Phylogeny And Molecular Detcetion Of Coptotermes (Isoptera:Rhinotermitidae)

Coptotermes Holmgren (Isoptera:Rhinotermitidae) is the most economically important structural and agricultural termites. Coptotermes spp. (non-Chinese) were listed as the entery quarantine pest in China. It is difficult to identify termites based on morphological characteristics, espcially Coptotermes. In this dissertation, sequences and phylogentic analysis of Coptotermes species were studied, and molecular detection methods were estabilished based on internal transcribed spacer gene (ITS).Information of quarantine species of Coptotermes intercepted since 1990 by CIQ were collected and morphological characteristics of some important species were descripted. Results showed that the number of quarantine Coptotermes reached 24 and the most interception rate was C curvignathus. Soldiers of some species in genus Coptotermes are difficult to distingish from the morphological characteristics such as numbers of setea and the coloration. Measurements of interspecies from different populations are not stable.Sequence divergence and phylogeny relationships were investigated using two genes, COII and ITS of 17 and 18 populations, respectively, which from 7 species of genus Coptotermes. The nucleotide compositions of COII gene is diffierent from ITS gene, that the content proportion of COII sequence of AT (61.2%) was higher than CG while the CG (62.2%) was higher than AT in ITS sequence, and more transversions were happened than transitions in this two sequences. The identity percent of COII and ITS of interspecies were 88.8% ～95.9% and 95.1% ～98.5% while the genetic distance were 0.041～0.113 and 0.015～0.038; Especially between C. curvignathus and C. sepangensis, based on the COII gene, identity percent was 98.8%～99.8% while genetic distance was 0.002～0.006, phylogentic analysis showed a very close relationship bewteen this two species simultaneously. Meanwhile supported by the molecular information from ITS, it is suggested that C. curvignathus and C. sepangensis seems to be synonymous.Regular polymerase chain reaction (PCR) and Real-time fluorescent quantitative polymerase chain reaction (FQ-PCR) were developed through designed specific primers and TaqMan probe which according to the conserved sequences of internal transcribed spacer (ITS) of the quarantine pest C. curvignathus. Both of the methods showed high specific strength and strong stability, and the limited detection could be reached lng/μl by regular PCR and 0.1pg/μl by FQ-PCR. This detection system could be useful for distinguishing C. curvignathus and other identical species.