Analysis of genetic diversity of processing apple varieties

Chinese. 增进对加工专用苹果品种的了解，为加工苹果育种提供依据。利用12对微卫星（SSR）标记，通过聚类分析和主坐标分析，研究了18个苹果加工品种和2个鲜食品种的遗传差异。聚类分析结果将供试品种分为4大类群，第1类是高酸品种酸王，该品种与其它加工品种相似系数均小于0.42；第2类是龙丰和铃铛果，都含有中国小苹果的遗传因子；第3类包括大比耐、苦绯甘、苦开麦、美那和甜格力，都是单宁含量高的酿酒品种；第4类包括12个品种，主要是制汁品种和鲜食品种。各品种的相似系数分布在0.14～0.83之间。利用主坐标分析也将供试品种分为4大类群。两种分析都表明，加工品种之间存在丰富的遗传多样性。酿酒品种与鲜食及制汁品种之间、中国小苹果与西欧小苹果之间有较大的遗传差异，而制汁品种与鲜食品种的遗传背景较为接近。

English. In order to provide information of processing apple varieties (Malus domestica Borkh.) and offer theoretical reference for breeding of processing apple. 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). 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. 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.