关键词: 李, 资源, 寒地, 表型性状, 遗传多样性

Abstract: In order to further understand the genetic diversity of plum germplasm resources，20 descriptive phenotypic traits of 96 samples were kept in Mudanjiang Branch of Heilongjiang Academy of Agricultural Sciences were evaluated according to the‘Plums germplasm resources description specification and data standard’. Sixteen quantitative phenotypic traits were analyzed by correlation analysis，cluster analysis，principal component. The results showed that a total of 66 variant types were observed for the 20 descriptive traits. Among them，the leaf shape，the color of the peel and the shape of the core had a large variation range. The Shannon-Wiener information index H and Simpson genetic diversity index D ranged from 0.3768 to 1.3993 and 0.2188 to 0.7196，respectively，and the higer diversity indexes were observed in fruit color（H：1.2093，D：0.6814）and leaf shape（H：1.1227，D：0.5484）. Among the 16 quantitative traits，the single fruit mass coefficient of variation was the largest，being 61.32%；the fruit shape index coefficient of variation was the smallest，8.72%. The 96 plum germplasm resources were divided into 3 groups at the Euclidean distance of 22 according to cluster analysis，the first group could be used for selecting freestone and high resistant cultivars. Group II could be used for selecting high resistant and high yield cultivars；Group III could be used for selecting large fruit，high edible rate and freestone cultivars. Principal component analysis showed that the cumulative contribution rate of the first five principal components reached to 78.191%，such as fruit vertical diameter，fruit transverse diameter，and 1 year twig diameter and so on，which mainly reflect the fruit size and twig trait factors. Fruit traits contributed the most to the phenotypic trait variation of plum germplasm resources in cold area，followed by traits of 1 year twig. Combined to the correlation analysis results，16 quantitative traits could be simplified into seven main indicators：fruit vertical diameter，fruit transverse diameter，leaf width，kernel transverse diameter，fruit shape index and 1 year twig diameter，which improved the efficiency for evaluation and breeding selection of plum germplasm resources in northeast cold area.

Key words: plum, germplasm, cold area, phenotypic trait, genetic diversity