Abstract: 【Objective】 In order to provide information of processing apple varieties (Malus domestica Borkh.) and offer theoretical reference for breeding of processing apple. 【Method】 Genetic diversity of 18 processing and 2 fresh apple varieties were evaluated with 12 simple sequence repeats (SSR) primer pairs previously identified in apple, using cluster analysis and principal coordinate analysis (PCO). 【Result】All the varieties were divided into 4 groups by cluster analysis. High-acid variety Avrolles formed a single group with GS less than 0.42 with other varieties. The second group contained Longfeng and Dolgo from Northeast of China, inheriting Chinese crab apple genes. The 5 cider varieties with high tannin content were clustered into the third group, i.e., Dabinette, Frequin rouge, Kermerrien, Marie Menard, Douce.Coetligne. The fourth group was mainly composed of 12 juice and table apple varieties. The genetic similarity (GS) of the cluster analysis varied from 0.14 to 0.83. Principal coordinate analysis also divided all the varieties into four groups. Both analyses indicated there were genetically abundant diversities among apple processing varieties. 【Conclusion】 There were much difference between cider and juice varieties, cider and table varieties as well as Chinese crab apple and western European crab apple, while juice and table apple varieties had similar genetic background.

Key words: Apple (Malus domestica Borkh.), Processing varieties, Genetic diversity, Simple sequence repeats, Cluster analysis, Principal coordinate analysis