تعيين شاخصهاي مناسب مقاومت به خشكي در ارقام سويا وارداتي

Determination of the Suitable Drought Resistance Indices in Commercial Soybeans Varieties

In order to determine suitable drought resistance indices in soybean, 15 introduced soybean cultivars were evaluated in a balanced group block design with four replications in stress as well as in non-stress environments. Six drought resistance indices of TOL, SSI, MP, GMP, STI and Harm were assessed on the basis of seed yield in stress and non-stress conditions. The highest damage due to water deficit stress was found to exerted on seed yield. Stress intensity for cultivars in MG III and lV was high (SI=0.62) while for cultivars in MG V was low (SI=0.28). Therefore subsequent analysis for cultivars in MG III and lV was done separate from that for MG V. Based on the results of correlation between drought resistance indices and seed yield in stress and non-water stress environments in cultivars of MG III and MG IV, drought indices of GMP and STI exhibited a high correlation with seed yield in either environment. These indices were recognized as the best for selecting cultivars with high yield potential in either of the stress or non-stress environments. Based on the by-plot graph, cultivars Stressland, Cisne297705 and Williams were considered as resistant cultivars and were grouped into A zone. In cultivars with MG V, drought indices MP, GMP, STI, Harm revealed a high correlation with seed yield in both environments and were recognized as the best indices. Based on the by-plot graph, cultivar Hatchinson was recognized as a resistant cultivar in MG V.