Abstract:This study attempted to identify the seedling drought resistance of RILs population from an indica and japonica crossing lines. A population of 120 recombinant inbred lines (RILs), which were derived from a cross between an elite indica cultivar IR29 and a drought-resistant japonica line ZD15, were used. An artificial drought stress was mimicked by PEG-6000 treatment. These parameters including the germ length and coleoptile length at germination stage, as well as the root length, root-shoot ratio, shoot fresh weight, root fresh weight, shoot dry weight and root dry weight at seedling stage, were measured. With the principal component analysis and membership function method, an objective comprehensive evaluation value (D value) of drought resistance was obtained. According to the D value, the 122 rice lines (or variety) were divided into three groups. The groupⅠcontaining 33 lines with D value between 0.201 and 0.400, was a drought sensitive group. The groupⅡcontaining79 lines with D value between 0.401 and 0.600, was a moderate drought resistant group. The last group containing 10 lines with D value between 0.601 and 0.800, was a drought resistant group. Using stepwise regression and principal component analysis, these eight traits were selected to be evaluation indicators for drought resistance at seedling stage of rice. Taken together, the drought-resistant lines selected in this study can be further cultivated as breeding intermediate materials, or used as breeding resources to enrich the rice breeding resource in Ningxia.