Abstract

                                Crop plants are often exposed to drought and high temperature stresses that decrease crop yield worldwide and the problem is expected to further accentuate in future. Drought is one of the most important environmental stresses affect the growth and development thereby reducing the yield to greater extent in many crops. Among the oilseeds, soybean plays key role as it contains high protein content and it is highly sensitive to drought stress. Developing soybean (Glycine max) cultivars that can perform well in drought and other abiotic stress is considered as important to attain global stability. Germination is one of the vital growth stages for seedling establishment and success in this stage is highly dependent on moisture availability in the soil. A laboratory experiment was conducted to assess the germination associated traits of forty seven genotypes of soybean under Polyethylene Glycol (PEG) induced drought. The optimum osmotic stress levels were maintained from 0 to -5 bars by altering the concentration of PEG. This investigation was performed in factorial experiment using Completely Randomized Design (CRD) with three replications. Germination and early growth were affected by drought stress. Decreasing water potential or increasing moisture stress adversely affected germination and all seedling growth related characters with every attribute reducing significantly with level of decreasing water potentials. The extent of reduction varied with the genotypes and water potential. The variation among genotypes for germination percentage, vigour index, stress tolerance index (STI), was found to be significant and reliable indicators to screen the drought tolerant genotypes at germination and seedling stage in soybean.

Key words : Drought, Germination percentage, Tolerance index, Vigour index.