Peach Bore Fruit The Moth Carposina Sasakii Complex Molecular Evolution

The peach fruit borer, Carposina sasakii Matsumura complex, is an important fruit pest in China and East Asia. It can cause severe damage on apple, common jujube, hawthorn, peach, apricot, and plum, etc.In this study, seven different populations infesting various fruit trees including apple, peach, apricot, common jujube, hawthorn, wild jujube, and dogwood, are used to study the speciation mechanism of the C. sasakii complex by means of RAPD (random amplified polymorphic DNA) and DNA sequencing.The genome DNAs from the different populations are extracted separately. First, three primers are used to detect the genetic similarity withingroup and the genetic distance intergroup. Eleven primers and one sample are used to detect the genetic distance intergroup. The cluster analysis is done based on the genetic distance. Some kinds of genetic distance are calculated i.e. the Nei's distance and Euclidean Distance, etc. Nearest neighbor method. Unweighted pair-group method using arithmetic averages, (UPGMA), and Neighbor-joining method(NJ) are used to draw the dendrograms. The results show that there are great genetic polymorphism. And the populations on apple, wild jujube, hawthorn, common jujube, and peach can be categorized as one subgroup, the population on the apricot as one subgroup. The genetic similarity in different populations varies, those on common jujube and apple are lower, but that on hawthorn higher, suggesting that the gene flow is from hawthorn and wild jujube or common jujube and peach to apple population.A pair conservation primer is used to amplify the COII gene fragment of mitochondrial DNA (mtDNA). This fragment is 530bp long. After sequencing the amplified fragment, we get a 497bp long sequence data. The DNA sequence analysis software DNAstar is used to analysis the COII gene, the gene is found different nucleotide substitution in different populations. The dogwood population has 38 base mutations, apricot population has 9 base mutations, the mutation rates are corresponding to 7.6% and 1.8%. The nucleotide substitution is 34-41 bases between species, and is 2-12 base within species. Between species exhibited 7.6%-9.2% divergence, the apricot population exhibited 1.2%-2.9% divergence from other population.RAPD analysis and COII DNA sequences show that the apricot population probably has evoluted into a new species. The divergence reason of the C sasakii complex is the adaptation to their host phenological phase. RAPD method and COII gene sequencing are accurate and quick for subspecies analysis on C. sasakii complex.