越南槐叶绿体基因组序列特征与系统发育分析

Chloroplast Genome Sequence Characteristics and Phylogenetic Analysis of Sophora tonkinensis L.

越南槐(Sophora tonkinensis)是豆科苦参属的一种灌木,具有重要的药用价值和生态功能。由于其野生种群濒临灭绝,迫切需要对其进行保护。此外,对于市场需求而言,野生越南槐资源非常有限,市场上存在许多掺假产品。因此,需要建立一种在分子水平上鉴定越南槐及其掺假品的方法。叶绿体基因组是系统发育分析、遗传多样性评价和植物分子鉴定的重要遗传标记来源。在本研究中,我们报道了越南槐的叶绿体全基因组。结果显示,越南槐叶绿体基因组全长152234 bp,共编码126个基因即8个rRNA基因,37个tRNA基因,80个CDs基因和1个假基因(rps16),GC含量为36.40%。重复序列分析共检测到68个复杂重复序列和145个简单重复序列。边界分析结果显示,在越南槐中由于IR区的微收缩,导致JLA边界的rpl2和trnH基因丢失。核苷酸多态性分析共检测出3个变异热点区(trnT-GGU-psbD,rps18-rpl20和trnA-UGG-trnI-GAU),pi(π)>0.05。基于76个蛋白质编码基因序列的系统发育分析结果显示,苦参属物种聚为一个单系支,支持率达100%。本研究对越南槐及其近缘种的比较分析将有助于制定有效的保护和管理策略,并为这一重要药用植物的分子鉴定方法提供依据。

Sophora tonkinensis is a shrub of the genus Sophora in the Fabaceae family,known for its significant medicinal value and ecological importance.Due to the endangered status of wild populations,urgent measures are needed for its protection.Furthermore,owing to market demand,the resources of wild S.tonkinensis are highly limited,resulting in many counterfeit products in the market.Hence,there is a need to establish a molecular-level method for identifying S.tonkinensis and its adulterants.The chloroplast genome is an important genetic marker source for phylogenetic analysis,genetic diversity assessment,and molecular identification of plants.In this study,we report the complete chloroplast genome of S.tonkinensis.The complete chloroplast genome has a length of 152234 bp and a total GC content of 36.40%.It includes a total of 126 annotated genes,comprising 8 rRNA genes,37 tRNA genes,80 protein-coding genes and one pseudogene(rps16).A total of 68 complex repeat sequences and 145 simple repeat sequences were detected.The results of boundary analysis showed that rpl2 and trn H genes at JLA boundary were lost due to due to the IR contraction.Three divergence hotspots(trnT-GGU-psbD,rps18-rpl20 and trnA-UGG-trnI-GAU)were detected by nucleotide polymorphism analysis,with pi(π)>0.05.Phylogenetic analysis based on 76 protein-coding gene sequences showed that the genus Sophora was clustered into a lineage,with a support rate of 100%.The comparative analysis of S.tonkinensis and its closely related species in this study will contribute to the development of effective conservation and management strategies and provide a molecular identification methods for this important medicinal plant.