基于三个分子标记的粉毛蚜亚科DNA条形码

【目的】粉毛蚜亚科昆虫是重要的林业害虫,但是由于蚜虫体型较小,形态特征趋于简化,可用于物种鉴定的有效特征非常有限,因此一般基于外部形态特征难以对蚜虫物种实现快速准确的鉴定。本研究获取该亚科2属10种的DNA条形码标准序列,解决部分物种的分类问题,同时比较了3种标记对粉毛蚜亚科(Pterocommatinae)物种快速鉴定的效率。【方法】基于蚜虫的线粒体细胞色素氧化酶C亚基I(cytochrome oxidase subunit I,COI)基因、细胞色素b(cytochrome b,Cytb)基因和蚜虫初级内共生菌Buchnera 6-磷酸葡萄糖酸脱氢酶(gluconate-6-phosphate dehydrogenase,gnd)基因,对2属10种共197号样品进行NJ分析、遗传距离的计算以及基于相似性的物种鉴定分析。【结果】与K-2P模型相比,基于p-distance模型计算得到的遗传距离更小,序列差异频次图上种内距离与种间距离的重叠区域也小于前者;COI序列的物种鉴定成功率最高。获取了粉毛蚜亚科近200条DNA条形码标准序列,并建立了基于3个标记的该亚科物种DNA条形码序列库。【结论】在粉毛蚜亚科DNA条形码研究中,pdistance模型要优于K-2P模型;COI序列具有最高的条形码分析效率;增毛卷粉毛蚜Plocamaphis assetacea可能为蜡卷粉毛蚜Plocamaphis flocculosa的同物异名。

DNA barcoding of Pterocommatinae (Hemiptera: Aphidoidea: Aphididae) based on three molecular markers

【Aim】 The aphid species in Pterocommatinae are important forestry pests. However, the aphids are in small size, their morphological characteristics tend to be simplified, and effective features for species identification are very limited, so the fast and accurate identification is hard based on external morphological characteristics. DNA barcode is an effective method for species identification. This study aims to compare the efficiency of rapid identification of Pterocommatinae based on three different molecular markers, to get the standard sequences of DNA barcode of this subfamily aphids and to solve the taxonomical problem of some species. 【Methods】 Based on COI, Cytb and Buchnera gnd genes, 197 samples of ten species in two genera were selected for the neighbor joining tree analysis, distance analysis and similarity-based DNA identification analysis under K-2P model and p-distance model. 【Results】 Compared with the K-2P model, p-distance model got the smaller genetic distance and the overlap region of intra- and interspecific divergences. COI sequences had the highest success rate of species identification. The nearly 200 standard sequences of DNA barcode for aphids of Pterocommatinae had been gotten, and the DNA barcode sequence library of the subfamily species had been built based on the three markers. 【Conclusion】 The p-distance model is superior to K-2P model, and COI sequences have the highest analysis efficiency. Plocamaphis assetacea may be a synonym of Plocamaphis flocculosa.