【摘要】 利用DNA条形码技术对收集到的8种草地螟寄生性天敌昆虫线粒体DNA细胞色素C氧化酶亚基Ⅰ(mtDNA COⅠ)的部分序列进行测定,通过比对分析,以邻接法(NJ)和最大简约法(MP)构建天敌昆虫系统发育树,以Kimura双参数模型计算天敌昆虫种内及种间的遗传距离。结果发现:与Genbank中寄生蝇及寄生蜂序列进行对比、剪切,共得到584bp的寄生蝇条形码基因序列49条、625bp的寄生蜂条形码基因序列45条。其中,49条寄生蝇的平均碱基含量中AT含量为71.1%,大于GC含量;45条寄生蜂的平均碱基含量中AT含量为74.0%,大于GC含量;均表现出AT偏向性。4种寄生蝇种内平均遗传距离为0.0015,种间平均遗传距离为0.1137;4种寄生蜂种内平均遗传距离为0.0015,种间平均遗传距离为0.3010,两类天敌昆虫的种间遗传距离均远大于种内遗传距离;聚类分析显示每一种天敌对应一个分支。说明基于COⅠ基因的条形码技术可以用于草地螟寄生性天敌昆虫的鉴别。更多还原

【Abstract】 Loxostege sticticalis Linnaeus is a kind of worldwide pests of husbandry and there are many natural enemies in nature. The purpose of this study is to clarify the identify of the parasitic natural enemy insects of L. sticticalis. We used DNA barcoding technology to determine the partial sequences of mitochondrial cytochrome coxidase subunit Ⅰ gene(CO Ⅰ) of 8 species of parasitic natural enemies of L. sticticalis. Based on the comparison analysis, we use neighbor-joining(NJ) and maximum parsimony(MP) to construct phylogenetic tree and Kimura’s two-parameter model to calculate the intraspecific and interspecific genetic distance of enemy insects. The results indicated that by comparing and shearing the sequences of parasitic flies and parasitic wasps in Genbank, a total of 94 bar code gene sequences of parasitic flies of 584 bp and 625 bp of parasitic wasps were obtained; The average AT content of 49 parasitic flies was 71.1%, higher than that of GC content(28.9%); The average AT content of 45 parasitic wasps was 74.0%, which was higher than GC content(26%), all of them showed AT bias. The average intraspecific genetic distance of four tachinids was 0.0015, average interspecific genetic distance was 0.1137, the Average intra-specific genetic distance of four parasitoids was 0.0015, average inter-specific genetic distance was 0.3010, the genetic distance between species is much larger than those within species; Cluster analysis showed that there was a branch for each natural enemy. The barcoding technology based on CO Ⅰ gene can be used for the identification of parasitic natural enemies of L. sticticalis.更多还原