微卫星标记分析大鳞鲃养殖群体的遗传结构及生长性状

Analysis of genetic structure and growth traits in Barbus capito using microsatellite markers

大鳞鲃作为水产引进种,受建群数量较小的影响其遗传资源相对有限,因此在育种实践中有效地保护和利用现有的基因资源显得尤为重要。实验用24个微卫星标记分析了大鳞鲃养殖群体的遗传结构,在随机采样的96个个体中共检测到74个等位基因,各标记等位基因数为2～5个,片段大小为109～367 bp,有效等位基因数(Ne)为1.144 5～4.626 4,观测杂合度(Ho)为0.135 4～1.000 0,期望杂合度(He)为0.126 9～0.788 1,标记的多态信息含量(PIC)为0.118 3～0.749 0,平均为0.428 1。统计结果显示,大鳞鲃养殖群体处于中度多态水平;经χ2检验估计Hardy-Weinberg平衡,结果表明,大鳞鲃养殖群体处于平衡状态,但有8个微卫星标记显著偏离了平衡。利用SPSS 19.0的GLM模型分析24个微卫星标记与体质量、体长、体高和体厚的相关性,结果表明,B1、B20、B45、B51、B59、BC38与4项生长性状均具有显著相关性,B26与体质量、体高和体厚具有显著相关性,BC3与体质量和体长具有显著相关性,进而使用Duncan氏多重比较找到了每个微卫星标记具有生长性状优势的基因型。

Barbus capito is an endemic species in the Aral Sea of Uzbekistan. It is well-known for its salt tolerance and fast growth, and is a valuable food source in the region. The species was introduced to China in 2003 and F1 was obtained using artificial propagation in 2010. As an introduced species,B, capito has the relatively limited genetic resources due to the small founder population size. It is very important to effectively protect and utilize the existing gene resources in breeding practice. In this study,24 microsatellite markers were selected to analyze the genetic structure in cultured F1 population including 96 individuals. A total of 74 alleles were detected and the length of fragments ranged from 109 to 367 bp. The number of alleles per locus was from 2 to 5, and the mean was 3. 0833. The effective number of alleles （ Ne ） ranged from 1. 144 5 to 4. 626 4 with an average of 2. 265 6. The observed heterozygosity （Ho ） and the expected heterzygosity （ He ） varied from 0. 135 4 to 1.000 0（mean =0.538 4）and from 0. 126 9 to 0.788 1（mean =0.487 2）, respectively. The value of polymorphic information content（PIC） was between 0.118 3 and 0. 749 0 with an average of 0. 428 1, and this result indicated that the level of genetic diversity was moderate （0.25 ≤PIC 〈 0.50）. The population accorded with Hardy-Weinberg equilibrium checking by Х^2 test except 8 markers including B 1, B20, B32, B37, B45, B51, B68, and BC43. In addition, the correlation was analyzed between 24 microsatellite markers and growth traits using the GLM procedure of SPSS 19.0. As a result, there were 8 markers that had a significant（ P 〈 0.05 ）impact on growth traits. Six markers including B1, B20, B45, B51, B59, and BC38 had a significant（ P 〈 0.05 ）impact on body weight, length,height,and thickness. B26 had a significant（ P 〈 0.05 ） impact on body weight, height, and thickness. BC3 had a significant（ P 〈 0.05 ） impact on body weight and length. Superior genotypes were obtained using Duncan＇ s multiple comparison.