基于ITS和trnL-F序列鉴定边陲黄耆为独立的物种  

Identification of Astragalus dshimensis Gontsh. as A Separate Species Based on ITS and trn L-F Sequences

作　　者：张杰[1,2] 张明理[1,3] 

机构地区：[1]中国科学院新疆生态与地理研究所,新疆乌鲁木齐830011 [2]中国科学院大学,北京100049 [3]中国科学院植物研究所,北京100093

出　　处：《干旱区研究》2017年第4期856-861,共6页Arid Zone Research

基　　金：科技部基础研究计划项目(2014CB954201);中国科学院新疆生态与地理研究所"百人计划"项目资助

摘　　要：乌拉特黄耆(Astragalus hoantchy Franch.)、边陲黄耆(A.dshimensis Gontsh.)和A.coluteocarpus Bioss.为形态上相似的3个近缘物种。为了明确它们之间的分子亲缘关系,探讨分子证据是否支持边陲黄耆为一个独立的物种,测定了这3个物种共33个样本的ITS和trn L-F序列。基于ITS+trn L-F联合序列,运用Mega 6.06软件计算了种内和种间的遗传距离,并利用Mega 6.06和Mr Bayes 3.2软件分别构建了最大似然(ML)树和贝叶斯(BI)树。结果显示:乌拉特黄耆、边陲黄耆和A.coluteocarpus Bioss.的种内平均遗传距离分别为0.000、0.001和0.003;乌拉特黄耆和边陲黄耆之间平均遗传距离为0.010,而这2个物种与A.coluteocarpus Bioss.之间的平均遗传距离分别为0.015和0.016;乌拉特黄耆和边陲黄耆种间的平均遗传距离远大于其物种内的遗传距离;ML树和BI树具有相似的拓扑结构,均分成了3个分支,其中每个物种的所有个体都聚集在一个单独的分支上且不存在种间交叉现象。本研究揭示了这3个近缘物种的分子亲缘关系,分子证据说明边陲黄耆应该是一个独立的种。Astragalus hoantchy Franch.,A. dshimensis Gontsh. and A. coluteocarpus Bioss. are three related species morphologically. In this study,the ITS and trn L-F sequences of 33 individuals of the three species were sequenced so as to explore their genetic relationship and whether A. dshimensis Gontsh. is a separate species or not.The intraspecific and interspecific genetic distances were calculated by Mega 6. 06,and the phylogenetic trees of Maximum Likelihood（ ML） method and Bayes Inference（ BI） method were respectively reconstructed by Mega 6. 06 and Mr Bayes 3. 2. The results showed that the intraspecific genetic distances of A. hoantchy Franch.,A. dshimensis Gontsh. and A. coluteocarpus Bioss. were 0. 000,0. 001 and 0. 003 respectively,the average interspecific genetic distance between A. hoantchy Franch. and A. dshimensis Gontsh. was 0. 010,and the distances between these two species and A. coluteocarpus Bioss. were 0. 015 and 0. 016 respectively. Additionally,the average interspecific genetic distance between A. hoantchy Franch. and A. dshimensis Gontsh. was indicated to be larger than their intraspecific genetic distance. The topological structure of the phylogenetic trees constructed with ML and BI methods was similar,in which three distinct clades were comprised of individuals of three studied species respectively. This study not only revealed the genetic relationship of the three related species,but also provided the molecular evidences to support that A. dshimensis Gontsh. is a separate species.

关 键 词：黄耆属 近缘种 边陲黄耆(Astragalus dshimensis Gontsh.) 分类地位 系统发生 

分 类 号：Q949[生物学—植物学]