Abstract:Soybean is a globally-important crop plant that supplies edible oil and plant protein. Drought is one of the most important abiotic stresses decreasing the growth and yield in soybean. In order to study the response under drought stress conditions, evaluation of drought resistance at multiple growth stages (germination, seedlings, whole growth period) was conducted in 253 soybean germplasm resources. Morphological indicators such as root length, plant height, 100-seed weight were measured, and stressful indicators such as germination rate, repeated drought survival rate, and enhanced drought resistance coefficient were calculated. The drought resistance evaluation index, which reflected the drought resistance of soybean germplasm resources, had been identified through correlation analysis and regression analysis. The drought stress treatment resulted in dramatic decrease on the measured index value (10.27%-96.62%), and significant difference if compared with that of the normal irrigation treatment (P<1.6E-09) was observed. No significant correlation between the values of drought resistance at multiple growth periods was detected. These germplasm accessions showing late maturity showed better performance on drought resistance to that of late maturing accessions. The drought resistance indexes qualified for the germination period (germination rate), the seedling period (survival rate of repeated drought) and the whole growth period (the number of pods per plant, the number of seeds per plant, the grain weight per plant and the biomass per plant) have been identified. Seven elite accessions, which showed extremely strong or strong drought resistant under three treatment conditions were obtained, and fifty accessions at two treatment conditions were obtained. Collectively, this study provided theoretical guidance and germplasm resource for deciphering drought resistance basis and identifying the elite parental lines used for soybean breeding.