信阳10号叶绿体基因组及其系统进化

信阳10号是适制信阳毛尖的国家级良种,然而其起源以及与其他茶树品种之间的进化关系尚不清晰。利用MGI2000平台对信阳10号进行测序,组装获得了信阳10号的完整叶绿体基因组并对其结构进行分析,同时,为探究信阳10号与其他茶树的进化关系,构建了46个物种的叶绿体基因组系统发育树。结果表明：（1）信阳10号叶绿体基因组大小为157 041 bp,包括2个反向重复区（IR,26 078 bp）,1个大单拷贝区（LSC,86 594 bp）和1个小单拷贝区（SSC,18 291 bp）;共注释得到叶绿体基因113个,包括79个蛋白质编码基因,30个tRNA基因和4个rRNA基因。（2）在信阳10号的叶绿体基因组中共检测到了74个SSR位点,大部分SSR由A/T组成。（3）贝叶斯法构建的系统进化关系树显示,信阳10号与福建铁罗汉关系最近,并且两者的叶绿体基因组完全相同,推测可能来源于相同母本;信阳10号与韩国茶Chamnok和Sangmok、福建白鸡冠、云南德宏茶也有较近的亲缘关系。研究结果为进一步探究茶树起源与演化以及分子育种提供了基础。

Complete Chloroplast Genome of Camellia sinensis cv. Xinyang 10 and Its Phylogenetic Evolution

Camellia sinensis cv. Xinyang 10 is a national excellent cultivar suitable for producing Xinyangmaojian. However, its origin and evolutionary relationship with other tea cultivars are still unknown. This study obtained the complete chloroplast genome of C. sinensis cv. Xinyang 10 by using MGI2000 sequencing platform, and then analyzed the chloroplast genome structure. A chloroplast genome phylogenetic analysis of 46 species was also conducted to infer the position of C. sinensis cv. Xinyang 10. The results show that: (1) the chloroplast genome of Xinyang 10 is 157 041 bp in length, including a pair of inverted repeat regions (IR, 26 078 bp), a large single-copy region (LSC, 86 594 bp) and a small single-copy region (SSC, 18 291 bp). A total of 113 genes are annotated, including 79 protein-coding genes, 30 tRNA genes, and 4 rRNA genes. (2) 74 SSR loci were detected in the chloroplast genome of Xinyang 10, most of the SSRs were composed of A/T. (3) The cluster analysis using Bayesian method shows that Xinyang 10 had the closest genetic relationship with C. sinensis cv. Tieluohan. Both cultivars may share the same female parent as their chloroplast genomes were identical. Xinyang 10 also had a close relationship with two Korean tea (Chamnok and Sangmok), Baijiguan and C. sinensis var. Dehungensis. The results provided a basis for further research on the origin and evolution of tea and molecular breeding.