基于28S rRNA D2序列的内茧蜂亚科的分子系统发育

摘要

首次利用同源28S rRNA D2基因序列对内茧蜂亚科Rogadinae(昆虫纲Insecta:膜翅目Hymenoptera:茧蜂科Braconidae)进行了分子系统学研究.本研究从95%～100%乙醇浸渍保存的标本中提取基因组DNA并扩增了10种内群种类和5种外群种类的28S rDNA D2片段并测序(GenBank序列号AY167645-AY167659),利用BLAST搜索相关的同源序列,采用了GenBank中13个种类的28S rRNA D2同源序列,然后据此进行分子分析.利用3个外群(共8个种类)和3种建树方法(距离邻近法distance-based neighbor-joining,NJ;最大俭约法maximum parsimony,MP;和最大似然法maximumlikelihood,ML)分析了内茧蜂亚科内的分子系统发育关系.结果表明,由分子数据产生的不同的分子系统树均显示内茧蜂亚科是一个单系群.内茧蜂亚科内依据形态和生物学特征的分群(族和亚族)及其系统发育关系得到部分支持.NJ、MP和ML分析结果均表明内茧蜂族Rogadini不是一个单系,而是一个并系,其余3族则得到不同程度的支持.内茧蜂族可分成2个分支:"脊茧蜂属Aleiodes+弓脉茧蜂属Arcaleiodes"和"沟内茧蜂属Canalirogas+锥齿茧蜂属Conspinaria+刺茧蜂属Spinaria+内茧蜂属Rogas",二者不是姐妹群.脊茧蜂属Aleiodes和弓脉茧蜂属Arcaleiodes始终是姐妹群.脊茧蜂属Aleiodes是一个单系,并可分成2个姐妹分支,这与依据形态和生物学特征的亚属分群相一致.弓脉茧蜂属Arcaleiodes Chen et He,1991是一个独立的属.分支"沟内茧蜂属Canalirogas+锥齿茧蜂属Conspinaria+刺茧蜂属Spinaria+内茧蜂属Rogas"的单系性仅得到部分分子数据的支持;因形态特异(腹部成甲壳状)而列为亚族级的刺茧蜂属Spinaria,分子分析没有证实这一点.横纹茧蜂族Clinocentrini是个单系,并在内茧蜂亚科的系统发育中处于基部(原始)的位置.我们研究结果还表明,阔跗茧蜂属Yelicones和潜蛾茧蜂属Stiropius相对应的阔跗茧蜂族Yeliconini和潜蛾茧蜂族Stiropiini为2个独立的分支,与形态和生物学的结果一致,但它们在内茧蜂亚科的系统发育的位置不明,有待今后进一步研究.%The D2 variable region of 28S ribosomal RNA was sequenced from ethanol preserved specimens or obtained from the literature to pro-vide the first molecular phylogenetic reconstruction of this subfamily. Evolutionary relationships were investigated by comparing the results usingthree different analysis methods (distance-based neighbor-joining, NJ; maximum parsimony, MP; and maximum likelihood, ML) and three differ-ent outgroups. The monophyly of the Rogadinae s. s. is well supported by all trees generated from molecular data. The morphologically definedtribes and the relationships within the subfamily are partially resolved. We found no evidence for a monophyletic Rogadini lineage, neither for themorphological subtribe division within the tribe, but we did find some evidence for three other tribes. Among the genera of Rogadini our resultsshow strong support for the paraphyly of this group. It can be divided into two clades, one consisting of Aleiodes + Arcaleiodes, the other ofCanalirogas + Conspinaria + Spinaria + Rogas. The clade Aleiodes + Arcaleiodes was constantly resolved using different outgroups with allAleiodes species forming a monophyletic group. Two distinct clades are found within Aleiodes, strongly corresponding to the morphologically de-fined subgeneric divisions of the genus. For the clade Canalirogas + Conspinaria + Spinaria + Rogas, we found only limited support for this cladeto be a monophyletic group. We did not find any support for the genus Spinaria to receive subtribe rank. The tribe Clinocentrini is well supportedin our analyses, and probably occupy a basal position in the phylogeny of the subfamily. We also found two well-supported clades containing thegenera Yelicones and Stiropius, corresponding to the tribes Yeliconini and Stiropiini, respectively, which were well defined by morphological data,but the placement of these two clades within the phylogeny of the subfamily is poorly resolved in this study.