基于SSR标记的‘天山菜茶’遗传多样性和亲缘关系分析

Analysis of Genetic Diversity and Relationship of ‘Tianshancaicha’ Germplasm Resources Based on SSR Markers

摘要:

为探究茶树‘天山菜茶’(Camellia sinensis ‘Tianshancaicha’)种质资源的遗传多样性，以宁德市其他产区的地方茶树种质资源为参照，采用SSR分子标记技术对143份种质资源进行分子标记，分析‘天山菜茶’种质资源的遗传背景及其与参照茶树种质资源的亲缘关系。结果表明，6对引物共扩增出55个等位基因，平均9.166个；观测杂合度平均值为0.649；期望杂合度平均值为0.779；Shannon指数平均值为1.870；PIC平均值为0.742；遗传聚类分析将不同产区的143份种质资源分为5个类群，其中112份‘天山菜茶’种质资源(含蕉城野生苦茶树)分散在各个类群中，说明其可能同属‘闽东菜茶’的遗传背景；不同产区间基因流为2.225，表明‘闽东菜茶’之间的基因交流性较强。‘天山菜茶’种质资源间存在交叉遗传现象，遗传差异较大，遗传多样性较丰富，可辅助核心和优异资源筛选。

Abstract:

To explore the genetic diversity of Camellia sinensis ‘Tianshancaicha’ germplasm resources, the genetic background of 143 ‘Tianshancaicha’ germplasm resources and their genetic relationship were analyzed by using SSR molecular marker technology, with local tea tree germplasm resources from other production areas in Ningde City as references. The results showed that 6 pairs of primers amplified a total of 55 alleles, with an average of 9.166; the average observed heterozygosity, expected heterozygosity, Shannon index and PIC were 0.649, 0.779, 1.870 and 0.742, respectively. The 143 germplasm resources from different production areas could be divided into 5 groups by genetic cluster analysis. Among them, 112 ‘Tianshancaicha’ germplasm resources (including wild bitter tea trees in Jiaocheng) were scattered in different groups, indicating that they might share the same genetic background as ‘Mindencaicha’. The gene flow among different production areas was 2.225, suggesting that the gene exchange among ‘Mindencaicha’ was relatively strong. So, there was a phenomenon of cross-inheritance among the ‘Tianshancaicha’ germplasm resources, with significant genetic differences and rich genetic diversity, which can assist in the selection of core and excellent resources.