Screening of Soybean Drought Resistance Phenotypic Index and Evaluation of Drought Resistant Resources

In order to explore the evaluation indexes and evaluation methods of phenotypic traits for rapid identification of drought resistance of soybean resources, we set up normal irrigation and drought treatments, used 122 soybean resources in Huang-Huai-Hai region to study the effects of drought stress on main agronomic characters of soybean and its variation, selection of high efficient drought resistance evaluation phenotypic index characters. The results showed that the variation of biomass yield was the largest under drought stress, followed by the seeds number per plant, plant height, yield per plant, pods number per plant, growth period, 100-seed weight and effective branching number. The total variation of the first five characters accounting for 90.25% of the total variation of the eight characters, and the inhibition rates of drought to the characters were 43.89%, 43.29%, 40.36%, 39.66%, 28.13%, 19.70%, 6.77% and 4.02%, respectively. Through the analysis of variance, coefficient of variation, difference and drought resistance index under the conditions of flood and drought, the yield, biological yield, pods number per plant and plant height were established as the evaluation indexes of drought resistance, which provided a simple and effective phenotypic index for drought resistance evaluation. In comparison with Jindou 21, based on these four evaluation indicators, calculated the standard drought resistance index, and according to the five-level drought resistance classification method, five high drought-resistant materials（Fendou 92, Shidou 658, Shidou 111, Fu 02-1 and Zhou 09013-1-1）, and eleven middle-high drought-resistant varieties were evaluated by this comprehensive drought-resistant index method.