Characterization of Morpho-Physiological Responses of Soybean Genotypes to Water Stress

A study was conducted from February to May 2024 at the Bangladesh Institute of Nuclear Agriculture (BINA) pot yard in Mymensingh, Bangladesh, using a completely randomized design with four replications. The study aimed to assess the effects of different levels of water stress on seed yield and key physiological traits across five soybean genotypes. Five soybean genotypes (Binasoybean-7, SBM-15, SBM-22, SCM-5, and SCM-11) and three levels of water deficiency (control: no water deficiency, water deficiency 40%, and 60% field capacity) were imposed at the pre-flowering stage and continued until physiological maturity. Plant height, branch density, total dry mass, leaf nitrate reductase activity, pod and flower output, seed yield per pod, harvest index, and seed yield per plant were all significantly reduced across all five genotypes as the stress level increased due to dryness. The chlorophyll and total sugar levels in leaves across all five genotypes increased with the increasing rate of drought. Drought stress significantly decreased the rate of photosynthesis in leaves. Among the five studied genotypes, only the Binasoybean-7 variety shown superior performance under drought stress circumstances for morphological, physiological, and yield-contributing parameters. Therefore among the five genotypes Binasoybean-7 could be used as genetic material for developing more drought-tolerant soybean varieties.