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为了探讨DNA条形码技术在花卉害虫防治时用于蚜虫物种的快速、准确鉴定的可行性,本研究利用条形码通用引物扩增了危害广州市常见菊花品种的2种蚜虫,桃蚜Myzus persicae(Sulzer)和棉蚜Aphis gossypii Glover的DNA条形码。通过分析获取的2种43个样本的线粒体细胞色素C氧化酶亚基I(mitochondrial cytochrome c oxidase subunit I,COI)基因658 bp序列后发现,碱基平均含量为39.8%T,14.3%C,35.3%A,10.6%G,其中A+T含量为75.1%,C+G含量为24.9%,存在明显的A、T碱基偏好性,符合昆虫线粒体基因碱基组成的基本特征;有保守位点551个,可变位点62个,简约位点56个,单个突变位点6个。序列饱和性检验分析结果显示该序列转换与颠换未达到饱和,因此可以进行基于Kimura双参数模型的种内种间遗传距离分析。所有样品的种内平均差异为0.08%(0.00%~1.20%±0.18%),种间平均序列差异为9.69%(9.60%~10.30%±0.13%)。同时,邻接法(neighbor-joining,NJ)构建的系统发育树显示采自不同地区不同菊花品种上的桃蚜和棉蚜分别聚为一支。因此,本研究证明应用基于COI基因片段的DNA条形码进行花卉常见蚜虫类害虫的快速鉴定具有可行性。
In order to explore the feasibility of DNA barcoding technique for the rapid and accurate identification of aphid species in the control of flower pests, two kinds of aphids, Myzus persicae (Sulzer), which are harmful to common chrysanthemum varieties in Guangzhou, were amplified by barcode universal primers. And the DNA barcode of Aphis gossypii Glover. By analyzing 658 bp of mitochondrial cytochrome c oxidase subunit I (COI) gene of two kinds of 43 samples, we found that the average content of base was 39.8% T, 14.3% C and 35.3 % A and 10.6% G. The A + T content was 75.1% and the content of C + G was 24.9%. There was obvious A, T base preference, which was in line with the basic features of insect mitochondrial gene base composition. 551, 62 variable sites, 56 simple sites and 6 single mutation sites. The result of sequence saturation analysis showed that the sequence conversion and transversion were not saturated, so the intraspecific genetic distance analysis based on the Kimura two-parameter model could be carried out. The average intraspecific difference for all samples was 0.08% (0.00% -1.20% ± 0.18%), with an average of 9.69% (9.60% -10.30% ± 0.13%) difference between species. Meanwhile, the phylogenetic tree constructed by neighbor-joining (NJ) showed that the populations of Myzus persicae and Aphis gossypii were clustered together in different varieties of chrysanthemum in different regions. Therefore, this study proved that the application of DNA barcodes based on COI gene fragments is feasible for the rapid identification of common aphid pests in flowers.