AFLP analysis of genetic diversity of shrimp Litopenaeus vannamei | 基于AFLP技术的凡纳滨对虾遗传多样性研究

Chinese. 对凡纳滨对虾（Litopenaeus vannamei）人工繁育养殖群体进行遗传多样性评价，获得家系间和家系内的差异，为凡纳滨对虾遗传育种工作提供技术支持。采用AFLP分子标记技术，对抽查的凡纳滨对虾35个家系共计350个样品进行遗传多样性分析，统计多态性条带，应用Popgene Version 1.31、Arlequin Version 3.1、Mega 3.1软件，计算各家系的Shannon指数、遗传分化系数Fst及基因流Nm等遗传参数，采用UPGMA法，根据Nei’s遗传距离绘制家系间的聚类分析图。筛选的10对选择性引物共扩增出312个可用于分析的位点，其中多态性位点162个，占总标记数的51.92%；凡纳滨对虾各个家系的多态位点百分率和Shannon指数分别为12.50%~32.69%和0.068 3~0.181 7。所有家系中，有36.38%的变异存在于家系间，有63.62%的变异为家系内的遗传变异，遗传分化系数Fst为0.363 8，基因流Nm为0.937 2。凡纳滨对虾群体遗传多样性较为丰富，具备一定的选择潜力，在传代过程中已经形成了各自相对独立的遗传体系，可以根据亲缘关系，选择利用其中的个体作为育种材料。

English. The study was done to evaluate the genetic diversity of cultured Litopenaeus vannamei in order to provide a technical basis for inheritance breeding work. Amplified fragment length polymorphism (AFLP) technique has been used to analyze the genetic variation among a total of 350 indiciduals representing 35 families of L. vannamei. The number of polymorphic loci was counted. Popgene Version 1.31, Arlequin Version 3.1 and Mega 3.1 were taken to calculate the genetic diversity index of the families of Shannon’s genetic diversity index and the genetic differentiation index of Fst. Cluster analysis was performed between 350 individuals of 35 families using UPGMA method based the Nei’s distance. Ten pairs of selective primers produced 162 polymorphic markers out of 312 bands amplified. The percentage of polymorphic loci was 51.92%. The percentage of polymorphic loci and Shannon index among families was between 12.50%-32.69% and 0.068 3-0.181 7. AMOVA(Analysis of molecular variance) showed that 63.62% of genetic variation resided within families, while 36.38% of genetic variation resided between families, representing the genetic differentiation index of Fst 0.363 8. Via Fst, the Nm 0.937 2. The Litopenaeus vannamei for examination was on a high level of genetic diversity, and had some indeed selective capacity. Fst showed that the most genetic variation resided within families, Nm showed that limited gene flowing was the main cause of the genetic variation, which indicated the whole 35 families formed a relatively independent system during breeding. The cluster analysis declined the evolution relationship among families, which could provide a basis for the future breeding work.