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【背景】米尔顿姬小蜂是一种入侵我国台湾地区的植食性小蜂,能够严重影响水果的产量和食用价值。目前在我国大陆没有分布,由于其个体微小,与近似种区别较小,通过传统的形态学分类方法难以鉴定,因此有必要研究其基因片段序列,探讨分子鉴定方法。【方法】利用PCR方法扩增并测定了米尔顿姬小蜂线粒体16SrRNA和COⅠ基因的部分序列,并对各序列的碱基组成进行了分析。然后根据COⅠ基因部分序列,利用DNAMAN的Maximum Likelihood方法构建了米尔顿姬小蜂与膜翅目其他科的系统发育树。【结果】16SrRNA基因的PCR扩增产物为426bp,COⅠ基因的PCR扩增产物为488bp。通过测序获得米尔顿姬小蜂16SrRNA和COⅠ基因部分序列,序列分析表明,16SrRNA和COⅠ基因的A+T含量均较高,存在较强的A+T偏向性。系统发育树显示,米尔顿姬小蜂与蚜小蜂科的Encarsia berlesei亲缘关系最近,与姬小蜂科的Chrysocharis nautius、C.eurynota亲缘关系较远。【结论与意义】本研究为米尔顿姬小蜂的分子鉴定提供了依据。
【Background】 Miltonia wasps is a kind of insectivorous wasps that invade the Taiwan area of our country, which can seriously affect the yield and edible value of fruits. At present, there is no distribution in mainland China. Due to its small size and little difference from the approximate species, it is difficult to identify by traditional morphological classification methods. Therefore, it is necessary to study the sequence of gene fragments and to explore molecular identification methods. 【Method】 The partial sequences of mitochondrial 16S rRNA and COⅠ gene were amplified by PCR and the nucleotide composition of each sequence was analyzed. Then according to the partial sequence of COⅠ gene, the phylogenetic tree of Helicoverpa armigera and other families of Hymenoptera was constructed by using DNAMAN Maximum Likelihood method. 【Result】 The result of PCR amplification of 16S rRNA gene was 426bp and that of COⅠ gene was 488bp. The sequences of 16SrRNA and COⅠ gene were obtained by sequencing. The sequence analysis showed that A + T content of 16SrRNA and COⅠ gene were high, and there was strong A + T bias. Phylogenetic tree shows that the closest relationship between Encarno-berlesei and Helicoverpa spp. Is relative to Chrysocharis nautius and C. eurynota. 【Conclusion and Significance】 This study provides the basis for the molecular identification of the Myrtles.