[Genetic diversity and structure of 15 full-sib families of <i>Litopenaeus vannamei</i> based on SSR markers].

To clarify the genetic diversity and structure of the nucleus population of F1-generation <i>Litopenaeus vannamei</i>, this study utilized 15 pairs of highly polymorphic microsatellite primers to analyze the simple sequence repeat (SSR) markers and genetic diversity in 15 full-sib families of <i>L</i>. <i>vannamei</i>. A total of 112 alleles (<i>N</i>_a) and 60.453 effective alleles (<i>N</i>_e) were identified among the selected 15 SSR loci, with the average polymorphic information content (PIC) of 0.648. The average <i>N</i>_<i>e</i>, observed heterozygosity (<i>H</i>_o), and expected heterozygosity (<i>H</i>_e) in the 15 F1 families varied from 1.925 to 2.626, 0.425 to 0.783, and 0.403 to 0.572, respectively. The 15 full-sib families were primarily clustered into three categories in the phylogenetic analysis, with the genetic distance between families ranging from 0.252 to 0.574. Additionally, the genetic differentiation coefficient (<i>F</i>_st) among the families varied from 0.112 to 0.278, indicating substantial genetic differentiation. Overall, this study suggested that the genetic diversity of the 15 full-sib families was moderate, providing valuable genetic insights for the subsequent breeding initiatives aimed at enhancing the tolerance of <i>L</i>. <i>vannamei</i> to high levels of soybean meal.