Morphological Assessment of Drought Stress Tolerant Soybean Genotypes in Bangladesh

Soybean (Glycine max (L.) Merr) is the most important commercial grain legume and oil seed crop which represents the most important plant source of vegetable oil and protein in the world. The water stress tolerance of the fifty soybean genotypes was evaluated in a glasshouse at the Bangladesh Institute of Nuclear Agriculture (BINA). The study was carried out to identify the drought tolerant soybean genotype(s) for improving yield under rainfed conditions in Bangladesh. Drought stress was induced by withholding water completely from 21 days after emergence. The water stress was continued until wilting symptom persisted on plant overnight. Water stress caused an overall reduction in some morphological and yield contributing characters such as plant hight, number of branches plant-1, internode length, pod plant-1, seeds pod-1, hundred (100) seeds weight and finally the seed yield of soybean. The studied genotypes were categorized into four groups based on their yield reduction under drought stress conditions. Five genotypes YESOY-4, PK-416, Shohag, SBM-09 and Binasoybean-6 were categorized as tolerant (<35% yield reduction), fourteen genotypes were categorized as moderately tolerant (35%-60% yield reduction), twenty five genotypes were categorized as moderately susceptible (61%-80% yield reduction) and rest six genotypes were categorized as susceptible (>80% yield reduction). These five genotypes YESOY-4, PK-416, Shohag, SBM-09 and Binasoybean-6 study further for developing drought tolerant soybean verities which may be helpful for quality oil seed production.