草甸退化指示植物黄帚橐吾的质体基因组特征

Plastome of Ligularia Virgaurea,an Indicator Species of Alpine Meadow Degradation

黄帚橐吾是青藏高原高寒草甸生态系统广泛分布的毒杂草。在过度放牧的干扰下,黄帚橐吾功能性状适应作用还不清楚。为了解黄帚橐吾叶绿体基因组特征,本研究分析了其叶绿体基因组结构和基因构成特征,并进行系统演化基因组分析。结果表明:(1)黄帚橐吾叶绿体基因组的功能基因有134个,其中包括8个rRNA基因、37个tRNA基因和89个蛋白编码基因。(2)在黄帚橐吾叶绿体基因组的密码子组成中,RSCU值>1的密码子有30个,其中以A/U碱基结尾的有27个;RSCU值<1的密码子有32个,其中以G/C碱基结尾的密码子偏多,为29个。(3)在黄帚橐吾的叶绿体基因组中,检测出37个散在重复序列,包括17个正向重复序列和18个回文重复序列;检测到42个SSR位点。(4)通过最大简约法(MP)对黄帚橐吾及其近缘类群共计12个物种质体基因组构建系统发育树,结果显示黄帚橐吾可能是橐吾属中比较古老的物种。从而在分子层面更多地认识黄帚橐吾的遗传背景和种质资源鉴定,为环境适应性分析提供理论支持。

Ligularia virgaurea is a poisonous weed widely distributed in alpine meadow ecosystem of QinghaiTibet Plateau.Under the disturbance of overgrazing,the adaptive role of L.virgaurea through functional traits is still unclear.In this study,Characterization of plastome of L.virgaurea were analyzed and the phylogenetic genomic analysis was conducted.The results showed that:(1)A total of 134 functional genes were annotated,including 8 rRNA genes,37t RNA genes and 89 protein coding genes.(2)In the chloroplast genome of L.virgaurea,30 codons with RSCU value>1were found,and 27 condons with A/U base ending;32 condons with RSCU value<1,and 29 condons ending in G/C.Codons of the chloroplast genome of L.virgaurea was more inclined to end in G/C base.(3)A total of 37 scattered repeats,including 18 forward repeats and 19 palindromic repeats were detected in the chloroplast genome of L.virgaurea,and 42 SSR loci were detected.(4)Phylogenetic trees were constructed from the plastid genomes of 12 species of L.virgaurea and its allies by the method of maximum parsification(MP).The results showed that L.virgaurea might be an old species in genus Ligularia.This study provides a theoretical basis for environmental adaptability analysis,and learns more about the genetic background and germplasm identification of L.virgaurea at the molecular level.