Abstract: Based on 16S rDNA sequences,the genetic variation and phylogenetic relationship of different bumblebees in the Sanjiangyuan region were studied systematically,which is of great significance to further study the adaptation,evolution and biodiversity conservation of bumblebees in the region. A total of 21 haplotypes of 17 species of bumblebees belonging to 9 subgenera were sequenced in the Sanjiangyuan region,with a total length of 496 bp. The base composition analysis showed that the transversion value was higher than the transition value,there were 159 variation sites (V),and there were large variation among haplotypes. Combined with the 16S rDNA sequences of 39 other bumblebees from 9 subgenera downloaded by Genbank,the genetic distances and phylogenetic analysis of 56 bumblebees belonging to 9 subgenera were performed. The results showed that:The genetic distances between 17 bumblebees in the Sanjiangyuan region ranged from 0.029 to 0.128;The average genetic distance within the subgenus ranged from 0.023 to 0.075,the genetic distance between subgenera ranged from 0.057 to 0.102,the genetic distances within subgenera were significantly smaller than that between subgenera;Phylogenetic trees were established by neighbor-joining method (NJ method) and maximum likelihood method (ML method),and the topological structure of the two trees were roughly the same,all 17 species of bumblebees in the Sanjiangyuan region were closely related to other species of the same subgenus.

Key words: Sanjiangyuan region, Bumblebees, 16S rDNA, Sequence variation, Genetic distance

摘要： 本研究基于16S rDNA序列对三江源地区不同熊蜂的遗传变异和系统发育关系进行了系统分析，对于深入研究三江源地区熊蜂的适应与进化及生物多样性保护具有重要意义。研究共测序获得三江源地区9个亚属17种熊蜂的21个单倍型，序列全长496 bp。碱基组成分析表明：颠换值高于转换值，变异位点(V)共159个，单倍型间存在较大的变异。结合Genbank下载的该9亚属其他39种熊蜂的16S rDNA序列，对该9个亚属的56种熊蜂进行了遗传距离和系统发育分析，结果表明：三江源地区17种熊蜂间遗传距离为0.029~0.128；亚属内平均遗传距离为0.023~0.075，亚属间遗传距离为0.057~0.102，亚属内遗传距离明显小于亚属间；通过邻接法(NJ法)和最大似然法(ML法)建立系统发育树，两树拓扑结构大致相同，三江源地区的17种熊蜂均与同亚属其他物种的亲缘关系最近。

关键词: 三江源地区, 熊蜂, 16S rDNA, 序列变异, 遗传距离