Insights into the genetic relationships and breeding patterns of the African tea germplasm based on nSSR markers and cpDNA sequences

Africa is one of the key centers of global tea production. Understanding the genetic diversity and relationships of cultivars of African tea is important for future targeted breeding efforts for new crop cultivars, specialty tea processing, and to guide germplasm conservation efforts. Despite the economic importance of tea in Africa, no research work has been done so far on its genetic diversity at a continental scale. Twenty-three nSSRs and three plastid DNA regions were used to investigate the genetic diversity, relationships, and breeding patterns of tea accessions collected from eight countries of Africa. A total of 280 African tea accessions generated 297 alleles with a mean of 12.91 alleles per locus and a genetic diversity (HS) estimate of 0.652. A STRUCTURE analysis suggested two main genetic groups of African tea accessions which corresponded well with the two tea types Camellia sinensis var. sinensis and C. sinensis var. assamica, respectively, as well as an admixed “mosaic” g...非洲是全球茶叶生产的核心产区之一。解析非洲茶树品种的遗传多样性与亲缘关系，对于未来开展针对性的茶树新品种选育、特色茶叶加工，以及指导种质资源保护工作均具有重要意义。尽管茶叶产业在非洲经济中占据重要地位，但目前尚无针对非洲大陆尺度的茶树遗传多样性相关研究。本研究采用23个核简单序列重复（nSSRs，nuclear Simple Sequence Repeats）标记与3个质体DNA区域，对采自非洲8个国家的280份茶树种质资源的遗传多样性、亲缘关系及选育模式展开分析。本次研究共获得297个等位基因，各位点平均含12.91个等位基因，遗传多样性（HS）估值为0.652。STRUCTURE群体结构分析结果显示，非洲茶树种质可划分为两个主要遗传类群，分别与茶树（Camellia sinensis var. sinensis）和阿萨姆茶（C. sinensis var. assamica）两个变种高度吻合，同时还存在一个混合的“镶嵌”类群（原文内容未完整呈现）。