i cha

(Mufeada, 1963); or several t hin-wailed haus tor ia l

branches may grew i n between the integuments e.g. i n

Dicraea (MuKcada, 1962).

Suspensor haustoria have also been reported i n

Rubiaceae, Halorrhagaceae, PUmariaceae and Crassulaceae.

Loranthaceae, perhaps, show the longest suspensor in

angiosperms (Bhatnagar and J o h r i , 1972).

The evolutionary signifacance of these types has

not been ful ly es tabl ished (Takhtajan , 1969) but they

'^l

have been u t i l i z e d for taxonomic purposes (Crete , 1956;

Leb"bgue, 1952; Soueges, 1966), The s t ruc tu re of the

mature embryo and i t s pos i t ion i n t h e seed and r e l a t i on

to t he endosperm also are d i s t i nc t i ve i n different

groups of plants ana thus may serve for i a e n t i t l i n g

seeds (Martin, 1946). Mature onbryo c h a r a c t e r i s t i c s

play an important ro le in the c l a s s i f i c a t i o n oi Graminae

(Reeaer, 1957).

Dicotyledon and Monocotyledon Jiambryos; The number of

cotyledons - one i n monocot-yleaons, two i n dicotyledons

i s considered to be tne primary d i s t i n c t i o n between the

two groups of angiosperms, but ce r t a in dicotyledons

normally develop a s ingle cotyledon (Haccius, I95i^ a;

Takhtajan, 1959). There are also dicotyledons wL th more

than two cotyledons (Haskel l , 1964). The ontogenetic

fusion of cotyledonarv sheaths i s another s t r ik ing devia­

t ion found i n some di:«)tyledons (Haccius, 1953).

Embryos of dicotyledons and monocotyledons may be

similar i n form up to the s tage when the main body of t he

embryo i s globose i n shape. Subsequently, the d ico ty le ­

donous embryo assumes a bilobed shape, because of the

appeajcnace of the two cotyledons, whereas the monocotyle-

donous embryo i s changed i n to a more or l ess cy l indr ica l

28

s t ruc tu re by the extension of the s ing le cotyledon. The

cotyledons of the dictyledonous embryo a r i se two meris-

tematic protrusions on the apical end of the embryo.

This change in shape r e s u l t s from loca l ized growth based

on pe r i c l ina l divisions in the two opposite posi t ions i n

the embryo where t he cotyledons l a t e r appear. The p e r i ­

c l i n a l d iv i s ions occur i n severa l supe r f i c i a l layers

which may include the outermost l aye r (Miller and Wetmore,

1946; Nast, 1941).

The re la t ion of the s ingle cotyledon of monocoty­

ledons t o the apex of the embryo is a mati;er of contro­

versy. According to one view, the cotyledon is terminal

i n o r ig in , the shoot apex i s l a t e r a l and the whole p lant

i s a sympoaium of l a t e r a l shoots (boueges, l954). Other

s c i e n t i s t s consider the terminal pos i t ion of the cotyle­

don to be only apparent: the l a t e r a l pos i t ion of the

apical meristem resu l t s from i t s displacement by the cot­

yledon (Baude, 1956; tlaccius, iisSSb; bwamy and Lakshmanan

19bii). In the dictyledons having a s ingle cotyledon the

embryogenetic events resemble those i n monocotyledons and

support the idea of the i n i t i a l l y l a t e r a l or igin of the

cotyledon (Haccius, 1964).

iiJiibryos in various stages of a l f f e r e n t i a t i o n may

contain chloroplas ts (Podaubanaya - Arnoldi , 1352).

i i 9

Chemical analyses and exper imenta l s t u d i e s with l i g h t

i n d i c a t e t h a t t h e c h l o r o p l a s t s a re p h o t o s y m h e t i c a l l y

a c t i v e and t h a t the pigmenu may be c h l o r o p h y l l (i<>^ntor,

iy66; Meeuse and Ott , i9b i i ) .

The e a r l y embryogeny i s t r e a t e d comprehensively

i n t h e b o t a n i c a l l i t e r a t u r e ( Johansen , lySO; bchnarf ,

1929, 1931; bwamy and Faumanabhan, 1962), S tud ies on

t h e l a t e r embryogeny, p a r t i c u l a r l y those concerned with

t h e o rgan i2a t ion of the system of primary meristems

( p r o c o d e r m pro cambium and ground meristem) and of t h e

a p i c a l meristem a r e , on the c o n t r a r y , r a t h e r l i m i t e d i n

number (Arno t t , 1962; B i e l l , 1E>5^; Mi l l e r and Wecmore,

1946; Nasu, 1941; Reeve, 1948).

SEED COAT Oti TEST A

During t h e ma tu ra t ion of s e e d , t h e t e s t a u n i e r -

goes var ied . degrees of s t r u c t u r a l a l t e r a t i o n . There

may be a change i n con ten t s and wall s t r u c t u r e as wel l

as d e s t i u c t i o n of some or a l l of t he o r i g i n a l integumen­

t a r y l a y e r s ( N e t o l i t z k y , 1926). De ta i l ed s t u d i e s have

been c a r r i e d ouu i n Acanthaceae, Cucurbit aceae , Euph-

o r b i a c e a e , Leguminosae, Malvaceae ana some o the r families

(B. Singh, 3964) .

30

In the mature seed of the Umbelliferae only the

outer epidermis of the outer integument remains. In the

seeds of cer ta in genera of the Coa|)Ositae, e .g . Lg-Ctuca.

the integuments are represented oriLy by a th in layer of

ob l i t e ra ted c e l l s . In seeds developing from ovules with

two integuments, the two integuments may be present i n

the t e s t a or only two or three of the outer-most layers

of the outer integument may remain. In such seeds the

inner integament may c o n s t i t u t e the major port ion of the

seed coa t , or the outer one may be the b e t t e r developed

and be especia l ly adapted for p ro tec t ion v^i ie the inner

i s non-special ized. The former type i f cha rac t e r i s t i c of

Hypericaceae, Malvaceae, T i l i aceae and Violaceae; and

the l a t t e r of the BaTbericiaceae, Cruciferae, Papaveraceae

and ce r t a in genera of the Araceae, Ir ldaceae and L i l i a -

ceae (Fahn, 1969).

There may be var ia t ions in the i n t e n s i t y of cel lu­

l a r des t ruc t ion ; in the degree of s c l e r i f i c a t i o n and the

d i s t r i b u t i o n of mechanical c e l l s ; i n the deposition of

colouring and other organic substances; and i n the differ­

ent ia t ion of specia l ized trichomes, such as ha i r s , p i p i -

l l a e and hooks (Esau, I960). In some Cucurbitaceae the

hard outer part of the seed coat separates from the inner

papery l a y e r s , which remain attached t o the embryo to-

31

gether with the remains of the nucellus and endosperm,

(B. Singh, 1953). In the Leguminosae, the protodermal

ce l l s elongate at right angles to the surface and

d i f f e r e n t i a t e i n to macrosclereids (Corner, i36 i ; Keeve,

l9 46 a , b ) . The seeds of Leguminosae a t t r a c t considerable

a t ten t ion because of the peculiar wall formation, the

l i g h t l i n e , i n the outer epidermis of the t e s t a . The

^ ide rmis forms the pal i sade layer cons is t ing of sc le r -

eids (Ste iner and Janke, 1965). The l i g h t l i n e , which

occurs somewhat above the middle of the c e l l s , is a

pa r t i cu l a r l y coiqpact wall region, more t ransparent and

more highly doubly r e f r ac t i ve than the res t of the

wall (Frey-wyssling, 1969). In Cereidium the l igh t l i n e

was found to have a t ransverse o r ien ta t ion of micro -

f i b r i l s in contras t vdth the dominantly p a r a l l e l , longi­

tudinal o r ien ta t ion elsewhere in the wal l (Scott et a l . ,

1962). The l i g h t l i n e i s commoitLy in te rpre ted as playing

a ro le in the impermeability of the t e s t a , especial ly in

the hard legume seeds , but the exact nature of imperm­

e a b i l i t y of th is l i n e i s not known (Frey-Wyssling, 1969).

The Structure of the seed coat i s well understood

i f studied developmentally. The development may be c lass i ­

fied i n t o two types : (1) Seed coat derived from an ovule

with two integuments; and (ki) Heed coat derived from an

32

ovule with a s ingle integument.

(1) : In co t ton , which has a bitegmic ovule, both i n t e ­

guments cont r ibute towards formation of the seed coat

(Ramchandani et a l . , 1966; Joshi et a l . , 1967). In

Amischophacellus a x i l l a r i s L. , the seed coat i s formed

by both the layers of the inner integument and the inner

epidermis of the outer integument. Tne c e l l s of the outer

layer of the outer iniBgument i n uhe c o l l a r region form

a cap crowning the seed (Chikkannaiah, 197cs). In Garica

candamarensis Hook.F. , the seed coat i s formed by both

integuments and con^jrises seven zones : s a r c o t e s t a ,

outer ana inner zones of endotesta , c r y s t a l l aye r , main

sclerenchymatous layer - outer epidermis of the inner

integument, parenchymatous layers and the tanniferrous

l ayer (iiathan and Singh, 1970). The seed coat of Bixa L.

and Cochlospermum Kunth. , develops from both tne integu­

ments and comprises eight and s i x zones respec t ive ly a t

maturi ty. The main sclerenchymatous layer i s formed by

the outer epidermis of the inner integument and the outer

parenchyma possess dye ce l l s i n Bix^ whereas gum cav i t i e s

occur in the inner parenchyma of Cqchlospermum (Dathan

and Singh, 1972), In F lacour t ia i nd i ca , the seed caat

i n formed by both the integuments am comprises the lollow-

ing f ive zones : seed epidermis, 2-layered sclerenchymatous

33

hypodermis, narrow taJ^gentially elongated s c l e r e l d s , a

thin-walled parenchymatous layer ana the inner tanni -

ferrous layer (Dathan and Singh, 1973a). The seed coat

of T^csonia mollissima Juss . i s formed by both T;ne in te ­

guments with seven or e ight l a y e r s , while i n Pass i t l o ra

caerul^^ L. ana P. edulis.. the seed coa t , developing

from both t h e integuments, shows only six layers (Dathan

and Singh, 1973b). Seed coat of Groton oblongifolius i s

also derived from both the integuments (Pa l , 1974). In

1977, Prasad found that seed coat of Lepidjum sativum L.

and Thlaspi perfoliatum L. (Cruci ferae) , although,

develops from both the integuments, but cons is t s of ordy

two layers : a t h i c k mucilaginous epidermis ani a mechani­

cal l ayer .

(2) : DeveLopment of tne seed coat i n (Jucurbitaceae

a l so presents some i n t e r e s t i n g features (B. Singh,1962,

1953; D. Singh, 1961, 1964, 1965, 1967; Singh and Dathan,

1972 a ,b) . The ovule is bitegmic, but only the outer

integument takes part i n the development of seed coat ,

and the inner integument degenerates. The mature ^ed coat

i s d i f fe ren t ia ted in to five zones? (a) Seed epidermis

consist ing of cells rad ia l ly or t an gen t i a l l y elongated,

homogeneous or heterogeneous, thin-walled or with rod­

l i k e , tubular, s p i r a l , or r e t i c u l a t e thickenings on the

34

radia l walls; (b) hypodermis i s one-to m«i7-layered with

uniform or s inuate and thin or thick-walled c e l l s ; (c)

main sclerenchymatous layer comprising brachy 3 t e o - , or

branched types of s c l e r e ld s ; (d) aerenchyma ler lved from

hypodermis, ccmprising s t e l l a t e c e l l s that have prominent

air spaces; and (e) chlorenchyma of t h i n walled ce l l s

formed from the remaining layers of integument.

The development of seed coa t , only from the outer

integument, is also found in Acacia n i l o t i c a (Sinha,197a)

and Albizzia lebbek Linn. ( P i l l a i et a l . , 1974).

In Acanthaceae, which possess unitegmic ovules,

the massive integument is consumed by the developing

endosperm and only the epidermis pp r s i s t s i n the mature

seed (Wadhi, 1970). The seed epidermis develops various

types of hairs or thickenings (Bhatnagar and Pur i , l970) .

E ly t r a r i a (Johri and Singh, 1959), Andrograohis (Mohan

Ram, 1960; Mohan Ram and Masand, 1962), and Haplanthus

(Phatak and Ambegaokar, 1961) are devoid of seed coat at

matur i ty , and the outer layers of endosperm take up the

functions of the seed coat .

PLAN OF STUDY

The vd-de use of seeds i n haman food and animal

f eeds tu f f s has made knowledge of t h e i r anatomy of para­

mount importance. I t i s e s s e n t i a l t o be able t o i d e n t i f y

fragments of seeds i n r e l a t i o n to p o s s i b l e a d u l t e r a t i o n

and p u r i t y .

Although many s p e c i e s have been s t ud i ed for seed

s t m c t u r e , r e l a t i v e l y few f a m i l i e s have been c a r e f u l l y

s tud i ed s y s t e m a t i c a l l y and i n d e t a i l , fol lowed by docu­

menta t ion of the r e s u l t s .

Enough i s known for us to r e a l i z e t h a t compara^

t i v e s t u d i e s of seed can y i e ld taxonomic c h a r a c t e r s of

some s i g n i f i c a n c e , undoubtedly , as more fami l ies a re

s y s t e m a t i c a l l y s t u d i e d , much of taxonomic and perhaps

phylogenet ic i i ^ o r t a n c e w i l l emerge.

Keeping i n view of the above, t h e p re sen t

problem, "morphological and anatomical s t r u c t u r e s of

seeds of some crop p l a n t s , " i s s e l e c t e d for an in t ens ive

s tudy .

The p resen t work s h a l l i n c l u d e the fo l lowing

aspec t s J

A. Macroscopic S t r u c t u r e

B. Microscopic S t r u c t u r e

36

( i ) Pericarp

( i i ) Seed coat or Testa

( i i i ) Endosperm

(iv) Mature Embryo

C. Histochemical s tudies of tbe mature seed

D. Class i f ica t ion of seeds

A. MACROSCOPIC STRUCTURE : For describing the morpho­

logy of seed, i t is important t o consider the following

characters :

( i ) The posi t ion of seed i n the f r u i t , that i s ,

i t s attachment to the funiculus;

(ij) Whether tbe seed i s e r ec t , reversed, or

horizontal?

( i i i ) the colour of seed;

( iv) whether the surface of the seed i s smooth,

wrinkled, ribbed, puncta te , r e t i c u l a t e ,

glabro'us , pulpy or have markings resembling

finger p r i n t s ;

(v) whether the seed coat is hard or so f t ;

(vi) whether the hairs or t r i e homes are present

or absent on the seed; and

( v i i ) shape of the seed.

B. MICROSCOPIC STRUCTURE : For the microscopic study of

seed, d i f fe ren t methods wi l l be employed for different par ts ,

37

( i ) Pericarp '• Two standard techniques wi l l be enployed

i n order t o prepare s l ides for the study, tha t i s ,

paraffln-waX embedding procedure (Johansen, 1940)

and maceration process (Ghouse and Yunus , 1972;

Ghouse e t a l . , 1974).

( i i ) SeQd Gog.t or Testa : For the study oi t e s t a , seeds

will be sectioned by the Reicher t ' s s l i a ing micro­

tome with the seed held between two pieces of cork,

balsa wood, or polysterene. If the seed i s very

smaii i t wi l l be cut by the Rotary microtome follow­

ing the normal paraf f in embedding method (Johansen,

1940), 'I'esta wi l l also be studied by the maceration

process (Ghouse and Yunus, 1972; Ghouse et a l . ,1974)

and pe€ling process .

( i i i ) Endosperm : Endosperm will be s tudied following the

method described by Kadley (1977).

(iv) Mature Ehibryo : Embryo wi l l also be studied follow­

ing the sect ioning by Reicher t ' s s l id ing microtome

with the Seed held between two pieces of cork ,ba lsa

wood, or polysterene. If t he seed i s very small , i t

wil l be cut by the Rotary microtome following the

normal paraff in embedding method (Johansen,1940).

38

G. HISTOCHEMICAL STUDIES OF THE MATUKE SEED; Seeds of

t h e s e l e c t e d crop p l a n t s v l l l be tatcen and cu t by Re iche r t s

s l i d i n g BBlcrotome, The s e c t i o n s w i l l be s t a i n e d i n d i f f e r e n t

chemicals for i t s h i s tochemis t ry (Vaugban, 1970) .

D. GLASSIFICATIOW OF SEEDS ; Comparative s t u d i e s of seeds

of s e l e c t e d crop p l an t s may y i e l d taxonomic c h a r a c t e r s

which may be of some s i g n i f i c a n c e .

A dichotomous key wi l l be p repa red t o c l a s s i f y

the seeds on t h e bas i s of o b s e r v a t i o n s .

MiffERlALS AND METHODS

The seeds of the s e l e c t e d crop p l a n t s w i l l be 1

c o l l e c t e d and f ixed i n F , A . A, The seeds w i l l be allowed

t o remain i n t h e f i x a t i v e for about a week and then wi l l 2

be t r a n s f e r r e d to 70% e thanol or a l c o - g l y c e r o l mixture

Sec t ion ing of t h e Seed :

The f ixed m a t e r i a l w i l l be washed thoroughly i n

running water be fore s e c t i o n i n g . The s e c t i o n i n g w i l l be

done i n t r a n s v e r s e p lane on Beichert 's s l i d i n g microtome

at a th ickness of 1 0 - 1 2 / 1 . In c a s e , i t i s not p o s s i b l e

t o cut seeds i n dry s t a t e , they w i l l be sof tened by

soaking i n water or i n 5-20J& hydrof lour ie ac id . The acid

soaked seeds w i l l be washed i n running water for 24 hours,

I f t h e seedsa re very small i t w i l l be cut by t h e

Hotary microtome, fol lowing the p a r a f f i n embedding proce­

dure (Johansen, 1940).

To s tudy the p e r i c a r p , seed coat and mature

embryo s e r i a l s e c t i o n s w i l l be p r epa red out of m a t e r i a l s .

1,2. See Appendix.

40

Paraff in Method;

The fixed mater ial will be washed thoroughly i n

running water. The next step i s to remove water from the

t i s s u e s .

Dehydration : i'o remove the water from the t i s s u e s , de­

hydration will be done with the t e r t i a r y butyl alcohol

method (Johansen, 1940).

The dehydration process wi l l commence from 5%

ethyle alcohol i n d i s t i l l e d water , followed by i l , 18,

30, 50, 70, 95 and K)0% ethyl a lcohol . Following the

100% solu t ion , there will be th ree changes of pure t e r t i ­

ary butj^ alcohol , by which time every t r ace of unbound

water will be removed from the t i s s u e s .

I n f i l t e r a t i o n and Embedding; : The material i s now ready

for i n f i l t e r a t i o n . The t ransfer from the butyl alcohol

t o paraf f in w i l l be gradual. Paraff in wax will be changea

da i ly for at leas t three days to get the embedaing comp­

le t ed . Embeading cons is t s or pouring the content of the

container (with the i^arafrin i n melted condition) i n t o a

su i tab le r ecep t ac l e s , arranging the material i n proper

order and then quickly cooling the en t i re mass.

Mierotoming : The mater ia l will be ready for sect ioning

as soon as the Paraff in has thoroughly cooled. On the

rotary microtone the sec t ions form a ribbon as they are

cut one by one.

41

Mounting s The ribbon wi l i be cut i n t o sec t ions of con­

venient length. The sect ions will be pasted on the s l ides

by means of adhesive. As soon as the s l ides nave aried

thoroughly, they will be ready for s t a i n ing . Beiore

s t a in ing , the Paraffin wi l l be removed. Xylol wi l i be

used for t h i s purpose. From xy lo l , the s l i des wil l be

t ransferred to a j a r containing equal pa r t s of absolute

ethyl alcohol ana xylol . After 6 minutes i t wil l be

t ransfer red lo equal par ts of absolute alcohol and ether .

After 5 minutes, the s l i d e wil l be passed through 365)&

alcohol to water before placing i n the aqueous s t a in .

Staining and Dehydration :

The sect lors of s l id ing as well as rotary microtome

wil l be s ta ined with a number of s t a i n s alone and in com­

bination depending on the nature of study. The following

s ta ins will be used:

(1) Heldenhaln's Haematoxylin and Bismark brown

(Johansen, 1940),

(11) Heldenhaln's Haematoxylin and Safranin

(Johansen, 1940).

( i l l ) Safranin and Past green.

In a l l the above eases dehydration of the mater ia l

will be done i n ethyl-alcohol s e r i e s . The schedule for

s ta in ing with d i f ferent s t a ins i s gaia given below:

42

( i ) He ld^nha ln ' s Haematoxylin and Blsmark brown ( Johansen , 1940).

Sec t ions i n 50)fe a lcoho l

!l H

oO;fc Alcohol 5 0

Water 5 8 3

Iron alum 5 min. 0 5

3 wasnings with d i s t i l l e d water

5 5 4

Heidenhain ' s Haematoxylin 5 0

Removal of excess of s t a i n by i r o n alum. 1-2 min.

5 5

3 washings with water 0 0

30jg Alcohol 8 5 6

Eismark brown, 1-12 h r s . 5 0 0 5 il

Canada baisam and cover g l a s s

8 5

Xylene H i 5 il

Xylene l i 5 8

Xyl ene I 8 8

Carbol - xylene

Abs.

90 5

10%

50%

Washing ,

8 8 8

Alcohol 8 8

Alcohol 8 8 \

Alcohol 8 8

Alcohol 8 8

wioh 50% Alcohol

0 9 8 8

d , * , 6 . aee Appendix.

43

6 ( i i ) Heldenhain's Haematoxylin and Safranln

( Johansen, 1940 J :

i h i s s t a i n is naving the same schedule as the

previous one, except the difference t h a t tne Bisroark

brown i s replaced by bafranin for 1-li; hours after the

treatment with 50% ethyl alcotiol.

7 ( i i i ) Safranln ana i'ast green :

Tnis IS a common suain, in T-his proceaure ixrau

t he Sections wi l l be t r e a t e d with aqueous safranln for

1-12 hours and then they will be dehydrated. After ^b%

alcohol , sections wil l be t r e a t e d in Kast green i n clove

o i l medium for 2 minutes. The excess of Fast green wi l l

be removed in clove o i l . The sections w i l l be cleaned

in xylene and then mounting wil l be done i n Canaaa

balsam.

Maceration technique : This technique is applied, for

the study of pericarp and seed coat , following the pro­

cedure described by Ghouse and Yunus (1972) and Ghouse

et a l . , (1974).

A small port ion of the pericarp or the seed coat

wi l l be s l i ced (a f te r fixing In F. A. A, for about 5 days)

6-7. See Appendix.

44

i n tangentisG. plane. It w i l l then be t rea ted with 5%

Na OH solut ion for 3-5 days at 45-50°C, t o soften the

t i s s u e s . They will be t ransferred to fresh Na OH solu­

t i on of the same concentrat ion after 72 hours. Periodic

checking of the t rea ted material wi l l be done t o know

the actual condit ion. The treatment wi l l remain as such the

t i l l / c e l l s of the mater ia l become loose .

After get t ing the desired s t age , the material

w i l l be washed and stained i n Bismark brown or Safranin.

Peeling technique : In order t o get peelings of the seea

coa t , the f i r s t stage is to t r ea t the seed with d i l u t e

( 1 - 2 ^ HNO3-^ a few c rys ta l s of Pouassium c h l o r a t e , for

about eight hours. Heating i s t o be avoided.

After gett ing the des i red s t a g e , the material

will be washed and s ta ined with Heidenhain's Haematoxylin

and Bismark brown (Johansen, 1940).

Technique for the study of Endosperm:

For the study of endosperm, the method described

by Radley (1977), wi l l be followed:

Here, one ena of the seed is removed, allowing

i t t o be held on a card covered with Petroleum j e l l y ,

in th i s way cut surface t o be examined can be held facing

45

upwards. Colourless na i l varnish , d i luted with acetone

i f necessary, applied with a p ipe t t e to the cut surface.

After about an hour the piece of seed is immersed in

water for an hour or more. This enables the rep l i ca to

be removed without s t rach grains adhering to i t . The

rep l i ca i s f loated on d i s t i l l e d water on a s l i d e ana,on

drying, i t w i l l adhere to the s l i d e . To examine i t unuer

the microscope the top sur iace of the r e p l i c a i s flooded

with water without using a cover g lass .

Histochemical s tudies of the mature seed :

Seeds often contain la rge quant i t i es of tannins

and other pigments which may in t e r f e re with the micro­

scopic examination of s ec t i ons . In t he present i n v e s t i ­

gation the foHewing temporary s ta ins will be used for

c e l l contents (Vaughan, 1970).

( i ) Iodine for s tarch and aleurone grains*

( i i ) Sudan I I I for o i l drc^s; 8

( i i i ) Nigrosin aM p i c r i c acid for aleurone grains .

8 . See Appendix.

APPENDIX

1. h\A3.A±

It Is a mixture of g l ac i a l acetic acid, formalin

and ethyl alcohol (formalin-aeeto-alcohol) in the follow­

ing proport ion:

Glacial acetic acid 6 cc

Formalin 6 cc

Ethyl alcohol (50%) 90 cc

2. Ale o-glycerol

This mixture comprises of the following proportion

of glycerine and ethanol :

SOJg (ILycerine 50 cc

dO% Ethanol 50 cc

3 . Iron alum (Ferr ic aflmonlum sulphate)

2% solution of i ron alum is prepared i n water.

This solut ion i s used as mordant or a f ixer to the s t a i n .

Solution will be prepared by dissolving 2g of the dye in

IJOO cc of d i s t i l l e d water.

4. Haemato xylin

The s t a i n i t s e l f has l i t t l e or no a f f in i ty for

t i s sues unless i ron (always in the fe r r i c form) or allu-

minlum i s present in the l a t t e r . 0.5?^ solut ion of the

47

dye will be prepared by dissolving the s t a in in lOO cc

of d i s t i l l e d water.

6. Bismark brown

Bisffiark brown so lu t ion can be prepared by dissolv­

ing 1 g i n 100 cc of 70% alcohol. I t s ta ins the ce l l u lo se

wall as brown.

6. Safranin

Safranin solution can be prepared by dissolving

2.25 g in 225 cc of 95^ alcohol and d i lu ted with equal

amount of water when needed. It s t a ins c u t i n , cnromatin,

i l g n i n and i n some cases ch io rop ias t s .

7 . Fast green

0 .5 - 1.00^ solut ion of Fast green i n absolute

alcohol w i l l be prepared. This is useful for d i f fe rent ­

ia t ing safranin. It s ta ins a l l the t i s s u e s .

8. Nigrosin (or Induli-Q black)

This solut ion i s specif ic for s ta in ing P-

Pro te in . It gives the aleur^one grains dark blue appear­

ance.

LITERATURE CITED

• i t o i c i , G.B. (1824) : Observat ions microscopiques sur

d l v e r s e s especes des p l a n t e s . Ann. S c i . Nat.

Bot. 2 : 41-70 and 211-248.

* (1S30) i Note Sur l a mode d ' a c t i o n du

Po l l en s u r l e s t i g m a t e . Ext r a i t d ' une l e t t r e

d'Amici a Mirbe l . Ann. S c i . Nat. Bot. 2 1 :

329-332.

* (1847) : Sur l a f econdat ion des Orch id ' ees .

Am. S c i . Nat. Bot. 7/8 : 193-205.

A r d i t t i , J . ( l967) : Fac to r s a f f e c t i n g the germina t ion

or orchid s e e d s . Bot, Rev, 3 3 : 1-83.

Areka l , G.D. ( l 9 6 l ) i Embryology of KLugia no to ni ana.

Bot, Gaz. 123: 144-150.

Arnott , H,J, (1962) : T^e seed, g e r m i m t i o n , and s e e d l i n g

of Yucca. Ca l i f . Univ, , P u b i s , , Bot. 36:

1-164.

AyyangaT, G,S, (1948) : Some obse rva t ions on s comata

founa on c o t t o n ovules , Indian Cotton Grow.

Rev, 2 : 387-192,

B a i l e y , I . W, (1956) t Nodal anatomy and v a s c u l a t u r e

of s e e d l i n g s . J , Arnold Arboretum, Harvard

Univ. 37 : 269.

•Baude, E. (.±956) : Die Embryoentwicklung von S t r a t i o t e s

a lo ides L. P l a n t a 4 6 : 649-671.

49

•Berg, 0. (3898) : B e i t r a g zur kenntn ts d e r wnt-wicKLung

des Qnbryosackes d e r Angiospermen.

D i s s e r t a t i o n , Er langen.

Bhadur i , P . N . ( 1 9 3 6 ) : S tud ies on t h e onbryogeny of the

Solanaceae. I . Bot . Gaz. 98 s 283-295.

Bhandar i , N.N. ( i962) : S tud ie s in the family Ranuncu-

l a c e a e . I I I . Development of t h e female

gametophyte i n Adonis annua L. Phytomor-

phology 12: 70-74.

(1966) : S tud ies i n the fami ly Ranuncu-

l a c e a e , IX. Embryology of Adsnis. D i l l . &x

Linn. Phytomorphology 16: 578-687.

(1968) : S tud ies i n t h e family Ranuncu-

l a c e a e . X, Embryology of Anemone L. Phy­

tomorphology 18: 487-497.

and Vi jayaraghavan, M. R. (1970) :

S tud ies i n t h e family Ranunculaceae. XI I .

Embryology of Aqui leg ia v u l g a r i s . B e i t r .

B i o l . P f l anz . 4 6 : 337-354.

Bhatnagar , S .P . and J o h r i , B.M.(1972): Development of

Angiosperm s e e d s . Seed Bi iogy. Vol, I .

Academic P r e s s , New York and London.

and P u r i , S. (1970) ; Morphology and emb­

ryology of J u s t i c i a betonicg. Linn. Oes t e r r .

Bot . Z. 118: 6 5 - 7 1 .

60

Bocquet , G. (1959) : The campylotropous ovule . Phyto-

morphology 9 : 222-227.

Borthwick, H. A. (1931): Development of t h e macrogameto-

phyte and embryo of Daucus c a r o t a . Bot . Gaz.

92 : 23-44.

Boswel l , V. R. (1961) . V/hat seeds a r e and d o : An i n t r o ­

duc t ion . Year b , Agr. (U.S.D.A.) pp. 1.

Br ink , R, A. and Cooper, D.^. (1947) : Endosperm i n

seed devei opment, Bot . Rev, 1 3 : 423 apd 479.

B u e l l , K,M. (1962) i Developmental morphology i n

Uian thus . I. S t r u c t u r e of the p i s t i l and seed

development, Amer. J . Bofc, 3 9 : 194-210.

•Camerarius ,R . J . (1694) : "De sexu plantarum e p i s t o l a . "

Tubingen,

Camp, W.H. and Hubbard, M.M.( l963): Vascular supply

and s t r u c t u r e of t h e ovule and a r i l i n peony

and of the a r i l i n nutmeg. Amer. J . Bot. 50 :

174-178.

• C a r n i e l , K. (1967): Ueber d i e Embryobildung i n der

Gattung Paeonia. best e r r . Bot. Z. 114: 4 - 9 .

Cave, M.S. , Arno t t , H.J . and Cook, S. A, ( 1961 ) :

Embryogeny i n t h e C a l i f o r n i a Peonies with

r e fe rence t o t h e i r taxonomic p o s i t i o n . Amer.

J . Bot. 4 8 : 397-404.

61

Chikkannaiah, P .S . (1973)5 Development of endosperm,

embryo, and seed coa t i n Amlschophacell us

a x i l l a r i s L. P r o c . Ind ian Acad. Sc i . Sec t .

B 77(4) : 166-176.

C o m e r , E, J.H. (1949) j The annonaceous seed and i t s

four in teguments . New P h y t o l . 48: 332-364.

(1961) : The leguminous seed , Phytomor-

^ ^ J - ^ • C r e t e , P . (1956): L ' a p p l i c a t i o n de c e r t a l n e s donnees

^^ anbryologiques a l a sys temat ique des Oro-

banchac^es et de quel lques f a m i l i e s v o i s i n p s .

Ptiytomorphology 6: 422-436.

•Dahlgren Ji. v, 0. (1934) ; Die Kmbryologie von Impa,tien5

r o y l e i . Sv. Bot . T idskr . 28: 103-125.

Dathan, A.b.K, and bingh , D. (1970)$ Female garnet op hyte

and s e e a of (Jar lca candamarensis Hook. F ,

Plant b c i . (Lucknow) 2: 52-bO,

and (19V2)j Development of

embryo sac and seed in Bixa L. and Cochlosper-L

mum Kunth. J . Indian Bot . Soc, 6 1 : 254-266.

and (1973a) : S t r u c t u r e and

development of ovule and seed i n F l acou r t l a

Indica (Burn. F . ) M e r i l l , P roc . Indian Nat.

b c i . Acad. P a r t B. , B i o l , a c i . 39: 172-179.

52

and (1973b) : Development ana

s t r u c t u r e of seed i n I 'acsonla J u s s . and

P a s s l f l o r a L. Proc . Indian Acad. S c i . ,

S e c t . B 77!" 5-18.

Davis ,G,L.(1966) : "Systematic Embryology of t h e Anf^i-

osperms." New ^ork.

ueshpande, P.K. ( i y 7 6 ) : Development of embryo and endo­

sperm i n E r a g r o s t i s u n i o l o i d e s (Poaceae) .

naXit b y s t . Evol . 126: 253-259.

Dnyansagar,V. H, (1968): Embryological S tud ies i n t h e

Leguminosae. V I I I . Acacia aur icu lae for ia i s

A, cunn . , Menan the ra pavonina L i n n . , Ca l l -

l a n d r a hematocephala Benth. L loyd ia 21 :1 -25 .

Duke, J . A . ( 1 9 6 9 ) : On t r o p i c a l t r e e s e e d l i n g s . I . beeds ,

s e e d l i n g s , sys tems, and s y s t e m a t i c s . Ann.

Mo. Bob. Gard. 56 :125.

D u t t , M.(1953): Dividing n u c l e i i n coconut milk. Nature

(London) 171: 799.

Eames,A.J.( l9e)l) : "Morophology of t h e Angiosperms. "

McGraw-Hill, New York.

and Mac D a n i e l s , L.11.(1947): " I n t r o d u c t i o n t o

P lan t Anatomy," 2nd ed. Mc^Graw-Hi 1 1 , New lork

London,

E a r l e , F . R . and J ones , Q( l962) : Analyses of seed samples

from 113 p l a n t f a m i l i e s . Econ.Bot. 16: 221.

S3

Eckey, E.W. (1954)5 "Vegetable Fat and O i l s " , Re lnhold ,

New York,

Esau, K. (1960)5 "Anatomy of seed p l a n t s . " John Wiley and

sons , New York.

(1964)5 "Plant Anatomy." 2nd ed. W3.1ey Eas te rn

Pv t . , New D e l h i .

Fahn, A. (1969) : "Plant Anatomy." Pergamon Press , Oxford.

F l i n t , L.H. and Morel and, C . F . ( 1 9 4 3 ) : Notes on pho to-

s y n t h e t i c a c t i v i t y i n seeds of t h e s p i d e r l i l y .

Am^. J . Bot . 30 : 316-317.

Freeman, O.L.(1961)s In "Seeds. The year book of Agri­

c u l t u r e . " (A. S t e f f e r u d , ed. ) pp. v.U.S.D.A. ,

Washington, D.C,

•F rey -V^ss l ing , A . ( l 9 5 9 ) : Die p f l a n 2 a i c h e Zellwand. Spr inger -

Ver lag , B e r l i n .

Ghouse, A,K.M. and Yunus , M.(1972) : P r e p a r a t i o n of epideraial

peels from leaves of gymnosperms by t r ea tment with

hot 60$gHN03. S t a i n Technol . 47: 322-324.

, ,Fa rooqu i , F. and Sabir , D. (1974) :

A Simple macerat ion t echn ique for t h e s e p a r a t i o n of

Ms s i e v e elements from t h e barks of woody p l a n t s .

Curr . S c l . 4 3 : 424-425.

• Gut tenberg , H. von. (1960) : Grundzuge der His togenese

hoherer Pf lanzen. I . Die Angiospermen. In : Hand

buch de r Pf lanzenanatomie . Band 8 . T e i l 3 .

Gebmder B o r n t r a e g e r , B e r l i n .

64

•Haccius , B . ( i 9 5 2 a ) : Verbeitung und i iustui ldung d e r

E lnke imbla t t r i g i ce i t be i den Ufflbelllferen.

Oes te r r . Bot . Z. 99 J 483-506.

* ( ly52b) 5 Die fcteibryoentwicklung bei O t t e i i a

a l ismoides ytncL das i-'roblem deS te rmina ien

Monokotylen-Keimblat tes . P lant a 40:443-460.

* (1963) J H i s togene t i s che Untersuchungen an

WUrzelhaube und Kotyledonar sch ide g e o p h i l e r

Keimpflanzen (Podq)hylium und E r a n t h i s ) .

P l a n t a 4 1 : 439-458,

* (1954): Embryologische und U i s t o g e n e t i s c h e

s t u d i e n an "Monocotylen D iko ty l en" . I. C^a^::

t o n i a v i rg in lcgi L. Oes t e r r . Bo t . 'Z, 101 s

285-303.

•Harz, C D , (1885): "Landwer t schaf t l i che Samenkunde. "

P a r e y , B e r l i n . t

H a s k e l l , 0.(1^64) : P l e i o c o t y l y and d i f f e r e n t i a t i o n

wi th in angiosperms. Phytomorphology 4: 140-152.

•Hofmeis ter , W.(3S49). "Die Entstehung des Embryo d e r

Phanerogamen". L e i p z i g .

* (1861) : Neue B e i t r a g e zur Kenntnis d e r

Embryobildung d e r Phanerogamen. I I . Monocoty-

ledonen, Abh. Saechs, Akad, \ ^ s s . L e i p z i g , Mach.

Nafcurw. Kb, 7 : 629-760.

66

Jensen , W.A.(1962): "Botanical H i s tochemis t ry" . W.H.

Freeman & Go. , San Franc isco and London.

Johansen , D. A. (1940) : "Plant Micro technique" . McGraw-

H i l l , New York.

(1950) : ^Planfc embryology". Chronica Botan ica

Co. , ifeltham, Mass.

J o h r i , B.M, and Bhatnagar, S . P . ( I 9 6 0 ) : Embryology and

taxonomy of the b a n t a l a l e s . I . Proc. Nat. I n s t .

S c i . I n d i a , Part B 26 : 199-220.

and Garg,S. ( 1 9 5 9 ) : Development of endo­

sperm h a u s t o r i a i n some Leguminosae. Phytomor-

phology 9: 34-46.

and Singh, H . ( i 9 6 9 ) : The morphology,embryo­

l o g y , and sys temat ic p o s i t i o n of E l v t r a r i a

acau l i s (Linn) Lindau. Bot. No t i s . 112:227-251.

J o n e s , Q and E a r l e , F. R. ( I 9 b 6 ) : Chemical analyses of

s e e d s . I I . Oil and p r o t e i n c o n t e n t of 759

s p e c i e s . Econ. Bot . 20: 12*/.

J o s h i , P.C.4 wadhwani, A.M. (nee Ramchandani, S.) and

J o h r i , B.M.(1967): Morphological and embryolo-

g i c a l s t u d i e s or Gossyplum L. Proc . Nat. I n s t .

S c i . I n d i a , Par t B 33: 37 -93 .

Kadry, A,K. K. (1965) s The development of endosperm and

embryo i n Clstanche t i n c t o r i a (Fo r s sk . )G . Beck.

Bot . Not iser 108: ;::31-243.

66

*Kantor ,T,S. (1966) J Ob a c t i v n o s t i c h l o r o p l a s t o v zaroay-

sha I ' n a . (On t h e a c t i v i t y of c h l o r o p l a s t s of

f l ax embryo.) Mosttov. Glas/. Bot. Sad. Bui. 2 3 :

61-67 .

K ^ i l , R,N. (1968) : Morphological and embryologi cal .

s t u d i e s i n some Euphorpiaceae t o g e t h e r with a

d i s c u s s i o n on the sys t ema t i c p o s i t i o n of t h e

family. Ph.D. T h e s i s , Univers i ty or De lh i .

^nd Bhandari , N.N. (1964); Morphology and

embryology of Magnolia D i l l , ex Linn. P r o c .

Wat, I n s t . S c i . I nd i a , Par t B 30: ki45-262.

and Vani , R.S. ( i963) : Embryology and system­

a t i c p o s i t i o n of Cross osoma c a l i f ornicum Nutt .

Curr . S c i . 3 2 : 493-496.

_and V a s l l , I . K . ( a 9 6 3 ) : Ovule. In "Kecent

Advances i n the Embryology of Angiosperms"

(P . Maheshwari, ed. )pp . 41-67. I n t . Soc.

P l a n t Morphol. , D e l h i .

__and Walia, Ji. ( l 9 6 6 ) j The embryology of

Phylidrum I^nuginosum Banks, ex. Gaertn.

and the sys temat i c p o s i t i o n of the Jr'hyii-

d r a c e a e . B e i t r . B io . P f l a n z . 4 1 : 381-404.

Kausik, S . B . ( i 9 ^ 1 ) j Development of t h e vermiform appen­

dage i n G r e v l l l e a robust a Cunn. P r o c . Indian

Acad. S c i . , Sec t . B. 14: 13<'-140.

67

• K o l r e u t e r , J.C .(1761-1766) { "Vor lauf ige Nachricht von

e inlgen das Gesehlecht d e r Pflanzen b e t r e f f e n -

den Versuchen und Beobachtungen. "

Kozlowskl, T.T.and Gunn, C.R. ( l972)J "Importance and

c h a r a c t e r i s t i c s of s e e d s . " i n : Seed Biology.

Vol. I. Academic P r e s s , New York and London.

K u i j i t , J . ( i 9 6 9 ) : "The Biology of P a r a s i u i c Flowering

P l a n t s . " Univ. of C a i i l o r n i a P r e s s , Be rke ley .

*Lebegue,ft. (1962) J Rechjerches embryoginiaues sur quelques

D i c o t y l ^ o n e s D i a l y p ^ t a l e s . Ann. Des. Sc i . Nat.

Bo t . Ser . 1 1 , 13 ! l - lBO.

Linskens ,H.F. (1969) : F e r t i l i z a t i o n Mechanisins i n h igher

p lanus . In " F e r t i l i z a t i o n : Comparative Morpho­

l o g y , Biochemisur^ i^na inmunology" i,C.B. Metz

and A, Monroy, e d s . ) Vol. ki,pp. 189-253.

Academic P r e s s , New York.

Lubbock, J . ( i 8 9 ^ ) s " S e e d l i n g s . " Appleton, New York.

Maheshwari, P . ( 1 9 5 0 ) : "An I n t r o d u c t i o n t o t h e embryology

of Angiosperms. " McGraw-Hill, New York.

, Johr i ,B .M. and Dixii- ,S.N. (1957) : The

f l o r a l morphology and embryology of t n e Lora-

ni,noiaeae (Loran tdaceae ) . J . Madras U n i v . ,

bee t . B. ii7: 121-136.

58

Mares, D. J . ,Worstog, K. and b t o n e , B. A. ( 1 9 7 5 ) : Ear ly

s t ages in t h e development of wheat endosperm.

I . The change from f r e e nuc lea r t o c e l l u l a r

endosperm. A i s t . J . Bot . 2 3 : 311-326.

M a r t i n , A . C . ( i y 4 6 ) : The con?)arative i n t e r n a l morphology

of s e e d s . Aner. Mid i . N ^ u r . 36:613-660.

Mathur, N . ( l 9 6 6 ) ; The entoryology of Limanthes . Phyto-

morphology 6 : 4 1 - 5 1 .

M a t t h i e s s e n , A. ( l962) : A c o n t r i b u t i o n t o t h e embryology

of Paeonia . Acta. H o r t i . B e r g i a n i , 2 0 : 5 7 - 6 1 .

Maur i tzon , J . ( i 9 3 9 ) : Con t r ibu t ions t o t h e embryology of

t h e orders Rosales and Myr t a l e s . Acta. Univ.

Luna. 36 :1 -120 .

McClure,D.S.( 1957) : Seed c h a r a c t e r s of s e l e c t e d p l a n t

f a m i l i e s . lovra s t a t e c o l . J o u r . S c i , 3 1 :

649-682.

Meeuse,A,D, and O t t , ja, C.J . 11^62) : The occurrence of

c h l o r o p h y l l i n Nelumbo s e e d s . Acta Bot . i eeiyV ,

l and . 1 1 : 228.

Meier , H . ( i 9 5 8 ) : On the s t r u c t u r e of c e l l waUs ana c e l l

wall mannans iiom i v o r y nuts guia rrom d a t e s .

Biochem. e t Blophys. Acta 2 8 : 229-240.

Meyer,C.F. (1968) : Ce l l p a t t e r n s i n e a r l y embryogeny of

t h e Mcintosh app le , Amer. J . Bot. 46: 341-^4^.

5y

Mil l e r ,H . A. aM Wetmore,R.H. (1945) ; S tud ies i n t h e

developmental anatomy of Phlox drummondii Hook.

I , The embryo. Amer. J . Bot. 32 : 588-599.

Mis ra , R .C . (1964) : Development and s t r u c t u r e of angio-

sperm Seed. I I I . P lan tago L. Bul l . Nat. Bot.

Gard. , Lucknov. 1D5: 1-14.

(1970) : P l an tag lnaceae . In »'Syii?)osium on

Comparative On bryology ol" Angiosperms , " p p .

298-304. Indian Nat. S c i . Acad., New Delhi .

Mohan, K. (1970) : Morphological s t u d i e s i n So lanaceae :

V. Embryology as v;ell as s t r u c t u r e and develop­

ment of seed of S oj anum mac ran t hum Dung. Agra

Univ. J . Res. S c i . 19: 55-66 .

Mohan Ram, H.Y.(1960) : The development of t h e seed i n

Andrographis s e r p y l l i f o l i a . Amer. J . Bot . 47 :

215-819.

and Mas and, P . ( 1962 ) : Endosperm and seed

development i n Andrographis ech io ides Nees.

Curr . S e i . 3 1 : 7 - 8 .

Moskov, I . V . ( l 9 6 4 ) : The development of t h e embryo i n

some Paeonia v a r i e t i e s . Bot . Zh. 49: 887-S94.

Mukkada, A . J . ( 1 9 6 2 ) : Some obse rva t ions on t h e embryology

of Dlcraea s t j lM_a . In "Plant Embryology - A

symposium." pp. 139-145. Council S c i . I n d . R e s . ,

New Delh i .

60

(1963) : A c o n t r i b u t i o n t o t h e embryology of

I n d o t r i s t l c h a ramosisslma (wight) van. Roy en.

P r o c . Indian S c i . Cong. , 50th Par t I I I , Abstr .

387.

Murgai , P . (1959) : The development of t h e embryo i n

Paeon ia - A r e i n v e s t i g a t i o n . Phytomorphology

9 : 276-277.

(1962): Embryology of Paeonia t oge the r with

a d i s cus s ion on i t s sys temat ic p o s i t i o n . In

"Plant Embi-yoiogy - A synposium. " pp. 216-223.

Council Sc i . Ind. R e s . , New De lh i .

Hur ley , M. (1951) : Seeds of Cruc i f e r ae of n o r t h e a s t e r n

North America. Ame-r. Midi . Natur . 46 : 1.

Nast , C. G. (1941) : The embryogen/ and s eed l ing morpho­

logy of Juglans r e g i a L. L i l l o a 6 : 163: 205.

*Nawaschin,S.G. (1898) : R e s u l t a t e e ine r Revis ion d e r

Befruchtungsvorgange be i L i l ium martagon and

F r i t i l l a r i a t e n e l l a . Izv . Imp. Akad. Nauk. 9 :

377-382.

• N e t o l i t z k y , F . ( l 9 2 6 ) : Ana tomieder Angiospermen-Samen.

In "Handbuch d e r Pflanzen-Anatomie. "(K.Linsbauer,

ed. ) , Vol. 10, No. 14. B o r n t r a e g e r , B e r l i n .

Norstog, K. (1961): The growth and d i f f e r e n t i a t i o n of

c u l t u r e d b a r l e y embryos. Am^/. J . Bot. 48:

876-884.

61

Orr, M.Y. (1921) : The s t r u c t u r e of t h e ovular Integuments

aJxl development of the t e s t a i n Cleome and

I s o r a ^ i s . Notes Roy. Bot. Gard. , Edinburg 6 0 :

243.

P a l , A. ( 1974 ) ; S t r u c t u r e and development of seed i n

Croton o b l o n g i f o l l u s . Acta Bot. I nd l ca . 2 ( 2 ) :

147-150.

P a l i w a l , G.S. and Bhandar i , N.iV,(i962): S tomata l s t u d i e s

i n some Magnoliaceae. Phytomorphology 12:

409-412.

Periasano^, K. (2962) ; The rumina te endosperm. Develop­

ment arKi types of c-umination. In "Plant Embryo­

logy - A symposium." pp. 62-64 . Council S c i .

Ind. R e s . , New D e l h i .

and Swamy, B. G.L.( 1961) : S tud ies i n t h e

Annonaceae. I I . The development of ovule and

seed i n Cananga odoratgi and Mil l us a w i g h t i ^ a .

J . Indian Bot. Soc. 40: 206-216.

Pha t ak , V, G, and Ambegaokar, K .B. ( l961) : Embryological

s t u d i e s i n the Acanthaceae. IV, Development of

embryo sac and seed formation i n Haplanthus

t e n t a c u l a t u s Nees. J . Indian Bot. Soc. 40 :

625-634.

P i l l a L , S.K. , Ramasi ta , K. and D a t t , I . ( l 9 7 4 ) : Embryo-

geny, H i s togenes i s , a p i c a l merisLems, seed coat

and seed l ing anatomy of A l b i z z i a lebbek(Linn)

Benth. New Bot. 1 ; 23-33 .

62

*Poddubnaya-ArJno]^dl, V . A . ( l 9 5 2 ) : I s s l e d o v a n i e zarodyshei

u pokrjrtosemennykh r a s t e n i i v zhivom s o s t o i a n i i

(Study of anglosperm embryos i n l i v i n g s t a t e . )

Moskov. Glav. Bot. Sad. Bui . 14 : 3-12.

(1967): Comparative embryology

of Orchidaeeae. P. Maheshwari Mem. Vol . Phyto-

morphology 17: 312-320.

P r a s a d , K. (1977): Seed coa t s t r u c t u r e and development

i n Lepidlum sat ivum L. and Thlaspi p e n ' o l i a -

tum L« ( C r u c i i e r a e ) . Bot, uahrb . S y s t . Pf lan-

zengesch Pf lanzengeogr , , 97 : 508-514,

P u r l , V, (1941) : L i f e His to ry of Moringa o l e i f e r a Lamk.

J . Indian Bot, Soc. 20? 263-284.

Radley, M, (1977): A t echn ique for t h e examinat ion of

endosperm c e l l s i n c e r e a l c a r y o p s e s . Ann. Appl.

B i o l . 86: 133.

Raju, M.V.S. ( 1 9 5 6 ) : Embryology of the P a s s i f l o r a c e a e . I .

Gametogenesis and seed development of P a s s l -

H ora c a le ar a t a Mast. J , Indian Bot . Soc. 35 :

i a S - 1 3 8 .

RamchandanijS. , J o s h l , P , C . and Pundi r , N.S. (1966) :

Seed development i n Gossipium Linn. Indian

Cot ton J , 20: 97-106.

63

Rangan, T.S. aQd Rangaswamy, N.S. (1968) : Morphogenic

i n v e s t i g a t i o n s on p a r a s i t i c anglosperms. I .

C is tanche t u b a l o s a Wight (Family Oroban-

chaceae ) . Can. J . Bot . 4 6 : 263-266.

Rangaswamy, N.S. (1967): Morphogenesis of seed germina­

t i o n i n angiosperms. P. Maheshwari Mem. Vol .

Phytomorphology 17: 477-487.

Rao, V.S. ( 1 9 5 9 ) : "Nuclear endosperm" or " n o n - c e l l u l a r

endosperm"? Ann. Bot. 2 3 : 364.

Rau, M. A, (1963) : Some obse rva t ions on the endosperm i n

Pap i l i onaceae . Phytomorphology 3: 209-222.

Reeder, J . R . (1967): The embryo i n g rass s y s t e m a t i c s .

Amet. J . Bot . 44 : 756-768.

Reeve, R.M. (1946 a ) : S t r u c t u r a l composi t ion of t h e

s c l e r e i d s i n the integument of Pisum sativum

L. Amer. J . Bot . 3 3 : 191-204.

(]946 b ) : Ontogeny of the s c l e r e i d s i n t h e

integument of Pisum sat ivum L. Amer. J . Bot.

33: 806-816.

(1948): La te erabryogeny and h i s t ogenes i s i n

Pisum. Amer. J . Bot , 35: 591-602.

Rober tson, B .L . (1976) : Embryology of Jubaeops is C$iffra

Becca: EMospermand Embryogeny. J . S . Afr. Bot.

4 2 : 285-299.

64

Sachar , R.^. ( 1955) : The embryology of Argemone mexicang.

L. - A r e i n v e s t i g a t i o n , Phytomorphology 6:

200-218.

S a l i s b u r y , E . J . ( 1 9 4 2 ) : -Reporoductive Capaci ty of Plant^I

BelL , London.

•Sch le iden , M.J. (1837) : E in ige Bl icke auf d i e EntwLck -

l ungsgesch i ch t e des v e g e t a b l i s c h e n Organismus

bei den Phanerogamen. Arch. Bwl-Naturgeschichte .

I l l , 1: 289-320.

•Schlifflbaeh, H. ( 1 9 2 4 ) : B e i t r a g e zur Kenntnis d e r Samen-

anlagen uM Samen d e r Ameryll idaceen mit Beru-

ks i ch t igung des lifessergehaltes der Samen.Flora

(Jena) 117: 41 -54 .

•Schnarf , K. ( l929) : Bnbryologie der Angiospermen. In:

K. L insbauer . Handbuch d e r Pf lanzenanatomie .

Band 10, L ie f 24.

(1931) Vergle ichende Embryologie d e r

Angiospermen, Gebriider B o r n t r a e g e r , B e r l i n .

S c o t t , F.M., Bystrom, B. G. and Bowler, E. (1962) :

Cercidium fjoridum seed c o a t , l i g h t and e l e c t r o n

micrcBcopic s t u d y . Amer. J . Bot . 49: 821-833.

S e n t i , F. R. and Maclay, W.^ . ( l961) : Age-old uses of

seeds and some new o n e s . Year b . Agr. (U.S.D.A)

pp. 27 .

66

Singh , B. (1962) : S tud ies on the s t r u c t u r e and development

of seeds of Gucurb i taceae . I . Seeds of Echino-

c v s t i s wrjghtli Cogn. Phytomorphology 2: 201-

209.

( 1 9 6 3 ) : S tud ies on t h e s t r u c t u r e and development

of seeds of Gucurb i taceae . Phytomorphology 3 :

224-239.

(1964); Development and s t r u c t u r e of angiosperra

seed. I . Bu l l . Nat. Bot, Gard, , Luctcnow 89*

1-116.

S ingb, D.(1961): S tudies on endosperm and development

of seeds i n Gucurb i taceae and some of i t s r e l a t ­

ed f a m i l i e s . Agra Univ. J . R e s . , S c i . 10:117-124.

( 1 9 6 4 ) : Seed s t r u c t u r e i n the c l a s s i f i c a t i o n

of the Gucurb i taceae . P roc . I n t . Bot . Congr. ,

10 th , 1564 A b s t r a c t : pp. 616-517.

(1965) : Ovule and seed of Sechium edule Sw.-A

r e i n v e a t i g a t i o n . Gurr. S c i . 34: 696-697.

(1967): S t r u c t u r e and development of seeds of

the Gucurbi taceae . I . Seeds of B i sva rea Cogn,

Edgar ia Glarke , and Heroetos"^permum Hook, f.

P r o c . Indian Acad. S c i . , Sec t . B 66:267-274.

^ d JJathan, A.S.R. ( i5r,'2a). S t r u c t u r e and

development of seed coa t i n Gucurbi taceae : \ll.

Seeds oi Cucm-bita. Phytomorphology. 22:29-45.

66

aM Dathan, A.S.R.(1972b) : S t r u c t u r e and

development of seed coat i n Cucurbit ac eae :V I I I.

Seeds of Marah Ke l l . B u l l . Torrey Bot. C lub .99 :

239-242.

S inha , S.C, (1973): F r u i t ana seed morphology of Acacia

n l l o t i c a . Cr ibb . J . S c i . 18: 125-129.

•Soueges , R. (1938, 1939, 1948, 1951) J Embryogenle et

c l a s s i f i c a t i o n . Hermann, P a r i s .

* (1954): L ' o r i g i n e du cone v e g e t a t i f de l a

t i g e et l a q u e s t i o n de l a " t e r m i n a l i t e " du

co ty ledon des l^noco ty ledones , Ann. des S c i .

Nat. Bot . S e r . 1 1 , 15: 1-20.

* (1966): E s s a i d 'embryogenie conparee dans

l e s l i m i t e s des Hedysareed. Ann. des Sci l\(at.,

Bo t . Ser . 1 1 , 17 : 325-352.

• S t e f f e n , K . ( l962) : Die Embryoentwicklung von Imp at l ens

g l a n i u l i g e r a U d l . F l o r a . 139: 394-461.

• S t e i n e r , M. and oanke, 1. ( 195b) : Sind d i e Malpighischen

Zel len d i e Epidermis der Legumlnesei:ifcesta?

Oes te r r . Bo t . Z. 102: 542-550.

* t r a s b u r g e r , E . ( i « 8 4 ) : "Neue Untersuchungen uber den

Befruchtungsvorgang b e i den Phanerogamen."

Jena .

67

Subramanyam, K. (1961) s Plover s t r u c t u r e and seed develop­

ment i n Isot oma f l u v l ^ t l l l s F. v.M. r 'roc, Nat.

I n s t . S c i . , I n d i a , Part B 17: 275-286.

Swamy, B, G.L.C 1949) : Embryological s t u d i e s i n t h e Orchid-

aceae. I I I . Embryogeny. Amer. Midi. Natur . 4 1 :

202-232.

and Lakshmanan, K.K.(1962): The o r i g i n of o

epic l ty lary meristem and co ty ledon i n Hal op hi l a

oyata Gaudich. Ann. Bot . 26 : 243-249.

and Padmanabhan,i>, (1962): A reconna i s sance of angiosperm embryogenies. Ina ian Bot, S c i .

J o u r . 4 1 : 42id-439.

and Parameswaran, N. (1963): The Helob ia l

endosperm, B i o l . Rev. 3 8 : l_50 .

•Takhta jan , A.(1959): Die Evolu t ion d e r Angiospermen.

Gus tav-F isher , Jena .

Tan^a , S. ( 1 9 Y 0 ) : Embryology, s t r u c t u r e , and development

of seed and f r u i t of C a l c e o l a r i a mexicana

Benth. P l a n t . S c i . (Lucknow). 2s 61 -66 .

T i a g i , B. (1951) : S tudies i n the fami ly Orobanchaceae.

I I I . A c o n t r i b u t i o n to the embryology of Oro-

banche cernua and 0. a egyp t i aca . Phytomorpho-

logy 1: 168-169.

(1963): S t u d i e s i n t h e family Orobanchaceae.

IV. Embryology of Boschniackia h ima la ica and

68

B, t u b e r o s a , with remarks on the evo lu t i on of

t h e family . Bot . Not i s . 116: 81 -93 .

( I 96b ) : S tud ie s i n the family Orobanchaceae.

VI, Development of t h e seed i n Conopholis

americana (L. f i l . ) Water. Acta Bot , Szeged.

I I : k:63-261

•Treub, M. (1879) : Notes sur 1'embryogenie de quelques

Orchidees, Naturk, Verb, Kon, Akad,Amstepaam.

van de r P i j l , LlL95b)i S a r c o t e s t a , a r i l , pu lpa and the

evo lu t ion of t h e angiosperm f r u i t , 1 and I I .

P r o c , Kon. Med. Akad. Vifetensch. , t ier . C 58:

154-161 and 307-o l2 ,

(1957): On t h e ariLlloids of Nephelium.

Euphorbia . L i t c h i and Aesculus and t h e seeds

of Sapindaceae i n gene ra l . Acta Bot . Neer .6 :

6 1 8 - 6 4 1 .

Vaughan, J .G . ( l 9 7 0 ) : "The S t r u c t u r e and U t i l i z a t i o n of

Oi l S e e d s . " Chapman & H a l l L t d . London.

Venkateswarlu,J . and Lakshminarayana, L . ( 1 9 6 7 ) : A c o n t r i ­

b u t i o n t o the embryology of H y d r o c e r d c r i f l o r a

W.& A. Phytomorphology 7 : l94-20ii .

Vi jayaraghavan, M.R. (1962)} S tud ies i n t h e family

Ranunculaceae. I I . The female gametq)hyte of

Clematis eaur iana Hoxb. Phytomorphology 12:

45-49 .

69

.C1964): Morphology and embryology of a

vess e l l ess d i c o t y l e d o n - Sareandgra I r v l n g b a i l -

e y i , and sys temat ic p o s i t i o n of t h e Chloranth-

aceae . Phyt omorphology 14; 429-441 .

and Kaur, U . ( i 9 6 6 ) j Morphology and

onbryology of Turner a ulmi f o l i a L . and a f f i n i ­

t i e s of the family Turne raceae . Phyt omorpho­

logy 16: 639-563.

Wadhi, M, (1970); Acanthaceae: In "Symposium on Coapara-

t i v e Embryology of Anglosperms , " pp. 266-271.

Indian Nat. S e i . Acad. , New Delh i .

iferdlaw, C. W. (l!='65) ; Embryogenesis i n P l a n t s . John

vaiey & Sons , New York.

W5.thner, C.L. ( l959)» "The Orchids - A s c i e n t i f i c survey'.'

/ • •Yakovlev , M,S. (1961) : On t h e u n i t y of embryogenesis of •

the angiosperms and gyranosperras. P r o c , Bot .

I n s t . Acad. S c i . U.S.S.R. 7 : 366-365( in Russ ian) .

* (1968) ; P r i n c i p l e s of d e l i m i t a t i o n of

bas ic embryo types and t h e i r s i g n i f i c a n c e for

t h e phylogeny of angiosperms. In: Problemy

B o t a n i k i . I I I . Leningard . Izdat e l ' s t ovo

Akademmii Nauk, SSSK.

(1969) ; Embryogenesis and some problems

of p h y l o g e n e s i s . Rev. c y t o l . B i o l . veg . 32:

326-330.

70

and Yoffe, M. D. ( i y 6 7 ) : On some p e c u l i a r

f e a t u r e s i n t h e embryogeny of Paeonia* Phyto-

morphology 7: 74-82 .

and ( 1 9 6 1 ) : PUrther s t u d i e s

of t h e new type of embryogenesis i n t h e Angios-

perms. Bot . J . S c i . U.S.S.R. 46: 1402-1422.

• and . (196 6 ) : The embryology

of t h e genus Paeon ia L. In "Flower Morphology

and Reproauct lve P rocesses I n Angiceperms"

(M.S. Yakovlev, ed.) , pp. 140-176 Leningrad

( i n R u s s i a n ) .

Yarbrough, J . A. (1957); Arac his hypogaea. The s e e d l i n g

i t s e p i c o t y l and f o l i a r o rgans . Am«p. J . Bot.

44: 19-30.

• Or ig ina l not s een .