An evaluation of seed and seedling drought tolerance screening tests in wheat
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A series of experiments was performed in order to evaluate the significance of seed germination and seedling growth in osmotic media as screening methods for drought tolerance.
Ten spring wheat (Triticum aestivum L. em Thell.) and one durum wheat (Triticum durumDesf.) were tested under controlled environments, using polyethylene glycol-6000 (PEG) solutions as the moisture stress inducing media.
Tolerance in the rate of endosperm utilization, under stress, prior to the onset of germination varied among cultivars.
Germination rate or injury to germination at various concentrations of PEG differed significantly among cultivars. Cultivar rating with respect to injury to germination changed with stress levels. Injury to germination did not correlate with endosperm utilization rate in PEG or in water.
Germinating seedlings were tolerant to extreme desiccation up to the stage of emergence of the first leaf from the coleoptile.
Growth of photosynthesizing seedlings was monitored as they were carried through an increasing concentration gradient of PEG solutions, ranging from −5.9 to −11.3 bars of water potential. Cultivars significantly differed in seedling growth tolerance to increasing levels of water stress. Seedling growth tolerance across cultivars was not correlated with their germination responses under srress.
It is concluded that tolerance to water stress in growing seedlings can be screened for by using PEG-containing nutrient solutions. It can not be predicted from germination tests in osmotica.
Work was done under a US-Israel Binational Science Foundation (BSF) Grant no. 1654/78.
Index wordsWheat Triticum aestivum bread wheat Triticum durum durum wheat drought tolerance germination seedling growth water stress selection
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- Ashraf, C. M. & S. Abu-Shakra, 1978. Wheat seed germination under low temperature and moisture stress. Agron. J. 70: 135–139.Google Scholar
- Ashton, T., 1948. Technique of breeding for drought resistance in crops. Tech. Commun. Comm. Bur. P1. Breed. Genet. no. 14.Google Scholar
- Bassiri, A., M. Khosh-khui & I. Rouhani, 1977. The influences of simulated moisture stress conditions and osmotic substrates on germination and growth of cultivated and wild safflowers. J. agric. Sci. 88: 85–100.Google Scholar
- Brown, R. W. & B. P. van. Haveren, 1972. Psychrometry in water relations research. Utah Agric. Exp. Stn., 342 pp.Google Scholar
- Helmerick, R. H. & R. P. Pfeifer, 1954. Differential varietal responses of winter wheat germination and early growth to controlled limited moisture conditions. Agron. J. 46: 560–562.Google Scholar
- Johnson, D. A. & K. H. Asay, 1978. A technique for assessing seedling emergence under drought stress. Crop Sci. 18: 520–522.Google Scholar
- Kilen, T. C. & R. H. Andrew, 1969. Measurement of drought resistance in corn. Agron. J. 61: 669–672.Google Scholar
- Milthorpe, F. L., 1950. Changes in the drought resistance of wheat seedlings during germination. Ann. Bot. 14: 79–89.Google Scholar
- O'Toole, J. C., R. S. Aquino & K. Alluri, 1978. Seedling stage drought response in rice. Agron. J. 70: 1101–1103.Google Scholar
- Saint-Clair, P. M., 1976. Germination of Sorghum bicolor under polyethylene glycol induced stress. Can. J. Plant Sci. 56: 21–24.Google Scholar
- Slavik, B., 1974. Methods of studying plant water relations. Springer-Verlag, New York.Google Scholar
- Williams, T. V., R. S. Snell & J. F. Ellis, 1967. Methods of measuring drought tolerance in corn. Crop Sci. 7: 179–182.Google Scholar
- Wright, L. N. & G. L. Jordan, 1970. Artificial selection for seedling drought tolerance in Boer Lovegrass (Eragrostis curvula Nees) Crop Sci. 10: 99–102.Google Scholar
- Younis, M. A., F. C. Stickler & E. L. Sorensen, 1963. Reactions of seven alfalfa varieties under simulated moisture stresses in the seedling stage. Aggron. J. 55: 177–181.Google Scholar