Data from: Worldwide core collections of tea (Camellia sinensis) based on SSR markers

Tea (Camellia sinensis (L.) O. Kuntze) is the world's most popular beverage crop. However, to date, no core collection has been selected from worldwide germplasm resources on the basis of genotype data. In this study, we analyzed 788 tea germplasm accessions using 23 simple sequence repeat (SSR) markers. Our population structure analysis divided the germplasms into a Japanese group and an exotic group. The latter could be divided into var. sinensis and var. assamica. The genetic diversity was higher in germplasms from China, Taiwan, India, and Sri Lanka than in those from other countries, and low in germplasms from Japan. Using the number of SSR alleles as a measure of genetic diversity, we developed a core collection consisting of 192 accessions and three subcore collections with 96, 48, and 24 accessions. Although the results might be affected by marker-selection bias, the core 192 collection adequately covered the range of variation of the 788 accessions in floral morphology, and the chemical composition of first-flush leaves. These collections will be powerful tools for breeding and genetic research in tea.

茶树（Camellia sinensis (L.) O. Kuntze）是全球最受欢迎的饮料作物。然而迄今为止，学界尚未基于基因型数据从全球茶树种质资源中筛选得到核心种质集合。本研究利用23个简单序列重复（Simple Sequence Repeat, SSR）标记对788份茶树种质材料进行了遗传分析。群体结构分析将供试种质划分为日本类群与外来类群，后者可进一步分为茶变种（var. sinensis）与阿萨姆茶变种（var. assamica）。遗传多样性分析结果显示，中国、中国台湾地区、印度及斯里兰卡的种质资源遗传多样性高于其他国家，而日本的种质资源遗传多样性较低。本研究以SSR等位基因数量作为遗传多样性评价指标，构建了包含192份材料的核心种质集合，以及分别包含96、48、24份材料的3个亚核心种质集合。尽管该结果可能受标记选择偏倚的影响，但192份的核心种质集合充分覆盖了788份供试材料在花形态与首采叶化学成分上的变异范围。上述种质集合将为茶树育种与遗传研究提供有力工具。