Microsatellite-based genetic and growth analysis for a diallel mating design of two stocks of the clam, Meretrix meretrix.

摘要

To determine the potential for productive efficiency and genetic improvement in the clam (Meretrix meretrix), four populations were produced from a diallel mating of two different geographical stocks (SD and JS). The genetic parameters at nine novel microsatellite loci indicated that the numbers of alleles, observed heterozygosity and polymorphic information content of the reciprocal cross populations (SDJS and JSSD) were larger than those of the pure populations (JSJS and SDSD). The values of Nei's unbiased genetic distance and F_ST revealed that the largest genetic divergence was between the two pure populations (D_C=0.2993, F_ST=0.1438) and the smallest was between the two reciprocal cross populations (D_C=0.1093, F_ST=0.0583). In addition, the mean shell lengths of the reciprocal cross populations were significantly larger than that of the pure populations by 1.577 mm (P<0.05), and the same trend was observed in the other traits. A significant maternal effect was revealed after analysis of the effects of egg origin and mating strategy on the four traits. Heteroses for all the traits were detected in the reciprocal cross populations. Our research implies an extensive development potential in productive efficiency and genetic improvement for M. meretrix.