| The melon fly is an important invasive pest which is widely distributed in tropical and subtropical regions, including Hainan, Guangdong, Guangxi, Yunnan, Sichuan and other southern provinces in China. The host of melon fly is widely distributed in China, so it is harmful to our crops. In order to investigate the genetic variation, differentiation pattern,invasion, pervasion in different geographical populations and lmorphological mechanism of male and female adults. 120 samples of melon fly from 6 major provinces and 19 regions in China were researched by the CO I gene determine and polymorphic microsatellite loci as molecular markers to analyze the genetic relationships of populations and to establish phylogenetic trees. At the same time, the reference group had the transcriptome library of melon fruit fly, and the olfactory and internal reference genes of melon fly were screened by PCR and realtime fluorescence quantitative PCR. The main conclusions are as follows:The proportion of ATCG in the sequence was A % = 29.38 %; C % = 18.91 %; G % =13.60 %; T % = 38.11 %; A+T>G+C. There were 16 variable sites in the 640bp DNA sequences, including 7 parsimony-informative sites and 9 singleton sites. The Fst value is 0.10788, the Nm value is 2.07. The genetic distance is 0-0.0018. Neutral test Tajima's is D:-2.29747, which is extremely significant negative(P<0.01). The results showed that the genetic differentiation of pervasion was still at the initial stage, and there was some genetic communication and genetic differentiation among 19 regions. The Fst value of the population is 0.10788, indicating that the degree of differentiation is moderate. The 15 haplotypes were finding through CO I gene. Including 7 haplotypes and 8 haplotypes were unique to each population. Yunnan and Guangxi Province have more unique haplotype.Indicating that there is a certain degree of genetic differentiation in these areas.The results of POPGENE3.2 and Arlequin3.52 showed that the percentages of polymorphic loci was 96.49%, the mean value of Shannon's diversity index was 0.8799,and the genetic differentiation coefficient among populations was Fst=0.1309. The AMOVA software show that FST was not significantly different at each locus. The genetic variation of microsatellite was 86.91 %, the genetic variation of 13.09 % existed among the populations. MEGA UMPGA cluster analysis shows that the invasion of melon fly where were from Southeast Asia to Yunnan Province. The observed heterozygosity of the 19 geographical populations was from 0.3358 to 0.6667, the population of Nanchang is lowest,Yunnan Mengla and Guangxi Liuzhou were highest. The heterozygosity was from 0.3736 to 0.6287, which the population of Yunnan Nujiang lowest, and the population of Hainan Haikou was highest. The heterozygosity of each population was greater than the expected heterozygosity, indicating that the majority of the population was heterozygote. The genetic diversity of Leizhou population in Guangdong was highest, and the genetic diversity of Nujiang population in Yunnan was lowest.The results showed that: Yunnan Province has the highest genetic diversity of melon flies, followed by Guangdong Province, and the genetic differentiation was lowest in Hainan province. According to the different degree of genetic differentiation, the control strategies should be different. Yunnan, Guangxi and other regions of the melon fly has a certain degree of genetic differentiation,based on the actual situation,and combined with a variety of prevention and control methods to control the economic loss below the threshold.Hainan, Sichuan, Guangdong, Jiangxi and other regions with low degree of genetic differentiation, thus a unified and effective prevention methods can used.In order to study the difference of sex pheromone-binding protein gene between male and female sexes, RNA extraction and reverse transcription of different fruit trees were carried out for different treatments (high temperature 31 ? room temperature 25 ?, low temperature 19 ?), design of 12 pairs of primers for fluorescence quantitative, screening out the most stable internal reference gene is 5-1Q. Five sex pheromone binding proteins were identified by screening the library of melon fly and NCBI. The development of new behavioral interferants with insect odor binding protein as a molecular target and molecular biology technology provides a theoretical basis for the development of new insect behavior regulators and pest control. |
PDF Full Text Request