Microsatellite Marker Analysis on Genetic Variation of the Ridgetail White Prawn Exopalaemon carinicauda Backcross Populations

Abstract:

In order to analyze genetic effect of the ridgetail white prawn (Exopalaemon carinicauda) backcross families, 25 microsatellite loci were selected to detect the genetic characteristics of three backcross family A, B, C, generated by our laboratory. The results showed that among A, B and C families, the average number of alleles (Na) were 2.21, 2.18 and 2.09, the observed heterozygosity (Ho) were 0.3805, 0.3703 and 0.2489, the expected heterozygosity (He) were 0.3629, 0.3998 and 0.2503 and the polymorphism information content (PIC) were 0.3257, 0.3391 and 0.2585 respectively. Compared to the wild and hybrid population, the genetic diversities of the backcross families were greatly reduced which belonged to moderate or low polymorphism. 62 alleles were obtained in the three backcross families in total using 25 loci. Specifically, 56, 54 and 51 alleles were obtained in A, B and C backcross families, respectively. In addition, there were 39 common alleles in the three backcross families. Six loci have homozygosity in all backcross families (ECL10 in A, B and C families). The average homozygous rate was 53.86%, 56.53% and 63.33% respectively, which showed that the purification rate of gene was rapid and the backcross is suitable for selective breeding in E. carinicauda.