Seed dormancy in tropical fruit crops and measure to overcome it

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The light of unconditional love awakens the dormant seed potentials of the soul, helping them ripen, blossom and bear fruit, allowing us to bring forth the unique gifts

that are ours to offer in this life. John wehwood

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University of Horticultural Sciences, BagalkotKITTUR RANI CHANNAMMA COLLEGE OF HORTICULTURE, ARABHAVI

Seed dormancy in tropical fruits and measure to overcome it.

1ST

Ch. Allaylay DeviUHS14PGM426Dept. of FSC

Seminar outline

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Introduction

What is dormancy ??..

Mechanism of dormancy

Types of dormancy

Significance and its problems

Research reviews

Conclusion

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Introduction

The seed, containing the embryo as the new plant in miniature,

is structurally and physiologically equipped to sustain the

growing seedling until it establish as new plant.

Some trait is acquired during evolution for capacity to survive

under unfavorable condition.

It’s a genetically inherited trait whose intensity is modified by

environment during seed development

One such trait is DORMANCY, an intrinsic block to

germination, exists.

Dormancy

“… A mechanism that prevents germination of a seed at an

inappropriate time” (Vivrette, Seed Technologist Training Manual,

Chap. 9)

“… The absence of germination of an intact, viable seed under

germination favoring conditions within a specific time lapse”. (Hilhorst,1995)

“… Seed dormancy is a block to the completion of germination

of an intact viable seed under favourable conditions”. (Hilhorst,

1995; Bewley, 1997; Li & Foley, 1997).6

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What is seed ???

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Classes of Seed

Orthodox seed

Recalcitrant seed

Intermediate seed

Orthodox seeds

What is Orthodox seed

Seeds which can be dried down to a low Moisture

Content of around 5% to 10% and successfully stored at low or

sub-freezing temperatures for long periods.

Orthodox seeds are seeds which will survive drying and/or

freezing during ex-situ conservation.

Examples-

Guava, Sapota, Banana, Apple, Cherry, etc.

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Recalcitrant seed

What is recalcitrant seed

Seeds which cannot survive drying below a relatively high moisture

content (30–50%) and which cannot be successfully stored for long

periods.

Recalcitrant seeds are seeds that do not survive drying and freezing

during ex-situ conservation.

Examples-

Jamun, Jackfruit, Mango, Litchi, Mangosteen,

Durian, Avocado, Citrus, Rambutan, etc.

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Intermediate seeds

Which exhibit the drying tolerance characteristic of the

orthodox seeds but are sensitive to low temperature storage

like the recalcitrant seeds.

Examples-

Papaya, Macadamia nut

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Mechanism of seed dormancy

There are three mechanism for imposing dormancy

1. Seed covering which restrict the water uptake, embryo

expansion, gas permeability, leaching of inhibitors .

2. Chemical inhibitors include growth regulator, etc.

3. Morphological aspects such as small and underdeveloped

embryos.

Baskin and Baskin, 2004

Factors affecting seed dormancy

1. Internal chemical inhibitors which may need to degrade or need to be leached

out.

2. Hard impermeable seed coats disallowing imbibition of H20.

3. Hydrophobic hairs or tissue covering seed.

4. Immature embryos needing an "after-ripening" period for internal chemical

changes.

5. Light or darkness requirements involving light intensity levels or wavelengths,

particularly in the red and far red wavelengths which influence the chemistry of

phytochrome molecules.

6. Oxygen content reaching the embryo. Many aquatic and wetland plants germinate

under water where 02 levels are low and may not germinate when exposed to air.

13Baskin and Baskin, 2004

Types of dormancy

Primary dormancy


1. Exogenousi. Physicalii. Mechanicaliii. Chemical

2. Endogenousi. Morphological a. Rudimentary b. Linear c. Undifferentiatedii. Physiological a. Non- deep b. Intermediate c. Deep

3. Intermediate i. Morpho- physiological a. Epicotyl b. Double dormancyii. Exo- endodormancy

Secondary dormancy 1. Thermodormancy 2. Photodormancy 3. Skotodormancy

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Classification and explaination of dormancy

Primary dormancy 1. Exogenous dormancy

i. Physical dormancy

Seeds coats are impermeable in water due to macrosclereid

cells, mucilaginous outer cell layer or hardened endocarp.

Depth of the puncture to the seed coat increased, so did the

permeability of seed coat to water.

Eg: Olive, Peach, Plum, Apricot, Cherry etc. (hardened

endocarp), Walnut and Pecan nut (surrounding shell).

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ii. Mechanical dormancy

Seed coats are too hard to allow the embryo to expand during

germination.

In nature coats are softened by environmental agents such as

acids in guts, microorganism in warm, moist, forest fire,

environment, etc.

To overcome horticultural – scarify with sandpaper, hot

water, acid, moist environment, fire and immature embryo.

Eg. Stones of olive, Pits of stone fruits, Shells of walnut.

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iii. Chemical dormancy

Presence of chemical inhibitors in the outer covering of the

seeds and fruits.

In nature overcome by heavy rains, some soil inhibits the toxins

such as ammonia given off.

In horticultural leach with running water, change the water

daily, excising embyro, chilling for a few days, use of hormone

gibberellic acid .

Eg. Citrus, Grapes, Apple, etc.

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2. Endogenous dormancy

i. Morphological dormancy – Embryo is not fully developed at

the time of ripening. Need additional embryo growth after

the seed is separated from the plant. Eg. Datepalm

a. Rudimentary – about pro-embryo stage. May be inhibitors

present .

b. Linear – at torpedo stage. Takes up about ½ of the seed

cavity. May be inhibitors present.

c. Undifferentiated – rare at fruit crops.

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To overcome horticultural :

Alternate warm and cool temperature.

Hormone such as GA3.

Exposure to cool temperature.

Some tropical spp. required extended period at high

temperature for full development of embryo. Eg. Date palm.

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i. Non- deepShort term and

disappear with

storage last up to

1-6 months

To overcome – dry

storage, pre-

chilling, light

alternating ,

KNO3 and GA3.

ii. IntermediateThe embryo itself

is quiescent, not

dormant and

germinate if

excised.

To overcome –

stratification and

GA3 treatment

response.

iii. DeepControl are within the

embryo itself.

To overcome

stratification which

required temperature,

light, aeration,

moisture, time,

hormone interaction.

ii. Physiological dormancy

3. Combinition (Intermediate) dormancy

i. Epicotyl dormancy

Separate after ripening required for epicotyl, radicle and

hypocotyl.

Seeds initially germinate during warm period, produce root

and hypocotyl growth.

Require 1-3 months chilling to released epicotyl from

dormancy.

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ii. Double dormancy

Combination of two or more types of dormancy is known as

double dormancy. It can be morpho-physiological or exo-

endodormancy.

Require chilling period for embryo, followed by warm period

for root, then followed by cold period for shoot growth.

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Secondary dormancy

Imposition of new dormancy mechanism under unfavourable

condition.

The critical point is that this dormancy occurs AFTER the seeds has

been separated from the plant. It is of three types:

i. Thermodormancy: high temperature induced dormancy.

ii. Photodormancy: prolonged exposure of seeds to an excess light

iii. Skotodormancy: required light for germination when they are

imbibed in dark for extended period of time.

To overcome this dormancy it requires chilling, light

or GA, etc.

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Significance


Permitting germination only when environmental conditions

favour seedling.

Survival as in fruit plants of temperate region.

Helpful in creation of a “seed bank”.

Dormancy can also synchronize germination to a particular time

of the year.

Seed disposal can be facilitated by specialized dormancy

conditions. For example modification of seed covering through

digestive tract of a bird or other animals.

…but, in horticulture ----- mostly a problem

It is a problem for plant establishment

Deep dormancy is difficult to remove.

May still be a problem in less domesticated genotypes.

Also a problem for seed evaluation.

Seeds will not germinate at correct time.

Cost of storage is more.

Additional cost in breaking dormancy.


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Aim: To determine the water uptake pattern of fresh and dry seed with or without scarification and to relate this with the anatomical and morphological features of testa and other associated stuctures in selected banana ecotypes.

African Journal of Biotechnology Vol. 10 (65), pp. 14373- 14379, 24 0ctober, 2011 ISSN 1684- 5315 © Academic Journals

Seed anatomy, moisture content and scarification influence on imbibition in wild banana (Musa

acuminata colla) ecotypes Adam. B. puteh, Elliah M. Aris, Uma R. Sinniah, Md. M. Rahman, Rosli

B. Mohamad and Nur. A.P. AbdullahDepartment Of Crop Science, University Putra Malaysia, 43400UPM Serdang, Selangor, Malaysia.Department Of Agronomy, Bangladesh Agricultural University, Mymensingh- 2202, Bangladesh.

Accepted 11 August, 2011

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Table : 1 Seed moisture content (%) of freshly harvested and air dried seeds of three wild banana ecotypes

Seed type Ecotypes

Krau White Serdang Red Serdang Yellow

Freshly harvested 58 ± 3 38 ± 3 47 ± 5

Air dried 24 ± 3 15 ± 2 21 ± 3

± indicates standard error of the means; seed moisture content (%): g H2O/100 g dry seed mass

Puteh et al., 2011

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Table : 2 Fruit and seed morphological characteristic of three wild banana (Musa acuminata) ecotypes

Morphological character

EcotypesKrau White Serdang Red Serdang Yellow

Fruit length (cm) 9.28 ± 0.27 9.21 ± 0.26 7.68 ± 0.43

Fruit width (mm) 7.62 ± 0.21 7.08 ± 0.13 5.36 ± 0.11

No. of seed per fruit 55.20 ± 5.65 107.3 ± 3.90 28.6 ± 2.99

100 seed wt (g) 4.64 ± 0.02 3.68 ± 0.02 4.01 ± 0.05

Seed length (mm) 6.42 ± 0.17 2.16 ± 0.03 3.05 ± 0.19

Embryo length (mm) 1.10 ± 0.04 0.72 ± 0.16 0.92 ± 0.03

Testa thickness (mm) 0.24 ± 0.01 0.36 ± 0.02 0.18 ± 0.01

Hilum gap width (mm) 0.88 ± 0.05 0.70 ± 0.02 0.78 ± 0.05

± Indicates standard error of the means.

Puteh et al., 2011

Puteh et al., 2011

Figure : 1 SEM photomicrographs showing transverse sections of seed coat anatomy of Krau White (A), Serdang Red (B) and Serdang Yellow (C) ecotypes.

AL: indicates aleurone layer; EN: indicates endosperm; ET: indicates endotesta; MT: indicates mesotesta and TG: indicates tegmen.

A) Krau White B) Serdang Red C) Serdang Yellow

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Figure : 2 SEM photomicrographs showing transverse sections of seed compounds of wild banana ecotypes. Arrow indicates the water channel formation between TE and OP.

Scale bar = 100 micrometre for A,B,C and D and 200 micrometre for E and F.

EM; embryo

EN; endosperm

OP; operculum

TE; testa

Fresh seeds Dry seeds

Serdang Red

Serdang Yellow

Krau White

Puteh et al., 2011

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Source df Increase in seed mass Ecotype (E) 2 0.0035866***

Seed moisture content (SMC) 1 0.0094861***

Scarification (S) 1 0.0043513***

Imbibition interval (I) 9 0.0003606***

E × SMC 2 0.0004971***

E × S 2 0.0032021***

E × I 18 0.0000802***

SMC × S 1 0.0000032 ns

SMC × I 9 0.00005519***

S × I 9 0.0000109 ns

E × SMC × I 2 0.0000425***

E × S × I 18 0.0000316***

SMC × S × I 9 0.0000136 ns

E × SMC × S × I 36 0.0000144***

Error 240

*** significant at alpha 0.01 and non significant denoted as ns at alpha = 0.05

Table : 3 Mean squares from the analysis of variance of ecotypes, scarification, seed moisture content and imbibition intervals on increase in seed mass

Puteh et al., 2011

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Figure : 3 Increase of seed mass of cut and uncut fresh and air dried seeds of three wild banana ecotypes during imbibition period

Puteh et al., 2011

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Aim: To examined the suitable storage temperature and seed moisture content for maintaining the high germination and viability rate of papaya seed cv. Sekaki after three months storage.

Journal Of Sustainability Science and Management volume 8(1), June 2013: 87- 92 ISSN: 1823-8556© Penerbit UMT

Effect of storage temperature and seed moisture contents on papaya (Carica papaya L.) seed viability

and germination Zulhisyam A. K. , Chuah Tse Seng, Ahmad Anwar Ismail, N.N. Azwanida , Shazani, S. and Jamaludin, M. H.Faculty Of Agro Based Industry, University Malaysia Kelantan, Jeli Campus, Locked Bag No. 100, 17600, KelantanDepartment Of Agrotechnology, Faculty Of Agrotechnology And Food Science, University Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu

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C) Stored at 28 C⁰

B) Stored at 4 C⁰A) Stored at 0 C⁰

Figure : 4 Changes in the percentage of germination of papaya seeds with moisture contents at 6%, 8%, 10% stored at 0 C, 4 C and 28 ⁰ ⁰C⁰

6%

8%

10%

Zulhisyam et al., 2013

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Figure : 5 Changes in the percentage of dormancy of papaya seeds with moisture contents at 6%, 8%, 10% stored at 0 C, ⁰4 C and 28 C⁰ ⁰

A) Stored at 0 C⁰ B) Stored at 4 C⁰

C) Stored at 28 C⁰

6%

8%

10%


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* Means with the same letter within the same column are not different at the 5% of significant level after determined by Tukey test

Table : 4 Changes in the presence of germination, dormancy, death and mean time germination (mtg) of papaya seeds with moisture contents at 6%, 8% and 10% stored at 0 C, 4 C and 28 C after three months storage.⁰ ⁰ ⁰

Temperature ( C)⁰

Moisture contents

(%)

Germination (%)

Dormancy (%)

Seed death (%)

Mgt (Day)

0 6 54± 7a* 46± 7c 18± 7c 22.83± 0.47a

8 33± 7b 67± 7b 50± 8c 21.85± 0.59a

10 62± 11a 38± 11c 63± 4ab 21.96± 0.51a

4 6 36± 4b 64± 4b 41± 8cd 22.28± 0.74a

8 34± 1b 66± 1b 50± 7bc 21.69± 0.34a

10 5± 8c 95± 8a 57± 4abc 7.44± 12.89a

28 6 32± 9b 68± 9b 30± 6c 21.76± 0.77a

8 3± 5c 97± 5a 60± 3ab 6.98± 12.10a

10 0.00± 0.00d 100± 0a 69± 5a 0.00± 0.00b


EFFECT OF GROWTH REGULATORS ON SEED GERMINATION IN GUAVA

*M. Kalyani, S.G. Bharad, Polu, Parameshwar

Department of Horticulture , Dr. Panjabrao Desmukh Krishi Vidyapeeth AkolAa – 444104, Maharashtra, India

International Journal on Biological Sciences, Vol. 5 (Issue II), pp. 81-91, 2014 ISSN No. 0976- 4518

Aim: To find out the effect of pre sowing treatments like water soaking, GA3, thiourea, hot water and acid treatments on germination percentage in guava cv. Sardar

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Treatment Days required for germination

Germination (%)

T1 = GA3 500 ppm 19.68 80.30 (63.65)

T2 = GA3 1000 ppm 19.20 83.79 (66.26)

T3 = Thiourea 2000 ppm 21.83 68.45 (55.82)

T4 = thiourea 4000 ppm 21.48 70.50 (57.10)

T5 = HCl 3 min. 23.54 66.47 (54.61)

T6 = HCl 5 min. 24.40 65.03 (53.75)

T7 = conc. H2SO4 3 min. 24.90 67.74 (55.39)

T8 = conc. H2SO4 5 min. 25.83 58.57 (49.93)

T9 = Hot water 25.33 67.52 (55.25)

T10 = Tap water 19.31 75.97 (60.65)

‘F’ test Sig. Sig.

SE (m) ± 0.17 1.27

CD at 5 % 0.52 3.76

Table : 5 Effect of different seed treatments on days required for germination and germination percentage.

38Kalyani et al., 2014

39

Aim: To know the effect of Pre- soaking of sapota cv. Kalipatti seeds in growth regulators in seed germination.

Karnataka J. Agric. Sci., 14(4): (1030- 1036) 2001

Effect Of Growth Regulators On Seed Germination And Seedlings Growth Of Sapota

Y. Pampanna and G.S. Sulikeri

Division of HorticultureUniversity of Agricultural Sciences, Dharwad- 580 005

(Received: July, 2000)

Treatment Germination Percentage

Weeks after sowing 3 6 9 12

GA 200 ppm 16.00 (23.50) 31.00 (33.80) 50.00 (45.15) 56.00 (48.53)

GA 300 ppm 17.00 (24.19) 49.00 (44.57) 73.00 (58.70) 80.00 (63.49)

GA 400 ppm 22.00 (27.94) 43.00 (40.97) 60.00 (50.78) 68.00 (55.57)

Ethrel 200 ppm 7.00 (15.16) 19.00 (25.18) 33.00 (35.05) 50.00 (45.00)

Ethrel 300 ppm 5.00 (12.63) 18.00 (25.07) 29.00 (32.54) 46.00 (42.51)

Ethrel 400 ppm 8.00 (16.12) 18.00 (25.01) 33.00 (35.05) 46.00 (42.70)

GA 200 ppm + Ethrel 200 ppm 21.00 (27.25) 32.00 (34.43) 67.00 (49.11) 73.00 (59.36)

GA 300 ppm + Ethrel 300 ppm 19.00 (25.18) 35.00 (36.25) 58.00 (49.70) 72.00 (58.08)

GA 400 PPM + Ethrel 400 ppm 35.00 (36.25) 59.00 (50.20) 77.00 (62.05) 90.00 (72.04)

Control- water soaked 0.00 (0.57) 9.00 (17.99) 19.00 (25.81) 32.00 (33.20)

Control- unsoaked 0.00 (0.57) 4.00 (11.37) 13.00 (21.10) 26.00 (30.61)

S.E.M. ± (1.16) (0.94) (0.91) (1.23)

C.D. at 1% (4.47) (3.62) (3.53) (4.77)

Table : 6 Effect of growth regulators on seed germination of Sapota under Laboratory condition

1. The value in paranthesis indicates arc- sin transformed value and the values without paranthesis indicates the original value 2. Seed coat was cracked and then soaked in growth regulators/ water for 24 hrs as per the treatment.

40Pampanna and Sulikeri, 2001

Treatment Shoot length of seedling

(cm)

Root length of seedling

(cm)

No. of leaves per seedlings

Seedling vigour index

(SVI)

GA 200 ppm 9.35 5.12 5.50 809.68

GA 300 ppm 9.88 6.05 5.94 1274.15

GA 400 ppm 10.65 6.73 6.63 1182.54

Ethrel 200 ppm 8.80 4.33 4.19 657.90

Ethrel 300 ppm 8.58 4.39 4.56 629.45

Ethrel 400 ppm 8.70 4.73 4.38 617.67

GA 200 ppm + Ethrel 200 ppm 9.33 4.69 5.31 1036.84

GA 300 ppm + Ethrel 300 ppm 9.65 5.14 6.31 1064.41

GA 400 PPM + Ethrel 400 ppm 10.28 5.48 6.75 1416.30

Control- water soaked 6.35 3.79 3.06 304.08

Control- unsoaked 4.90 3.13 2.69 208.76

S.E.M. ± 0.16 0.17 0.19 30.37

C.D. at 1% 0.63 0.66 0.73 121.21

Table : 7 Effect of pre- soaking of sapota seeds in growth regulators on growth of seedlings under laboratory conditions

41Pampanna and Sulikeri, 2001

Germination Capacity of Annonaceae Seeds (Annona muricata L., A. squamosa L. and A. senegalensis Pers.)

Cultivated Under Axenic Conditions

Oumar BA, Maurice SAGNA, Mame Oureye SY

Aim: To evaluate the in vitro germination capacity of Annonaceae seeds and to defined the optimal conditions favourable to their germination process

42

International Journal of Science and Advanced Technology (ISSN 2221- 8386) Volume 2 No. 6 June 2012

43

Scale Description Viability

1 Uniform red colour of the embryo and radicle

Very high probability of germination

2 Pale pink colour of the embryo and radicle

High probability of germination

3 Half of the cotyledon unstained Low probability of germination

4 Radicle unstained or damaged No germination

5 No colour No germination

Table : 8 Colour scale of the different parts of the seed (Moore, 1985)

Oumar et al., 2012

44

group 1 group 2 group 3 group 4 group 50%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Via

bilit

y (%

)

Group of Moore’s scale

Figure : 6 Distribution of Annona squamosa L. seed lots tested with TTC (1%) according to the protocol Moore (1985)

Oumar et al., 2012

45


10%

20%

30%

40%

50%

60%

70%

80%

90%

100%


Via

bilit

y (%

) Figure : 7 Distribution of Annona muricata L. seed lots tested with TTC (1%)

according to the protocol Moore (1985)

Oumar et al., 2012

46


10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Via

bilit

y (%

)


Figure : 8 Distribution of Annona senegalensis L. seed lots tested with TTC (1%) according to the protocol Moore (1985)

Oumar et al., 2012

47

Species Annona squamosa

L.Annona muricata L. Annona

senegalensis L. Treatments Infection

(%) Germination

(%) Infection

(%)Germination

(%) Infection

(%)Germination

(%)

Control seeds 100c 25a 100c 13a 100c 6a

Whole seeds 19b 29a 21b 21b 22b 16b

Shelled seeds 6a 73b 3a 60c 2a 60c

Table : 9 Infection and germination rates of disinfected or not and shelled or not (control groups) of Annonaceae seeds after 30 days of culture on sterile sand at 30 C

In column, for the same species and for the same parameter, values followed by the same letter are not significant different according to the Newman Keuls test (P≤ 0.05)

Oumar et al., 2012

48

Species Treatments Mean value of b CV (%)

A. muricata T1 3.25a 51.53A. muricata T2 5.20a 52.36A. muricata T3 15.34b 50.44A. squamosa T1 4.97a 67.44A. squamosa T2 7.47b 49.02A. squamosa T3 33.12c 18.45

A. senegalensis T1 2.08a 30.28

A. senegalensis T2 5.05b 36.47A. senegalensis T3 18.07a 38.15

Table : 10 “b” Parameter expressing the germination speed following different disinfection and mechanical scarification

treatments of Annona seeds.

T1: None disinfected and unshelled seeds;T2: Unshelled and disinfected seeds;

T3: Shelled and disinfected seeds;

CV: Coefficient of variation

Oumar et al., 2012

49

Combinations of treatments Mean value of b

ASE T1 2.082a

AM T1 3.245ab

AS T1 4.96bc

ASE T2 5.052bc

AM T2 5.196bc

AS T2 7.465c

ASE T3 15.342d

AM T3 18.066e

AS T3 33.124f

Table : 11 Comparison of “b” value between disinfection and mechanical scarification treatments applied to Annona species

ASE: Annona senegalensis;

AM: Annona muricata;

AS: Annona squamosa;

T1: None disinfected and unshelled seeds;

T2: Unshelled and disinfected seeds;

T3: Shelled and disinfected seeds;

Oumar et al., 2012

50

Table : 12 Infection and germination rates of scarified seeds or not with sulfuric acid (95%) after 30 days of culture on sterile sand at 30 C⁰

Species Annona squamosa L. Annona muricata L. Annona senegalensis Pers.

Treatments (min)

Infection (%)

Germination (%)

Infection (%) Germination (%)

Infection (%)

Germination (%)

T0 100h 9a 100g 2a 100h 1a

T5 94h 11a 93g 4a 90g 5a

T10 95h 11a 95g 9b 92g 7a

T15 87g 13a 93g 13b 82f 16b

T20 78f 15a 76f 15b 80f 15b

T25 78f 23b 60e 23c 74f 12b

T30 69e 25b 52d 22c 57e 16b

T35 52d 26b 33c 39d 52e 30c

T40 38c 48c 29c 35d 37d 33c

T45 18b 52c 16b 45e 19c 35c

T50 14b 69d 6a 59f 9b 59d

T55 3a 67d 1a 65f 1a 57d

T60 2a 70d 0a 65f 2a 58d

Oumar et al., 2012

51

Table : 13 Parameters expressing the germination speed following different pre- treatment time with concentrated sulfuric acid (95%) of

Annona seeds.Treatments

(min) Mean value of “b” Cv (%)

A. muricata A. squamosa A. senegalensis A. muricata A. squamosa A. senegalensis

T0 1.30a 2.64a 0.61a 29.28 38.06 33.26

T5 1.75a 2.94a 1.90a 37.10 43.70 28.19

T10 2.64ab 2.97a 2.24a 29.79 43.34 31.92

T15 4.42bc 4.42a 4.25b 32.95 29.79 41.37

T20 4.75c 4.75a 4.75b 26.80 32.95 32.95

T25 7.59d 8.14b 4.97b 28.19 26.80 35.54

T30 8.14d 8.59b 5.24b 40.25 27.74 16.89

T35 10.63e 8.84b 9.34c 31.06 30.26 35.43

T40 11.10e 13.59c 10.42c 39.24 38.48 27.88

T45 13.03f 14.38c 10.90c 25.85 42.42 32.68

T50 19.05g 18.52d 19.16d 28.28 43.70 28.58

T55 20.59g 21.03e 19.17d 33.82 34.10 30.18

T60 23.75h 24.13f 22.01e 24.23 25.45 23.04

Oumar et al., 2012

17 23 27 30 38 420%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

52

Temperature C ⁰

Ger

min

atio

n (%

)

Annona muricata

Annona senegalensis

Annona squamosa

Figure : 9 Effect of different thermal levels on germination rates of Annonaceous seeds

Oumar et al., 2012

Annona squamosa

Annona muricata

Annona senegalensis

0%10%20%30%40%50%60%70%80%90%

100%

53

Darkness

Light

Alternating Light and Dark

Ger

min

atio

n (%

)

Species

Figure : 10 Germination rates of Annonaceous seeds according to light conditions after 30 days of culture at 30 C⁰

Oumar et al., 2012

54

Objective: To know the effects of temperature regime and acid scarification on seed germination of Spondias mombin

Studies On The Dormancy and Germination of Stony Fruits of Hog Plum (Spondias Mombin) In Response

to Different Pre- soaking Seed Treatments

Fadima O.Y., Idown O.T.H. and Ipinlaye S.J.

Department Of Biological Sciences, Federal University Dutsin- Ma Katsina State, NIGERIAInstitute of Food Security, Environmental Resources And Agricultural Research, Federal University Of Agriculture, Abeokuta, P.M.B.

2240, Abeokuta, Ogun State, NIGERIAReceived 24th December 2013, Revised 16th February 2014, Accepted 15th March 2014

International research journal of biological sciences vol. 3(6), 57-62, June (2014) ISSN 2278- 3202

55

Figure : 11 Ripe fruits of Spondias mombin plant before extraction of seed

Fadima et al., 2014

56

Period of soaking Hot water treatment

80 C⁰ 90 C⁰ 100 C⁰ Control

1 mins. 35a 20a 15c 0d

2 mins. 15a 10b 10b 0c

3 mins 5a 5a 1b 0c

Table : 14 Effect of hot water treatments on seed germination of S. mombin at 22 days after sowing

Mean in the same row followed by the different letters are significantly different according to DMRT at P < 0.05

Fadima et al., 2014

Figure : 12 Percentage germination of S. mombin seeds subjected to hot water treatments

57Fadima et al., 2014

Period of soaking Oven drying heat treatment

80 C⁰ 90 C⁰ 100 C⁰ Control

1 mins. 25a 20b 15c 0d

2 mins. 20a 8b 2c 0c

3 mins 5a 1b 1b 0c


Table : 15 Effect of oven drying heat treatments on seed germination of S. mombin at 22 days after sowing


Figure : 13 Percentage germination of S. mombin seeds subjected oven drying heat treatments


Period of soaking Pre- soaking treatment methods

60% H2SO4 60% HNO3 60% HCl Control

15 mins. 50a 30b 20c 0d

20 mins. 55a 35b 30c 0c

25 mins 60a 40b 30c 0c

Table : 16 Effect of acid pre-soaking treatments on seed germination of S. mombin at 22 days after sowing



Figure : 14 Percentage germination of S. mombin seeds subjected to acid pre-soaking treatments

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15 20 25

Fadima et al., 2014

Aim: To evaluate different treatments for improving purple passion fruit seeds germination and determine the mycorrhizal dependency of this species on the AMF (Glomus fasciculatum)

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Germination and growth of purple passion fruit seedlings under pre- germination treatments and

mycorrhizal inoculation

Joaquin Guillermo Ramiraz Gil, Melissa Munoz Agudelo, Laura Osorno Bedoya, Nelson Walter Osorio, Juan Gonzalo Morales Osorio

ISSN 1983-4063- www.agro.ufg.br/pat – Pesq. Agropec. Trop., Goiania, V. 45, N.3, P. 257-265, Jul/Sep. 2015

Table : 17 Effect of pre-germination treatments on purple passion fruit seeds (Medellin, Colombia, 2012/2013)

Treatment Germination (%)

AGT (days) AGS (days) Viability (%)

T0 72.0a 28.3a 1.2a 85.3a

T1 50.0b 14.2b 1.3a 55.8c

T2 71.0a 25.2a 1.3a 81.2a

T3 69.2a 27.9a 1.5a 86.9a

T4 68.2a 24.5a 1.5a 78.9ab

T5 66.2a 21.3ab 1.4a 84.3a

T6 67.9a 15.2b 1.6a 86.1a

T7 68.3a 16.3b 1.8b 75.3b

T8 67.9a 10.3c 2.8c 79.1ab

AGT: average germination time; AGS: average germination speed. Averages followed by different letters indicate that they are significantly different, according to the Turkey test (P≤ 0.01)T0: control; T1: 2mm cut of the apical and basal seed ends; T2: cold/ warm stratification (12 hrs at 4 C ⁰and 12 hrs at 28 C; ⁰ T3: light (12 hrs of darkness and 12 hrs of light, using blue LED lights and red LED lights; T4: GA3 (400 mg/l); T5: H2SO4 (96% v/v) for I min.; T6: H2SO4 (96% v/v) for 5 min.; T7: H2SO4 (96% v/v) for 10 min.; T8: H2SO4 (96% v/v) for 20 min.

63Joaquin et al., 2015

64

Figure : 15 Visual appearance of the pre- germination treatments in the purple passion fruit seeds at 25 days after treatment application (Medellin, Colombia, 2012/2013).

Jaoquin et al., 2015

Figure:16 Effect of inoculum with G. fasciculatum, under three levels of P in the soil solution, on the biometric variables of purple passion fruit seedlings (Medellin, Colombia, 2012/2013).

Error bars represent the standard deviation indicate significant differences, according to the Turkey test (p ≤ 0.01)

65

Stem diameter (mm) Height (cm)

Biomass (g) Leaf area (cm2)

Joaquin et al., 2015

66

Figure : 17 Effect of seedling inoculation with G. fasciculatum, together with three levels of P in the soil solution, on the variables mycorrhizal colonisation, mycorrhizzal dependency and foliar P content (Medellin, Colombia, 2012/2013). Error bars represent standard deviation. Different letters indicate significantly different averages, according to the Turkey test (p≤ 0.01)


Figure : 18 Purple passion fruit seedlings at 90 days after inoculation with G. fasciculatum and three P levels in the soil solution (Medellin, Colombia, 2012/2013)

67


68

AIM : To determine the effect of seed moisture contents and germination ability on cryoconservation of tropical fruits from the Passiflora, Psidium and Caricaspecies

SEED CRYOCONSERVATION OF PASSION FRUIT, PAPAYA AND

GUAVA GERMPLASM*I. O. Obisesan1,3,4; Veiga, R. F. A.2,3; Barbosa, W.2,3; Meletti, L. M. M. 2; Lago, A. A.²;

Medina, P. F.2 and Razera, L. F.2¹ Department of Crop Production and Protection, Obafemi Awolowo University, Ile-Ife, Nigeria

² Instituto Agronômico (IAC), CP 28, 13001-970 Campinas, SP, Brazil3 Research Grant, CNPq (National Council for Scientific and Technological Development)

4 TWAS/UNESCO Visiting Associate

69

Table:18 Seeds moisture contents of seven fruit groups in different environments before cryopreservation and % germination (bold) at 31 DSP of cryopreserved seeds

Code for Groups:P1=Passiflora edulis group yellow; P2=Passiflora edulis group purpleP3=Passiflora nítida group wild; P4=Psidium guaiava group whiteP5=Psidium guaiava group red; C1=Carica papaya group mamaozinho andC2=Carica papaya group formosa

Obisesan et al., 2015

70

Table : 19 Mean % germination of seeds of seven groups of tropical fruit trees


71

% G

erm

inat

ion

% G

erm

inat

ion

% G

erm

inat

ion

Group of fruits

Group of fruitsGroup of fruits

Figure : 19 Germination of cryoseeds (Incubator) Figure : 20 Germination of cryoseeds (Desiccator)

Figure : 21 Germination of cryoseeds (Ambient temperature)


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Table : 20 Characteristic of ungerminated seeds of different groups at 31 DSP


73Group of fruits

Group of fruitsGroup of fruits

% D

orm

ant s

eeds

% fu

ngus

infe

cted

seed

s

% D

ead

seed

s

Figure : 24 % Dormant seeds in fruit groups

Figure : 22 % Dead seeds in fruit groups Figure : 23 % fungus infected seeds


Conclusion

It is an important survival mechanism that favors propagation and

dissemination of seeds to establish plant populations.

It may favor germination and seedling emergence under more favourable

conditions.

Some level of dormancy is desirable to prevent sprouting before harvest to

maintain seed quality.

Seeds from the same genotype may also have different dormancy levels or

intensities depending on the environment under which the seed developed.

Seed dormancy should be removed to get good germination and several

methods are available to remove the dormancy.

74

75

Thank

You… Thank

You…

Declining chilling and its impact on temperate perennial crops

C.J. Atkinsona, R.M. Brennanb, H.G. Jonesc

Natural Resources Institute, University of Greenwich and East Malling Research, New Road, Kent ME19 6BJ, UK b James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK c University of Dundee at James Hutton

Institute, Invergowrie, Dundee DD2 5DA, UK

Received 8 November 2012; Received in revised form 29 January 2013; Accepted 1 February 2013

Environmental and Experimental Botany 91 (2013) 48– 62

Aim: To outline why winter chill is important biologically and how it impacts on the

production of perennial fruit crops

Commodity

Vegetative bud break

Floral bud break

Bud abscission

Flower abscission

Flower quality

Reproductive morphology

Fruit set

Vegetative growth

Crop yield

Product quality

Apple * * * * * * *

Pear * * *

Cherry * * * *

Plum *

Peach * * * * *

Nectarine

* *

Apricots

* *

strawberry

* * * * *

Table : A summary of the different aspects of perennial fruit crop growth, development and production impacted by low winter chill.

Education

Seed dormancy in tropical fruit crops and measure to overcome it