德国小蠊及其近缘种的形态和分子鉴定

Morphological and molecular identification of Blattella germanica and its closely related species

目的建立一种可以准确鉴定德国小蠊及其近缘种的形态学和分子鉴定方法。方法比较德国小蠊、拟德国小蠊、双纹小蠊、毛背小蠊和单尾小蠊等小蠊属近缘种的外部及雄性尾器的形态特征。获得种类分子鉴定普遍采用的标准DNA条形码片段——细胞色素C氧化酶亚基Ⅰ,分析其序列、种内和种间序列差异度,构建Neighbor-Joining树。结果德国小蠊及其近缘种在外部形态上差异较小,部分外部特征在相同种不同个体间不稳定,但其雄性尾器特征差异明显且稳定;种内不同个体间的DNA条形码序列差异<2%,种间DNA条形码序列差异均>2%。结论雄性尾器是德国小蠊及其近缘种形态鉴定的金标准,DNA条形码可作为种类分子鉴定的工具,为形态学鉴定的有效补充。

Objective To establish morphological and molecular methods for identification of Blattella germanica and its closely related species. Methods External morphology and male genitalia of B. germanica, B. lituricollis, B. bisignata, B. sauteri, and B. singularis were studied in details, the intra-species and inter-species differences of the commonly adopted molecular fragment for species identification-DNA barcodes（cytochrome C oxidase subunitⅠ）were analyzed, neighbor-Joining tree based on these fragments were constructed as well. Results Although the difference of external morphology among B. germanica and its closely related species were not remarkable, and some of the external morphology characteristics between different individuals within the same species were not stable,the differences of the male genitalia among different species were stable and obvious. Intra-species DNA barcode differences of the studied species were less than 2%, and inter-species DNA barcodes differences were more than 2% which is the limitation of DNA barcodes species identification. Conclusion Male genitalia are the golden standard for species morphological identification of B. germanica and its closely related species, DNA barcoding is a good tool for species molecular identification and is supplemental tomorphological identification.