Li Miao-Miao, Meegahakumbura Muditha K, Wambulwa Moses C, Burgess Kevin S, Möller Michael, Shen Zong-Fang, Li De-Zhu, Gao Lian-Ming
CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Science, Kunming, 650201, China.
Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Science, Kunming, 650201, China.
Plant Divers. 2023 Jun 8;46(2):229-237. doi: 10.1016/j.pld.2023.06.002. eCollection 2024 Mar.
Chinese Assam tea ( var. ) is an important tea crop with a long history of cultivation in Yunnan, China. Despite its potential value as a genetic resource, its genetic diversity and domestication/breeding history remain unclear. To address this issue, we genotyped 469 ancient tea plant trees representing 26 var. populations, plus two of its wild relatives (six and three populations of and , respectively) using 16 nuclear microsatellite loci. Results showed that Chinese Assam tea has a relatively high, but comparatively lower gene diversity ( = 0.638) than the wild relative . ( = 0.658). Clustering in STRUCTURE indicated that Chinese Assam tea and its two wild relatives formed distinct genetic groups, with considerable interspecific introgression. The Chinese Assam tea accessions clustered into three gene pools, corresponding well with their geographic distribution. However, NewHybrids analysis indicated that 68.48% of ancient Chinese Assam tea plants from Xishuangbanna were genetic intermediates between the Puer and Lincang gene pools. In addition, 10% of the ancient Chinese Assam tea individuals were found to be hybrids between Chinese Assam tea and . Our results suggest that Chinese Assam tea was domesticated separately in three gene pools (Puer, Lincang and Xishuangbanna) in the Mekong River valley and that the hybrids were subsequently selected during the domestication process. Although the domestication history of Chinese Assam tea in southwestern Yunnan remains complex, our results will help to identify valuable genetic resources that may be useful in future tea breeding programs.
中国阿萨姆茶（变种）是一种重要的茶树品种，在中国云南有着悠久的种植历史。尽管它作为一种遗传资源具有潜在价值，但其遗传多样性以及驯化/育种历史仍不清楚。为了解决这个问题，我们使用16个核微卫星位点对代表26个变种群体的469株古茶树进行了基因分型，另外还对其两个野生近缘种（分别为6个群体的大厂茶和3个群体的厚轴茶）进行了基因分型。结果表明，中国阿萨姆茶具有相对较高的基因多样性，但与野生近缘种大厂茶（基因多样性 = 0.658）相比相对较低（基因多样性 = 0.638）。STRUCTURE聚类分析表明，中国阿萨姆茶及其两个野生近缘种形成了不同的遗传群体，存在相当程度的种间基因渗入。中国阿萨姆茶的种质聚为三个基因库，与其地理分布高度吻合。然而，NewHybrids分析表明，来自西双版纳的68.48%的中国古代阿萨姆茶树是普洱和临沧基因库之间的遗传中间类型。此外，发现10%的中国古代阿萨姆茶个体是中国阿萨姆茶与大厂茶的杂交种。我们的结果表明，中国阿萨姆茶是在湄公河流域的三个基因库（普洱、临沧和西双版纳）中分别驯化的，并且在驯化过程中随后对杂交种进行了选择。尽管中国阿萨姆茶在云南西南部的驯化历史仍然复杂，但我们的结果将有助于识别可能对未来茶树育种计划有用的宝贵遗传资源。
