|
|
|
| Research on Phylogeny in Different Geographical Populations of the Conogethes punctiferalis(Guenée) in China Estimated by Mitochondrial Cytochrome OxidaseⅡ Gene(COⅡ) Sequences |
| 1, 1, 1, 1, 1 |
|
|
|
|
Abstract Yellow peach moth, Conogethes punctiferalis(Guenée) (Lepidoptera: Crambidae), which is a polyphagous insect pests, has become more serious on corn in some corn planting areas in recent years. To investigate the genetic differentiation and phylogeny evolution within and among the different populations of the C. punctiferalis in China, we analyzed mitochondrial cytochrome oxidase Ⅱ (COⅡ) sequences of 24 geographical populations collected from different provinces and cities in China, including Guangxi, Guangdong, Sichuan, Hubei, Zhejiang, Shandong, Hebei, Henan, Beijing and Liaoning. In the total number of 622 C. punctiferalis individuals, 57 variable sites and 53 haplotypes were detected respectively (Genbank Accession numbers: JQ363873~JQ363922). In the nucleotide of C. punctiferalis partial COⅡ gene sequences, the average A+T content was 75.32%, which indicated obvious base A/T bias. In all 53 haplotypes, Hap2 was the most common haplotype, which included 67.36% of individuals tested, while 31 haplotypes were very rare in C. punctiferalis populations which were only appeared once in all collected samples. The average gene flow (Nm) among the 24 populations was 1.09, and the overall fixation index (Fst) was 0.585. It revealed that there was different level of genetic differentiation among the C. punctiferalis populations in China. Fst value of South region (Fst=0.24381) was higher than that of North and East regions (Fst=0.01197) and Southwest region (Fst=0.0133). The result was in accord with gene flow results (North and East regions Nm=41.58, Southwest region Nm=118.90, South region Nm=0.99) which indicated that the level of gene flow was very low with obvious differentiation among the different populations in South region and other regions. However the gene flow among the different populations of C. punctiferalis in North and East regions and Southwest regions were considerably frequent. Those variable sites accounted for 7.87% of all sites analysed. The Neighbor-Joining (NJ) phylogenetic tree and network relationship of the 53 haplotypes revealed that there was long genetic distance among haplotypes between South region populations of Guangdong, Guangxi and other populations, while no remarkable correspondence between haplotypes and geographical distances were found in other populations. Molecular variance (AMOVA) analysis indicated that a high proportion of the total genetic variance was attribute to variations within populations (89.99%); We analyzed the nucleotide mismatch distribution and did neutrality test using Tajima's D and Fu's Fs test method, the value of Taijima's D (-2.5776) was at significant level (P<0.01), and Fu's Fs was below zero. Besides, the mismatch was appeared uneven unimodal pattern. All these result suggested that for C. punctiferalis, there might have been population expansion in history, and the population expansion happened a long time ago (presumptively about 46 700 ~116 800 years ago).
|
|
Received: 12 March 2012
|
|
|
|
|
|
|
