榕江茶种质资源表型性状多样性及相关分析

Diversity and correlation analysis of phenotypic traits in Camellia yungkiangensis H.T.Chang germplasm resources

【目的】分析贵州特异茶资源即榕江茶(Camellia yungkiangensis)的表型性状遗传多样性及其相关性,为深入研究该资源的起源与演化奠定基础,也为该资源的优良基因挖掘及优异种质创新利用与保护提供参考。【方法】以118份榕江茶种质资源为研究对象,对其19个表型性状进行测定,并通过遗传变异分析、相关分析、主成分分析和聚类分析进行综合评价,探讨其遗传多样性和亲缘关系。【结果】118份榕江茶种质资源的树姿多为直立或半披张,树型多为灌木,叶部特征以叶色绿色、叶尖渐尖、叶基楔形、叶身平展、叶面平滑、叶缘平展、叶质较硬、叶齿密度中等、叶齿深度较浅的中叶型为主。13个质量性状的多样性指数为0.33~1.07,平均为0.66,变异系数为20.06%~66.83%,平均为40.56%;6个数量性状的多样性指数为1.74~2.09,平均为2.00,变异系数为8.20%~23.92%,平均为14.37%。19个表型性状的相关分析结果显示,呈极显著正相关的有14对性状,呈显著正相关的有10对性状,呈极显著负相关的有4对性状,呈显著负相关的有9对性状。主成分分析结果表明,前7个主成分特征值均大于1.000且累积贡献率达69.515%,包含了原始变量的绝大部分信息。以因子得分系数矩阵求得每个种质资源的叶片表型性状在各主成分上的综合得分,筛选出了13份叶片综合得分高的种质资源。聚类分析结果显示,在欧式距离为17.5处,可将供试的118份榕江茶种质资源分为七大类群,第Ⅰ大类群包含83份资源;第Ⅱ类群包含5份资源;第Ⅲ类群包含4份资源;第Ⅳ类群包含12份资源;第Ⅴ类群包含6份资源;第Ⅵ类群包含7份资源;第Ⅶ类群包含1份资源。【结论】榕江茶种质资源的表型性状具有丰富的遗传多样性,在特异性茶树新品种选育与种质创新上具有较大的利用潜力,13份叶片综合得分高的种质资源可用于品种选育。

【Objective】The morphological characteristics genetic diversity and the correlations of Rongjiang tea(Camellia yungkiangensis H.T.Chang),an exotic tea resource in Guizhou,were analyzed.It would not only lay the foundation for future in-depth research on the origin and evolution of this resource,but also provide reference for its excellent gene mining,innovative utilization and conservation.【Method】In this study,118 C.yungkiangensis germplasm resources were used to determine 19 phenotypic traits.Through analyzing their genetic variation,correlation,principal components and clustering,their genetic diversity and affinities could be studied.【Result】The plant shapes under study were mostly upright or semi-open,the plant types were mostly shrubs,and the leaf characteristics were mainly medium leaf types with green leaf color,acuminate leaf tip,cuneate leaf base,spreading leaf body,smooth leaf surface,spreading leaf edge,hard leaf texture,medium density of leaf teeth,and shallow depth of leaf teeth.The values of diversity index for 13 qualitative traits ranged from 0.33 to 1.07 with an average of 0.66,and the coefficient of variation ranged from 20.06%to 66.83%with an average of 40.56%;the values of diversity index for 6 quantitative traits were 1.74-2.09 with an average of 2.00,and the coefficient of variation ranged from 8.20%to 23.92%with an average of 14.37%.The results of correlation analysis of 19 morphological traits of the study subjects showed that 14 pairs of traits were highly significantly positively correlated,10 pairs were significantly positively correlated,4 pairs were highly significantly negatively correlated,and 9 pairs were significantly negatively correlated.Principal component analysis showed that the first 7 principal components had eigenvalues greater than 1.000 and a cumulative contribution of 69.515%,containing most of the information of the original variables.The comprehensive scores of leaf phenotypic traits of each germplasm resource on each principal component were obtained by the factor score coefficient matrix,and 13 germplasm resources with high comprehensive leaf scores were selected.According to the cluster analysis,the 118 C.yungkiangensis germplasm resources could be divided into 7 clusters at the Euclidean distance of 17.5,with theⅠcluster containing 83 resources;theⅡcluster containing 5 resources;theⅢcluster containing 4 resources;theⅣcluster containing 12 resources;theⅤcluster containing 6 resources;theⅥcluster containing 7 resources;theⅦcluster containing 1 resources.【Conclusion】The germplasm resources of C.yungkiangensis are rich in genetic diversity and have great potential to be used in the selection and breeding of new tea varieties and germplasm innovation.The 13 germplasm resources with high comprehensive leaf scores can be used in variety breeding.