Abstract

Phalaenopsis zhejiangensis is a rare and endangered plant species with extremely small populations. The complete chloroplast (cp) genome of P. zhejiangensis was assembled, its structural organization was described and comparative genomic analyses was carried out. The cp genome of P. zhejiangensis is 143,547 bp in length, with a GC content of 37.2%, which includes a pair of inverted repeats (IRs) of 24,464 bp separated by a small single-copy region of 10,764 bp and a large single-copy region of 83,856 bp. The cp genome contains 126 genes, consisting of 80 protein-coding genes, 38 transfer RNAs, and eight ribosomal RNAs. Six protein-coding genes, including ψndhB (two copies), ψndhD, ψndhG, ψndhK, and ψndhI, are identified as pseudogenes. Another six ndh genes, ndhA, ndhC, ndhE, ndhF, ndhH, and ndhJ, are missing from the plastid genome. A total of 41 cp simple sequence repeats (SSRs) were identified, including 40 mono-nucleotides and one di-nucleotides. Phylogenic analysis revealed P. zhejiangensis was nested inside the Phalaenopsis species and sister to P. wilsonii. The assembly and analysis of P. zhejiangensis cp genome will provide essential data for further study of taxonomy and systematics of Orchidaceae.

摘要

浙江蝴蝶兰是一种种群数量极少的珍稀濒危植物。组装了浙江松的完整叶绿体 (cp) 基因组，描述了其结构组织，并进行了比较基因组分析。P. zhejiangensis cp 基因组长度为 143,547 bp，GC 含量为 37.2%，其中包括一对 24,464 bp 的反向重复（IRs），由一个 10,764 bp 的小单拷贝区域和一个大的单拷贝区域隔开。 83,856 bp 的复制区域。cp 基因组包含 126 个基因，包括 80 个蛋白质编码基因、38 个转移 RNA 和 8 个核糖体 RNA。6个蛋白质编码基因，包括ψndhB（两个拷贝）、ψndhD、ψndhG、ψndhK和ψndhI被鉴定为假基因。又过了NDH基因，ndhA，ndhC，ndhE，ndhF，ndhH和ndhJ，从质体基因组缺失。共鉴定出 41 cp 简单序列重复 (SSR)，包括 40 个单核苷酸和 1 个双核苷酸。系统发育分析表明，P. zhejiangensis嵌套在蝴蝶兰种内，是P. wilsonii 的姐妹。浙江松的组装与分析 cp基因组将为进一步研究兰科的分类学和系统学提供重要数据。