Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China.
Sci Rep. 2020 Nov 27;10(1):20782. doi: 10.1038/s41598-020-77661-3.
The six pinnate-leaved species are a very particular group in the genus Primula. In the present paper, we sequenced, assembled and annotated the chloroplast genomes of five of them (P. cicutarrifolia, P. hubeiensis, P. jiugongshanensis, P. merrilliana, P. ranunculoides). The five chloroplast genomes ranged from ~ 150 to 152 kb, containing 113 genes (four ribosomal RNA genes, 29 tRNA genes and 80 protein-coding genes). The six pinnate-leaved species exhibited synteny of gene order and possessed similar IR boundary regions in chloroplast genomes. The gene accD was pseudogenized in P. filchnerae. In the chloroplast genomes of the six pinnate-leaved Primula species, SSRs, repeating sequences and divergence hotspots were identified; ycf1 and trnH-psbA were the most variable markers among CDSs and noncoding sequences, respectively. Phylogenetic analyses showed that the six Primula species were separated into two distant clades: one was formed by P. filchnerae and P. sinensis and the other clade was consisting of two subclades, one formed by P. hubeiensis and P. ranunculoides, the other by P. merrilliana, P. cicutarrifolia and P. jiugongshanensis. P. hubeiensis was closely related with P. ranunculoides and therefore it should be placed into Sect. Ranunculoides. P. cicutarrifolia did not group first with P. ranunculoides but with P. merrilliana, although the former two were once united in one species, our results supported the separation of P. ranunculoides from P. cicutarrifolia as one distinct species.
六出叶组是报春花属中一个非常特殊的类群。本研究对该组的 5 个物种（多被银莲花、湖北银莲花、九龙山银莲花、美丽银莲花、展毛银莲花）的叶绿体基因组进行了测序、组装和注释。这 5 个叶绿体基因组大小在 150-152 kb 之间，包含 113 个基因（4 个核糖体 RNA 基因、29 个 tRNA 基因和 80 个蛋白质编码基因）。6 种六出叶报春花的叶绿体基因组在基因排列上具有很高的相似性，并且具有相似的 IR 边界区域。accD 基因在银莲花中发生了假基因化。在 6 种六出叶报春花的叶绿体基因组中，鉴定到了 SSRs、重复序列和变异热点；ycf1 和 trnH-psbA 分别是 CDNAs 和非编码序列中最具变异性的标记。系统发育分析表明，这 6 种报春花分为两个远缘分支：一个分支由银莲花和中国报春花组成，另一个分支由湖北银莲花和展毛银莲花组成，再分为两个亚分支，一个亚分支由美丽银莲花、多被银莲花和九龙山银莲花组成。湖北银莲花与展毛银莲花关系较近，应归入银莲花组 Sect. Ranunculoides。多被银莲花并没有首先与展毛银莲花聚在一起，而是与美丽银莲花聚在一起，尽管前两者曾被归为一个种，我们的结果支持将银莲花与多被银莲花分离开来，作为两个独立的种。
