Abstract:

Twenty-one quantitative characters（weight of single fruit，stone weight，a thouthand kernel weight，total sugar content，titratable acid content，etc.）of Ziziphus jujuba Mill. var. spinosa（Bunge）Hu ex H. F. Chow fruits'genetic variation rule and genetic diversity were studied in 393 wild jujube germplasm from follow provinces of Hebei，Liaoning，Shandong，Shaanxi．The results showed that the wild jujube germplasm was rich in genetic diversity. The obvious variety was observed with18 quantitative characters. The Shannon's index of the 18 quantitative characters exceeded 1.0. The degree of genetic diversity between various regions was distinctly different，and the upper-to-lower order of the various regions based on Shannon's index was Xingtai（H' = 1.198），Handan（H' = 1.147），Chaoyang（H' = 1.120），Baoding（H' = 1.069），Yulin（H' = 0.953），and Tai'an（H' = 0.733）. Cluster analysis divided the wild jujube germplasm into three groups，North China，Shaanxi，Liaoning. The wild jujube germplasm in North China（mainly represented by Xingtai）was the richest in quantitative diversity，which provides a wealth of material to choose for the breeding. The principal component analysis on quantitative characters result showed that the accumulative contribution rate of the first four principal components accounted for 71.85% in the total variation accounted，and the first principal component mainly reflected the fruit mass and a thouthand kernel weight，while the second principal component reflected the titratable acid content. The third and fourth principal component reflected stone vertical diameter and vitamin C content，respectively.

Key words: Ziziphus jujuba, germplasm, genetic diversity, cluster analysis, principal component analysis