Preliminary study on drought resistance of alfalfa seedling under water stress

Based on 15 morphological and physiological indexes, 22 different alfalfa cultivars and population from America, Australia, Canada and China were evaluated synthetically under water stress in seedling period through principal component analysis and cluster analysis. 15 drought-resistance indexes were simplified into 5 principal components. Based on these 5 principal components, the 22 cultivars were clustered into 3 groups. Their levels of drought resistance were strong, medium and weak respectively.