关键词: 红螯螯虾, 遗传多样性, 遗传结构

Abstract:

Cherax quadricarinatus is native to Australia with good breeding prospects. In the present study, the genetic diversity and structure of five cultured populations of Cherax quadricarinatus were evaluated based on mitochondrial COⅠ sequences, to provide basic data for scientific introduction, variety selection, and germplasm resource protection. The results showed that the complete sequence of the mitochondrial COⅠ region was 1 534 bp, of which 24 were variation sites, accounting for 1.6% of the analysis sites. In the 24 variation sites, 22 were parsimony-informative sites, and the average transversion ratio was 6.14. The content of (A+T) (58.7%) was higher than that of (G+C) (41.3%). A total of 35 haplotypes were defined in 143 individuals. Zhejiang, Hainan, and Taiwan cultured populations had some shared haplotypes (COⅠ-01, COⅠ-02, and COⅠ-03), and these three haplotypes were dominant also. The haplotype diversity of Jiangsu cultured population (0.739) was the lowest, while the highest was found in Anhui cultured population (0.881). The haplotype diversity index and nucleotide diversity index of whole samples were 0.896 and 0.004 65, respectively. The genetic distance between different cultured populations varied from 0.002 63 to 0.006 81, and the genetic distance between Zhejiang and Hainan cultured populations was the closest, while the genetic distance between Hainan and Anhui cultured populations was the furthest. The genetic differentiation coefficient within populations was 0.342 1 (P<0.01), indicating genetic differentiation within populations. The genetic diversity of the five cultured populations of C. quadricarinatus was different, indicating that there was some gene exchange among populations. These results provided molecular biological basis for the rational development and utilization of the germplasm resources of C. quadricarinatus.

Key words: Cherax quadricarinatus, genetic diversity, genetic structure