湖南莽山茶树种质资源调查与品质性状的遗传多样性分析

为了解湖南莽山茶树资源遗传多样性,本研究调查和收集了33份湖南莽山茶树资源,对其中的24份资源进行了生物学性状考察,27份资源进行了品质成分分析。结果表明,24份资源树型多为小乔木,树姿多为直立状,芽叶多为无茸毛或少茸毛,芽叶色泽淡绿色或黄绿色,叶色绿色或深绿,叶片锯齿密度中或稀、锐度中,叶缘平,叶面微隆起,叶尖渐尖,叶质中,12个性状的变异系数为38.07%~77.90%,平均值为58.70%,遗传多样性指数为0.51~1.05,平均值为0.81。27份资源的18项品质成分变异系数在4.86%~71.32%之间,平均值为28.29%;多样性指数在1.59~2.03之间,平均值为1.86;主成分分析表明,前5个主成分累计贡献率达84.36%;通过聚类分析将27份资源聚为5大类群,类群Ⅰ含15份资源并分为了2个亚群,类群Ⅱ含5份资源,类群Ⅲ含5份资源,类群Ⅳ和类群Ⅴ各包含1份资源;初步筛选出1份低咖啡碱资源和3份高咖啡碱资源。本研究为湖南莽山茶树资源挖掘与利用以及湖南茶树演变研究奠定了基础。

Germplasm Resources and Genetic Diversity of Quality Characters of Tea Plants from Mangshan in Hunan

Thirty three tea plant resources from Mangshan in Hunan province were investigated and collected,24 of which were studied for biological characters and 27 of which were studied for quality analysis.The 24 resources were mainly small trees with upright habit.The young leaves were mostly glabrous or slightly pubescent,light green or yellow green in color,and the adult leaves were green or dark green,medium-sharply medium-dense-to sparse-serrated and flat at margin,with slightly raised upper surface,acuminate apex,and medium texture.The coefficient of variation of 12 characters ranged from 38.07%to 77.90%,with the average value of 58.70%,and the genetic diversity index was 0.51~1.05,with the average value of 0.81.The variation coefficient of 18 quality components of the 27 resources ranged from 4.86%to 71.32%,with an average of 28.29%;the diversity index ranged from 1.59 to 2.03,with an average of 1.86;the principal component analysis indicated that the cumulative contribution rate of the first 5 principal components was 84.36%.The resources were divided into 5 groups.Group I contained 15 resources,which were divided into two subgroups.Both Group II and Group III contained 5 resources,while Group IV and Group V contained 1 resource each.One low-caffeine and 3 high-caffeine tea plant resources were preliminarily screened out.This study provides a basis for the exploration and utilization of Mangshan tea plant resources and researches in the evolution of tea plants in Hunan province.