Screening Soybean Genotypes for Drought and Heat Tolerance |
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| Authors: | Val T Sapra Anthony O Anaele |
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| Institution: | Department of Plant and Soil Science, Alabama A&M University, Normal, U.S.A. |
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| Abstract: | Several soybean Glycine max (L.) Merr.] germplasms from maturity groups III through VII were evaluated at three osmotic potential levels (-0.017, 0.3 and -0.5 MPa) using polyethylene glycol M.W. 8000 and four temperature regimes (10, 25, 50 and 110°C) for drought and heat tolerance, respectively. Heat injury varied significantly among growth stages with the highest heat injury occurring at the flowering stage. Susceptibility to heat injury decreased toward maturity with the exception of a few genotypes. Genotypic variability was found among the lines in both drought and heat tolerance tests. This study identified the lines PI 408.155, PI 423.827B, PI 423.759 and Pershing as both drought and heat tolerant. In general, the larger-seeded lines failed to germinate at -0.50 MPa. A positive and significant relationship between promptness index and germina-tion stress index was found. However, no significant correlation was observed between germination stress index and the heat tolerance test. Based on the results from the germination test, lines PI 393.550, PI393.547, PI 86.103, PI 171.437, PI 86.490 and PI 423.852 had high germination stress indices and need further testing for heat stress tolerance. |
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| Keywords: | Glycine max L osmotic potential polyethylene glycol drought heat tolerance |
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