中国山茶科植物区系及叶绿体基因组结构进化分析

Structure and Phylogeny of Chloroplast Genomes and Spermatophyte Flora in Chinese Theaceae

对中国种子植物属的分布区类型进行属的区系分析,并统计了中国不同地区山茶科植物的分布情况,以测序完成的14个属14种山茶科植物叶绿体基因组为研究对象,系统比较基因组间的结构差异,分析4个IR边界扩张与收缩情况,并以近缘物种圆叶鹿蹄草为外类群,使用MEGA 4.0构建系统进化树,分析物种间的亲缘关系。结果表明,我国山茶科植物共计15属,主要为热带亚热带成分的涉及9个属,占山茶科总分布包含属的60%。所分析的14种山茶科植物基因组长度各一,折柄茶属的心叶折柄茶叶绿体基因组最大,为158450 bp,而最小的柃木属翅柃大小为155179 bp,差异接近3.3 kb。以杜鹃目下鹿蹄草科的圆叶鹿蹄草为外类群,对14种山茶科植物构建了系统进化树,一共12个节点,支持率较高,山茶科14个种被分成2个大的进化枝,红皮紫茎和心叶折柄茶亲缘关系近,厚皮香属的厚皮香与山茶科的所属关系存在争议。结合植物区系分析与叶绿体基因组的结构进化分析方法,反映出山茶科植物的进化发育关系,为解决这类问题提供参考信息。

To obtain the flora type of Chinese Theaceae and the structural characteristics and evolutionary relationship of their chloroplast genomic genomes.Based on the results of areal-types of genera distribution types of Chinese seed plants divided by WU Zheng-yi,we analyzed and calculated the distribution of Theaceae in different parts of China,and studied the genomes of 14 species of Theaceae that had been sequenced,and systematically compared the structural differences between genomes.Four inverted repeat(IR)boundary expansion and contraction were analyzed,and the sibling species of Pyrola rotundifolia was used as an outgroup to build a systematic evolutionary tree by MEGA 4.0,so that the species-to-species kinship was compared.It was found that there existed a total of 15 genus of Theaceae in China,in which 9 were tropical and subtropical components,accounting for 60%of the total.There was a small difference among the chloroplast genome size,and the largest difference was 3.3 kb.The largest chlorophyll genome was Hartia cordifolia(158450 bp),while the smallest was Eurya alata(155179 bp).The phylogenetic tree of Theaceae which was based on P.rotundifolia.Had 12 nodes with high rate of supports.The tree exhibited good resolution to reflect the genetic relationships among Theaceae.Fourteen genera of Theaceae were mainly divided into two evolutionary branches,Stewartia rubiginosa and Hartia cordifolia showed close genetic relationship.The relationship of Ternstroemia gymnanthera with Theaceae was controversial relationship.Combined with the methods of spermatophyte flora and structural evolution analysis of chloroplast genome,the results of this study may provide a basis for further genetic studies and the development and utilization of Theaceae.