基于线粒体 D-loop 区序列的 4 个黄尾鲴 养殖群体遗传多样性分析.

【Objective】Xenocypris davidi is a freshwater economic fish, which feeds on humus, organic debris, plankton, and benthic animals, is one of the main fish for stock enhancement in Zhejiang Province. The research is aims to understand the impact of artificial breeding on the genetic diversity of X. davidi, and to provide basic data for the design and implementation of stock enhancement strategies for X. davidi in natural waters.【Method】D-loop region of mitochondrial DNA (mtDNA) of four cultured X. davidi populations from Changxing, Balidian, Shuangpu in Zhejiang Provice and Liling in Hunan Province were amplified and sequenced. The genetic diversity of the four populations was studied by sequence analysis.【Result】 The mitochondrial D-loop sequence length of the X. davidi was 1 038-1 093 bp, and the base A+T content (65.3%) was significantly higher than the C+G content (34.7%), the average transitions and transversions ratio (TS/TV) was 4.6. A total of 101 mutation sites including 97 reduced information sites were detected in 128 D-loop sequences of X. davidi, and defining 19 haplotypes. Among them, the haplotype numbers of Changxing, Shuangpu, Balidian, and Liling populations were 5, 12, 4, and 2, respectively. The haplotype diversity (h) ranged from 0.226 to 0.915, and the nucleotide diversity (π) ranged from 0.00640 to 0.01433. The genetic distance between different breeding populations was 0.03782-0.88756, the genetic differentiation coefficient among populations was 0.78903 (P<0.01), among which the degree of genetic difference between Changxing and Balidian populations was the lowest, and that of Shuangpu and Liling populations was the highest, and the genetic variation mainly occurred among populations.【Conclusion】There are certain differences in genetic diversity among the four cultured X. davidi populations. The results of the genetic variation and population structure of X. davidi will provide reference data for the comparative study on the genetic diversity of the X. davidi, and contribute to the resource protection. [ABSTRACT FROM AUTHOR]