基于叶绿体基因组分析我国苜蓿属植物演化路径

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 基于叶绿体基因组分析我国苜蓿属植物演化路径 DOI: 10.5846/stxb202104241078 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 上海市自然科学基金(18ZR1425400) The Evolution Path of Medicago in China based on the Chloroplast Genome Analysis Author: Affiliation: Fund Project: Natural Science Foundation of Shanghai (18ZR1425400) 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:全球苜蓿属植物约87种,我国有15种,大多为广布种,可生活在不同的生境当中。该属植物由于荚果等形态变异复杂,繁育系统多样,其进化历史一直是本领域关注的热点问题之一。随着分子生态学的发展,利用基因组学的方法解决生态学问题不断报道,但目前我国苜蓿属物种的叶绿体基因组数据缺乏,有关其演化路径的研究尚少有开展。为此,选取了我国苜蓿属10个代表物种和胡卢巴属1种,测序比较其叶绿体基因组结构特征,基于叶绿体基因组和核ITS序列构建分析其系统发育关系,并结合物种地理分布生境特征探究我国苜蓿属植物的演化路径。结果显示,以上苜蓿属植物的叶绿体基因组大小为121-127 kb,均为非典型的"四区"结构,缺失反向重复区。在10个苜蓿属物种的叶绿体基因组中共检测到1,273个SSR位点,这些SSR位点可以作为潜在的分子标记用于我国苜蓿属植物资源的鉴定。供试苜蓿属物种的叶绿体基因组共发生6次基因倒位。天蓝苜蓿的2个倒位发生在基因atpB到ycf3、ndhC到trnLUAA之间的区域;青海苜蓿和花苜蓿的叶绿体基因组共享4个倒位,分别位于基因psbM到psaA、ndhB到trnNGUU、ndhB到rpoA以及clpP到rpl20区间。天蓝苜蓿中还存在clpP、rpoC1和atpF基因内含子的丢失现象。基于叶绿体基因组及ITS序列构建的苜蓿属系统发育关系,支持传统上将苜蓿属划分为紫苜蓿组、南苜蓿组、阔荚苜蓿组和天蓝苜蓿组的分类处理。其中,直果胡卢巴、单花胡卢巴与毛荚苜蓿形成一支,位于系统树的基部,支持中国苜蓿属和胡卢巴属之间存在过渡类型"类苜蓿植物"的观点。分析我国苜蓿属植物的分化原因可能与这些物种的生境有关,特别是年平均温度可能是导致苜蓿物种分化的决定性因素。 Abstract:Medicago L. is a genus comprising approximately 87 species in the world, and 15 species in China. Most of them are widely distributed and can live in different habitats. Due to complex morphological variation such as pods, and diverse breeding systems, the evolutionary history of this genus has always been one of the hotspot. With the development of molecular ecology, the use of genomics to solve ecological problems has been continuously reported. However, the current chloroplast genome data of the genus of Medicago in China is still lacking, and the analysis of its evolution path has seldom carried out. In this study, ten Medicago species and one Trigonella species in China were selected to sequence and compare the structural characteristics of the chloroplast genomes. The phylogenetic relationship based on the chlroplast genome and nuclear ITS sequence were analyzed, and the evolution path were explored based on their geographical distribution and habitat characteristics. The results showed that the chloroplast genomes of the above species were 121-127 kb in size, all of which displayed atypical quadripartite structure missing one copy of the inverted repeat region (IR). Totally, 1,273 variable SSR loci were found in these Medcago species, which could be used as potential molecular markers to identify Medicago germplasms. There were 6 inversions happened in the chloroplast genome of the tested Medicago species. Two unique inversions were identified between genes atpB to ycf3, ndhC to trnLUAA in M. lupulina. And four inversions were shared by M. archiducis-nicolai and M. ruthenica between genes psbM to psaA, ndhB to trnNGUU, ndhB to rpoA, clpP to rpl20. Intron losses were also observed in clpP, rpoC1 and atpF genes in M. lupulina chlroplast plastome. The phylogenetic relationship based on chloroplast genome and ITS sequences supported the traditional classification to subdivide Chinese Medicago into section Medicago, Spirocarpos, Platycarpae and Lupularia. The basal position of the clade consisting of M. edgeworthii, M. orthoceras and M. monantha like the Trigonella supported the existence of ″Trigonelloid″ Medicago. The differentiation may be related to the habitats of these species, especially the annual average temperature may be the decisive factor leading to the differentiation of Medicago in China. 参考文献 相似文献 引证文献