Abstract:

To reveal the genetic diversity of albino tea cultivars （strains）， 23 tea germplasms （20 albino， 3 evergreen） were analyzed using 2b-restriction site-associated DNA （2b-RAD） sequencing. The genetic diversity， genetic relationship and population structure of 23 tea germplasms were analyzed. The results showed that 576 193 750 high-quality reads and 56 498 high-quality single nucleotide polymorphisms （SNPs） were obtained. The phylogenetic tree and principal component analysis showed that 23 tea germplasms were divided into 3 groups. GroupⅠhad 1 strain （Dayezhong） from Guizhou. Group Ⅱ had 6 germplasms originated from Guizhou local populations. GroupⅢhad 14 germplasms from Zhejiang， 2 germplasms from Anhui and Fujian， respectively. All genetic parameters of 3 groups based on the phylogenetic tree were showed group Ⅰ>groupⅡ>groupⅢ， and moderate and high genetic differentiation between group Ⅰ with groupⅡand group Ⅲ were observed， respectively. Generally， there was moderate or high genetic differentiation among albino tea cultivars （strains）， and the higher genetic differentiation was observed among germplasms from different geographical regions， which provided a theoretical basis for identification， utilization and breeding of albino tea plant （Camellia sinenis）.

Key words: albino tea plant, 2b-RAD, SNP, genetic diversity

摘要：

为揭示白化茶树品种（系）的遗传多样性，利用简化基因组测序技术（2b-restriction site-associated DNA，2b-RAD）对23份茶树种质（20份白化，3份常绿对照）进行测序，分析其遗传多样性、亲缘关系和群体结构。结果表明，共获得576 193 750条高质量测序数据和56 498个高质量SNPs。系统发育树和主成分分析表明，23份种质可分为3个类群，类群Ⅰ为1份来自贵州的大叶种，类群Ⅱ包含来自贵州的地方种质6份，类群Ⅲ包含来自浙江的14份种质和来自安徽、福建的2份种质。基于系统发育树，3个类群的遗传多样性参数均表现为：类群Ⅰ>类群Ⅱ>类群Ⅲ，类群Ⅰ和类群Ⅱ、类群Ⅲ之间分别呈现中、高度的遗传分化水平。综上所述，白化茶树品种（系）存在中、高度的遗传分化，不同地理来源的种质间遗传分化更大，为白化茶树种质鉴定、资源利用和育种等提供了理论依据。

关键词: 白化茶树, 2b-RAD, SNP, 遗传多样性