Seed Germination under Simulated Water Stress as Drought Tolerance Test in Maize
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Authors
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J.S. BHAT
Division of Genetics, Indian Agricultural Research Institute, New Delhi 110 012
Author
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R.D. SINGH
Division of Genetics, Indian Agricultural Research Institute, New Delhi 110 012
Author
Keywords:
Drought tolerance, osmotic stress, germination, PEG, mannitolAbstract
Six inbreds possessing various degrees of drought tolerance along with their 15 F₁s were used to study seed germination and early seedling growth under simulated drought using polyethylene glycol (PEG) and mannitol solution at 0.5 MPa (-5.0 bars). Germination percentage decreased greatly under osmotic stress. The results obtained in PEG and mannitol were parallel. However, tolerant parents and hybrids showed less decrease in germination percentage. Reduction in root and shoot length and increase in root-shoot ratio were some other effects of osmotic stress on early seedling growth. Osmotic stress caused greater decrease in shoot length. However, tolerant genotypes showed lower decrease in root length and increased root-shoot ratio. Almost similar trend was noticed in F₁, F₂ and backcrosses. This suggested the utility of laboratory screening by taking per cent decrease in germination and increased root-shoot ratio as criteria for preliminary screening of genotypes for drought tolerance. The germination percentage in osmotic stress showed positive correlation with root-shoot ratio and grain yield under rainfed and limited irrigation conditions.
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References
1. PARMAR, M.T. & R.P. MOORE (1968). Carbowax-6000, mannitol and sodium chloride for simulating drought conditions in germination studies of corn (Zea mays L.) of strong and weak vigor. Agron. J., 60: 192-195.
2. MANOHAR, M.S. & W. HEYDECKER (1964). Water requirements for seed germination. Report, Univ. Wottingham School of Agriculture, 55-62.
3. THIMMAN, K.V. (1954). The physiology of growth in plant tissues. Amer. Sci., 42: 589-606.
4. CHAPMAN, S.C. & H.J. BARETTO (1996). Using simulation models and spatial database to improve the-efficiency of plant breeding programs. In: M. Cooper, and G.L. Hammer (eds.). Plant Adaptation and Crop Improvement. Wallingford, U.K. CABI, ICRISAT, and IRRI, pp. 563-590.
5. WEBER & B.R. MOORTHY (1952). Heritable and non-heritable relationship and variability of oil content and agronomic characteristics in F₂ generation of soybean crosses. Agron. J., 44: 202-209.
6. WILLIAMS, T.V., R.S. SNELL & C.E. CRESS (1969). Inheritance of drought tolerance in sweet corn. Crop Sci., 9: 19-23.
7. TRAPANI, N. & M. MOTTO (1984). Combining ability for drought tolerance tests in maize populations. Maydica, 29: 325-334.
8. MARTINIELLO, P. & C. LORENZONI (1985). Response of maize genotypes to drought tolerance tests. Maydica, 30: 361-370.
9. SUBBA RAO, M. (1992). Genetic studies on drought tolerance in maize (Zea mays L.). PhD. Thesis. IARI, New Delhi.
10. SINGH, K.P. & K. SINGH (1983). Influence of simulated water stress on free proline accumulation in Triticum aestivum L. Indian J. Plant Physiol., 26: 319-321.
11. BOUSLAMA, M. & JR. W.T. SCHAPAUGH (1984). Stress tolerance in soybean 1. Evaluation of three screening techniques for heat and drought tolerance. Crop Sci., 24: 933-937.
12. ASHRAF, C.M. & S. ABU-SHAKRA (1978). Wheat seed germination under low temperature and moisture stress. Agron. J., 70: 135-139.
13. WINTER, S.R., J.T. MUSICK & K.B. PORTER (1988). Evaluation of screening techniques for breeding drought resistant winter wheat. Crop Physiol., 28: 512-516.
