INFLUENCE OF PLANT HORMONES ON AGED SEEDS OF MAIZE·

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INFLUENCE OF PLANT HORMONES ON AGED SEEDS OF MAIZE·

Botany Department, University School of Sciences, Gujarat University,

Ahmedabad·380 009

Received on 16 June, 1989

SUMMARY

Seeds of maize (Zea mays L. cv. African Tall) were stored at 7.5% moisture content (m.c.) in 100 and 300 gauge sealed polythene bags at room-temperature (ambient: 35±5°C), in B.O.D. incubator (moderate: 25±1"C) and low temperature-(4-6°C). When seeds lost viability by 50% (after 12 months, at ambient and moderate temperatures), . seeds were presoaked for 6 h in the aqueous solutions of GAa. Kinetin (lo-'~ M) and dis­

tilled water. A remarkable increase in germination (50 to 70-90 %) was observed. Seedl­ ing growth in terms of length, fresh weight and dry weight was also enhanced. Untreated seeds lost viability after 16 months, whereas pretreated seeds took 20-22 months to lose its full viability.

INTRODUCTION

Preservation of vigour and viability of stored maize seeds, especially of carry

over stocks poses serious problem. The lower temperature and lower moisture con­

tent are effective in prolonging the longevity and maintaining the quality of the

agriculturally valuable seeds (Agrawal, 1980). Packing of seeds in moisture-vapour

proof containers and placing them at relatively lower temperatures maintained the

viability for comparatively longer periods (Bhattacharya et

01,

1983).

The treatment with PGRs (Plant growth regulators) need careful investigations

as different researches have given conflicting results (Heydecker, 1973). Thus present

study was conducted to obtain information on the response elicited by PGRs treat­

ment to seeds during storage.

MATERIALS AND METHODS

PLANT HOR.MONES ON MAIZE SEEDS

₁₀₉

seedling length, fresh weight and dry weight of the seedling and moisture content of

seeds. Stored seeds were germinated in petridishes lined with filter paper, moistened

with distilled water for 120 hours, in the B.O.D. incubator under continuous white

light and temperature (25± 1°C).

Seed treatment:

When seeds lost viability by 50 percent at 12.3 percent mois­

ture content they were soaked in double the volume of aqueous solutions (v/w) of

gibberellic acid (GAl), kinetin (KN)

M) and distilled water (DW) for 6 h,

dried back to their original weights and stored again under the same conditions.

Again the data (germination performance and moisture content) were recorded at

regular intervals from the different conditions and treatments. The untreated seeds

served as control.

RESULTS AND DISCUSSION

The seedling performance initially was low but became very pronounced

after storage for 4 to 6 mOilths. The same decreased with the advancement of storage

period. The germination per cent was 100 in the beginning with moisture content- of

7.5 percent (Fig.

In selected treatments, OW appeared to be equal to GAl (Figs. 1,2). Both the

treatments enhanced the per cent germination (30-50) and retained viability for 24-28

months under ambient (100 gauge stored seeds) and moderate (300 gauge po]ythene

bags) conditions (Figs. 1-4), whereas they lost viability in 300 ambient and 100

moderate treatments (Figs. 2 and 3). Kinetin too improved germination. percent

of 300 gauge stored seeds under moderate temperature (Fig 4). However it was

interesting to note that all the treatments significantly increased seedling length,

fresh weight and dry weight.

There was little difference in moisture percent between the control and

variously treated seeds during the course of ageing. In untreated seeds moisture was

more than 16 percent after 24 months (Fig. 1). Treatments were efficient in prevent­

ing moisture gain.

All the three treatments (OW, GAl, KN) were significantly superior over the

untreated seeds (P>O.OI) (Table

300 gauge moderate was found to be superior

over other storage conditions (100 and 300 ambient, 100 moderate) (Table

The values observed (in the increase) just after the treatment in germination

have shown significantly higher values compared to untreated seed (OW and GA

P>O.OI. KN P>0.10).

110

Fi9. 1 Fig. 2

aged seeds is now possible, (Saxena and Maheshwari, 1980; Saxena and Pakeeraiah,

1986). Tilden (1985) observed that slow hydration followed by dehydration with

PGRs produced better seedlings and higher germination' than untreated seeds.

According to Basu and Dhar (1979) the presoaking of seeds during storage gave

better seedling performance and establishment and also increased yield in several

crops. Further it has an advantage 'of enhancing the storage life of

seeds

(Savino

et al., 1979).

The pretreated seeds generally perform better and the advantages persist till

the last phase of the life cycle, however, this all depends on many factors such as

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PLANT HOllMONES ON MAIZE SEEDS

111

Table

1.

Influence of Pre-soaking treatments (Disti1led water, GAl. KN (10-

M) on

aged seeds stored in different containers (100 and 300 gauge polythene

bags) at ambient (35

±

5°C) and moderate (25

±

1 "C) temperatures on

germination percentage. Analysis of variance: (original values)

Conditions Treatments

Gauge Storage

and temp. months Unt DW GAs

KN

100 ambient 12 50 70 70 80 65.0

16 10 60 70 60 50.0

20 0 40 40 20 25.0,

24 0 10 10 0 5.0

300 ambient 12 50 80 80 70 70.0

16 30 60 60 50 50.0

20 0 40 20 10 17.5

24 0 0 0 0 0

100 moderate 12 50 80 80 80 12.5

16 30 50 50 50 45.0

20 0 30 10 20 15.0

24 0 0 0 0 0

300 moderate 12 50 100 100 90 85.0

16 20

tOO

20 0 80 70 70 52.5

24 0 40 40 30 27.5

Mean 17.5 52.5 48.8 43.8

Treatments Conditions

t L.S.D. L.S.D.

0.01 18.6 21.3

1).05 9.6 14.4

0.10 6.7 11.0

Table II. Analysis of variance: The increment in germination percentage over

control after the treatment

Conditions Container Treatments

(polythene

bags) Unto DW GAs

KN

Ambient 100 gauge 40 70 70 80 65

Ambient 300 gauge

SO

Moderate' 100 gauge 50 80 80 80 12.5

Moderate 300 gauge ,50 100 100 90 85

Mean 47.5 82.5 82.5 80.0

Treatments

t L.S.D.

0.01 20.2

0.05 10.5

112

hormone with proper concentration and the type of seeds (Saxena, 1979; Saxena

and Pakeeraiah, 1986).

Seeds stored in sealed po1ythene bags gave higher percent germination

(Bhattacharya et 01.,

1983). According to Kaur and Srivastava (1982) low tempera­

ture helps in lowering some biochemical parameters associated with the loss of seed

vigour.

In general all the presoaking treatments increased the viability of aged seeds,

and can

be

further explored.

ACKNOWLEDGEMENT

Thanks are due to Gujarat Government for the award of Research Scholar­

ship and to Head, Botany and Dr. O.P. Saxena for providing facilities and guidance.

REFERENCES

Agrawal, P.K. (1980). Relative storability of seeds of ten species under ambient conditions. Seed

Res., 8(2): 94-99.

Basu, R.N. and Dhar, N. (1979). Seed treatment for maintaining vigour, viability and producti­ vity of sugar beet. (Beta vulgaris) Seed Sci. and Technol., 7 (2) : 225-233.

Bhattacharya, P., Samul, R.C. and Sen, S. (1983). Studies on the germination and viability of stored sunliower seeds. Seed Res., 11 (2) : 162-171.

Heydecker, W. (1973). Panel discussion. Presowing treatments. In: Seed Ecology. (Ed.) W. Heydecker. "Butterworths, London. pp. 521-531.

Kaur, J., Srivastava, A.K. (1982). Effect of different storage conditions on some biochemical parameters associated with the loss of seed viability in soybean. Jour. Res., PAU: 19(4) : 368-373.

Roherts, E.H. (1972). Storage environment and the control of viability 2. In: Viability of seeds (Ed) E.H. Roberts. Chapman and Hall Ltd. London, pp. 14-58.

Savino, G.P.M., Haigh and P. De Leo. (1979). Effect of presoaking upon seed vigour and viability during storage. Seed Sci. and Technol., 7 (1) : 57-64.

Saxena, O.P. (1979). Physiological aspects of seed deterioration. In: Current Advances Plant Reproductive Biology (Ed.) C.P. Malik. Kalyani Publishers, New Delhi. pp. 328-348. Saxena, O.P. an::! Maheshwari, D.C. (1986). Influence of growth hormones and accelerated ageing

on growth and yield in soyabean, 19th ISTA, Vienna, June 6-12, Preprint No. S-I : 1-5. Saxena, O.P. and Pakeeraiah, T. (1985). Seed deterioration studies. Indian Rev. Life Sci., 6:

180-214.