关键词: 油松毛虫, CO Ⅰ 基因, 遗传分化, 林分类型

Abstract:

In order to clarify the effect of different stand types on the genetic structure of Dendrolinus tabulaeformis, we determined a 554 bp segment of the mitochondrial cytochrome oxidase subunit (CO Ⅰ) gene sequence of D. tabulaeformis populations from of 4 types of stands, and then analyzed the sequence variability and genetic differentiation. The results showed that in the gene sequence of 544 bp, the average contents of A, T, C and G were 30.6%, 39.4%, 15.3% and 14.7%, respectively, and the contents of A+T accounted for 70% of the total bases and were obviously higher than that of C+G, with an obvious A/T bias. In this sequence fragment, 64 nucleotide sites showed variation and the variability was 11.7%. Genetic distance of the nucleotide sequences was 0.002-0.046, indicating a low genetic variation. A dendrogram was constructed by using NJ and MP method, and the results showed that the genetic differentiations were correlated with the type of stands. Furthermore, the Fst coefficients of gene differentiation were between -0.128 to 0.117, and the number of migrant per generation was all greater than 1, manifesting that there were to some degrees genetic differentiation and gene exchange between D. tabulaeformis populations from different types of stands.

Key words: Dendrolimus tabulaeformis, CO Ⅰ gene, genetic differentiation, stand type