Abstract:

he present studies reported genetic diversity and parental size of the fourth generation selected line by using microsatellite marker system with an aim to avoid depression on traits of the line. The line was developed by sampling parental breeders with superior growth rate from the third generation selected line in September of 2010. The female and male breeder numbers were 42 and 38, respectively. In June of 2011, 90 individuals were randomly sampled from the selected line and subjected to the experiment where genetic diversity and full-sibs relationships were analyzed by using forty-five microsatellite loci. A total of 186 alleles were detected and the number of the alleles at each locus ranged from 2 to 9 with a mean of 4.13. The average observed heterozygosity, average expected heterozygosity, Shannon diversity index and PIC values were 0.543, 0.542, 1.012 and 0.491, respectively. 30 full-sibs families were obtained on the basis of likelihood ratio algorithm of gene frequency. 75% breeders were contributed to progeny. Inbreeding coefficient increment was 0.83% between the third and fourth generation selected lines. The inbreeding coefficient of the fourth generation selected line was 3.27%. These results showed that the selected group had a high level of genetic diversity and microsatellite marker system was effective to estimate parental size.