关键词: 银杏大蚕蛾, 地理种群, COI基因, 遗传分化, 系统发育分析, 中国

Abstract: Caligula japonica, an endemic species in eastern Asia, is not only an important forestry pest to be controlled, but also a precious wild silkmoth resource to be domesticated for silk production. In order to clarify the genetic relationship of the geographic populations of C. japonica, we determined the 574 bp segment of the mitochondrial cytochrome oxidase subunit I (COI) gene sequences from 12 geographic populations in China (GenBank accession no. FJ358506-FJ358517), and then analyzed the sequence variability of the COI gene and genetic differentiation among them. The identity of COI pairwise sequences was 99%-100% among the geographic populations of C. japonica, which indicated a low genetic diversity. In total, six haplotypes were identified within the sequences, with nine sites showing polymorphism and three haplotypes shared. Molecular phylogeny analysis showed that populations sampled were well divided into “Northern” and “Southern” groups. AMOVA analysis showed that there were apparent genetic differentiation between the “Northern” group and the “Southern” group (FST=0.478, P<0.001). It is inferred that the genetic differentiation between the “Northern” group and the “Southern” group should be related to ecology adaptation of C. japonica. The results of this study provide a basic molecular biology clue to the studies on population genetics and ecology of C. japonica.

Key words: Caligula japonica, geographic populations, COI gene, genetic differentiation, phylogenetic analysis, China