基于表型参数及SRAP标记的广东茶树种质遗传多样性

Genetic diversity of Camellia sinensis germplasm in Guangdong Province based on morphological parameters and SRAP markers

采用表型鉴定与SRAP分子标记,对25份广东茶树种质和5份对照品种的遗传多样性进行系统评价和分类;利用Pearson相关和Farthest neighbor方法对其表型性状进行聚类分析.结果表明:茶树各性状的平均变异系数为32.15%,其中茸毛的变异系数最大,为42.41%;芽叶生育期变异系数最小,为18.52%.经基于表型性状的聚类分析,30份样本可分为4组:第1组有17个品种,第2组有10个品种,第3组为云南大叶种和凌云白毛茶2个对照品种,第4组仅海南大叶种1个对照品种.利用21对SRAP引物对茶树基因组DNA进行研究,共扩增出127条带,其中114条为多态性带,占88.67%;平均每个引物组合的谱带数和多态性带数分别为6.05条和5.43条.当遗传距离为0.39cm时,茶树种质可分成A、B、C3类,其中A类占83.33%;当遗传距离为0.31cm时,又可将A群划分为Ⅰ、Ⅱ、Ⅲ3个亚群,其中第Ⅰ亚群包括13个品种,第Ⅱ亚群包括2个品种,第Ⅲ亚群包括10个品种.依据SRAP标记的聚类与表型性状的表现并不完全一致.

By the methods of phenotypic identification and SRAP makers amplification, the genetic diversity of twenty-five local tea cuhivars in Guangdong Province and five contrastive cultivars from other regions was assessed and classified, and the phenotypic traits of the cultivars were clustered by Pearson correlation and Farthest neighbor methods. The coefficient of variation of the phenotypic traits was averagely 32. 15%. Fine-hair had the highest coefficient of variation （42.41%）, while the growth period of bud leaves had the smallest one （ 18.52% ）. Based on the cluster analysis of phenotypic traits, the test 30 tea cuhivars could be clustered into 4 groups, 17 cuhivars in the first group, 10 cuhivars in the second group, 2 contrastive cultivars Yunnan-dayezhong and Lingyun- baimaocha in the third group, and 1 contrastive cuhivar Hainan-dayezhong in the fourth group. After the amplification with 21 SRAP primers, a total of 127 fragments were detected, among which, 114 fragments were polymorphic, accounting for 88.67% of the total. The amplified fragments and polymorphic fragments per primer combination were averagely 6. 05 and 5.43, respectively. At the genetic distance of 0. 39 cm, the tea cultivars could be classified into three groups A, B and C, and 83.33% of the cultivars were belonged to group A. At the genetic distance of 0.31 cm, group A could be further classified into three sub-groups Ⅰ , Ⅱ and Ⅲ, 13 cultivars in subgroup Ⅰ , 2 cultivars in subgroup Ⅱ , and 10 cuhivars in subgroup Ⅲ. It was not exactly the same between the clustering based on SRAP markers amplification and the performance of phenotypic traits.