| Thysanoptera insects are generally called thrips, minority types are the farming and forestry harmful pests. Frankliniella intonsa (Trybom) does a lot of harm to crops, vegetables and flowers. Therefore, further studying its differentiation mechanism and the condition, which has important theory significance in riching the biological evolution theory and the species correct division, has practical significance in integrated control.In this paper, molecular marker used mitochondrial cytochrome oxidaseâ… gene fragment for Frankliniella intonsa in 14 different geography distribution, include Beijing, shanghai and other 12 kinds of thrips with the following methord. First extracted genome DNA, then a pair conservation primer used to amplify COâ… gene fragment of mitochondrial DNA, later mensurated sequence.The experimental result showed that : this mark fragment was conservative of intraspecies, the individuals of Frankliniella intonsa have 9 haplotypes, and the intraspecies genetic distance is 0~0.019; The Frankliniella intonsa has 8 sequence variation between the Inner Mongolia and the Shaanxi, the genetic distance is biggest, 0.019; The sequences of Frankliniella intonsa from Beijing, Jilin, Liaoning, Hebei and Shanxi do not have the difference, and between Shanghai and Jiangsu, the genetic distance is 0; Thrips Hawaiiensis has 13 sequence variations between 2 haplotypes, the average intraspecies genetic distance is 0.031; The variation of this fragmenis is comparatively high in the inter-species, there are 85 sequence variations averagely in pairs, the inter-species genetic distance scope is 0.154~0.311, the average inter-species genetic distance is 0.234. The inter-species genetic distance scope of Frankliniella is 0.184~0.237, the average inter-species genetic distance is 0.205. The inter-species genetic distance scope of Thrips is 0.154~0.268, the average inter-species genetic distance is 0.208. The inter-species genetic distance scope between Anaphothrips obsurus and other thrips is 0.240~0.311, which is the biggest, the average inter-species genetic distance is 0.268. The inter-species genetic distance scope between Scirtothrips dorsalis and other thrips is 0.207~0.262, the average inter-species genetic distance is 0.237. The inter-species genetic distance scope between Megalurothrips distalis and other thrips is 0.205~0.272, the average inter-species genetic distance is 0.237. This experiment used 3 different methods (NJ, MP, UPGMA), the NJ is possible simplist to construct the genealogical tree quickly, simultaneously, it is quite suitable to analyse large data, the examination of bootstrap values are also time-saving. Furthermore, thrips individuals are successfully clustered by NJ tree. The bootstrap values of the original divergence among intra-species haplotypes amount to 100%. Blood relationship of each species approximately tallies with the traditional classification result. It showed that the NJ tree based on the model MEGA4.0 may satisfy the species appraisal well.The results showed that there was no obvious genetic divergence between Frankliniella intonsa of different geography population. Molecular identification based on PCR and direct sequencing is desirable to identify thrips species. |
