广东苦茶资源嘌呤生物碱含量分析与评价

Analysis and Evaluation of Purine Alkaloid Contents in Bitter Tea Germplasm Resources from Guangdong

以13份广东省境内收集的苦茶资源为研究对象,来自不同省份的28份代表性品种(系)为对照,分析苦茶资源中嘌呤生物碱含量特征。结果显示,咖啡碱、可可碱、苦茶碱及生物碱总量均表现出较大的遗传差异,遗传多样性指数(H′)为0.78~1.94,变异系数(CV)为34.89%~191.19%。系统聚类分析将试验材料分为6个类群,类群Ⅰ、Ⅱ、Ⅲ主要为常规品种(系),咖啡碱是其优势嘌呤碱;类群Ⅴ为低咖啡碱的南昆山毛叶茶;类群Ⅳ、Ⅵ全部为苦茶资源,苦茶碱含量较高。通过综合评价,从苦茶资源中筛选出生物碱含量特异的育种材料10份。此外,不同叶位含量分析表明,苦茶中苦茶碱随叶片成熟度增加呈缓慢降低趋势,至成熟叶期仍维持较高水平。研究结果为今后嘌呤生物碱含量特异的功能性苦茶品种培育及开发利用提供了依据。

The purine alkaloids of 13 bitter tea germplasms from Guangdong Province along with 28 representative cultivars(lines)from different tea producing areas in China were selected for analysis in this paper.The results indicate that genetic diversity index(H′)of purine alkaloids ranged from 0.78 to 1.94,while the coefficient of variation(CV)ranged from 34.89%to 191.19%.The samples could be divided into 6 groups based on cluster analysis:groupⅠ,ⅡandⅢwere predominantly consisted of conventional cultivars with high caffeine content;groupⅤcontained caffeine-free cultivars from Nankun Mountain,while all samples in groupⅣandⅥwere bitter tea with high theacrine content.A total of 10 purine alkaloid specific bitter tea resources were identified.Moreover,theacrine showed a gradually decrease trend with the increase of leaf positions but maintained a high level in mature leaves of bitter tea.Taken together,our research provided a basis for genetic improvement of functional tea cultivars with specific purine alkaloids in the future.