Analysis of the Principal Components and the Subordinate Function of Lolium perenne Drought Resistance Cold Resistance and Related Physiological Indexes Identification of Bupleurum Seedlings during Wintering Stage Analysis of the Principal Components and the Subordinate Function of Alfalfa Drought Resistance Analyses of the Subordinate Function and the Principal Components of Hosta Drought Resistance Subordinate function and principal component analysis of salt tolerance of seedlings germinated from microtubers of Jiangxi local yam Morphological indexes of drought resistance identification in rice Physiological Response and Comprehensive Evaluation of Cold Resistance under Cold Stress for Different Varieties of Olea europaea