线粒体COI和CYTB基因在虫草属物种寄主昆虫鉴定中的适用性分析

目的：利用DNA条形码技术对冬虫夏草、凉山虫草、亚香棒虫草、戴氏虫草等物种的寄主昆虫分别通过COI序列和Cytb序列进行条形码分析，探索虫草属物种寄主昆虫鉴定序列的适用性。方法：通过DNA提取、PCR、电泳检测和序列测定，分别获得26份虫草寄主虫体的COI序列和Cytb序列，再用拼接和分析软件进行序列的比对和聚类分析。结果：COI序列和Cytb序列都能很好地区分鉴定虫草类各物种，但COI序列的扩增成功率大于Cytb基因，同时在COI基因片段中共检测到129个多态位点，变异率为19.51%；在Cytb基因片段中共检测到113个多态位点，变异率为26.10%。COI序列的简约信息点多于Cytb序列，且基因变异率低于后者。结论：本研究建议COI序列更适用于虫草寄主昆虫的DNA条形码研究。

Feasibility Analysis on Mitochondrial COI and Cytb Gene Used for Identification of Parasitic Insect of Cordyceps

This study was aimed to explore the feasibility of DNA barcode sequence of parasitic insect of Cordyceps. The COI and Cytb sequences were combined in the analysis of the species of Ophiocordyceps sinensis, Metacordyceps liangshanensis, Cordyceps hawkesii and Cordyceps taii. After DNA extraction, PCR, electrophoresis detection and sequence analysis of 26 species of Cordyceps samples, the COI and Cytb sequences were received. The assembly and analysis software were used in the sequence comparison and cluster analysis. The results showed that both COI sequences and Cytb sequence can better identify the various species of Cordyceps. However, the amplification success rate of COI sequences was greater than Cytb gene. And there were 129 polymorphic loci detected in the COI gene sequences. The mutation rate was 19.51%. There were 113 polymorphic loci detected in the Cytb gene sequences. The mutation rate was 26.10%. The simple information points of COI sequences were more than that of Cytb sequence. And its mutation rate was less than the latter one. It was concluded that COI sequence was more suitable for the DNA barcoding research of parasitic insect of Cordyceps.