Using microsatellite markers to identify heritability of Pacific whiteleg shrimp Litopenaeus vannamei

Pacific whiteleg shrimp (Litopenaeus vannamei) is an economically relevant shrimp species in many Asian countries. The specific objective of the current research was to assess microsatellite markers in screening the fast-growth of domesticated L. vannamei stocks to establish a founder population for breeding-selection plans. The postlarvae produced by the reproduction of second generation broodstock were cultured in the same conditions throughout a five months growing period. Ninety juvenile shrimp were selected from the slow-, medium- and the fast-growth groups, and ten microsatellite markers were used to investigate their genetic diversity, and to understand the improvement of a breeding-selection scheme. Ten polymorphic loci (markers) (M1-M10) were produced at ten loci in this sample, among them Primer M8 was the highest polymorphic locus and M7 was the lowest one. A specific locus was found in the fast-growth group using Primer M5. The longest genetic distance (0.481) was determined between the fast- and medium-growth groups and the shortest (0.098) was between the slow- and medium-growth groups; therefore, the largest genetic identity (0.946) was observed between the slow- and medium-growth groups and the smallest (0.667) was observed between the medium- and fast-growth groups. The Unweighted Paired Group with Arithmetic Average (UPGMA) dendrogram based on Nei's genetic distances provided two different groups; the first consist of the slow- and medium-growth groups and the second the fast-growth group. Selection response and realized heritability for growth were 11.55% and 31.26%, respectively. Therefore, this set of microsatellite markers would provide a useful tool in shrimp breeding schemes.