Microsatellite Marker Analysis On Cultivated Groups And Artificial Meiogynogenetic Groups Of Pseudosciaena Crocea

In this paper, microsatellite markers were used to analyze the genetic diversity of five cultured groups of large yellow croaker (Pseudosciaena crocea) in Fujian. And we analyzed the gene heterozygosity, alleles and genotypes of large yellow croaker with different growth speed and the correlation with the growth-related traits. In the meantime, we studied the efficiency of artificial meio-gynogenesis to pure gene in large yellow croaker.In first study, sixteen microsatellite markers were used to analyze the genetic diversity of five cultured groups of large yellow croaker in Fujian. The results showed that among the 5 cultured groups the average number of alleles (A) was 4.9 (Xiapu groups, XP), 5.1 (Lianjiang groups, LJ), 4.9 (Luoyuan groups, LY), 4.5 (Ningde groups, ND) and 5.0 (Fuding groups, FD), respectively; the average number of effective allele (Ne) was 3.34 (XP), 3.43 (LJ), 3.32 (LY), 2.92 (ND) and 3.41 (FD), respectively; the value of average observed heterozygosity (Ho) was 0.768 (XP), 0.760 (LJ), 0.748 (LY), 0.665 (ND) and 0.793 (FD), respectively; the value of average excepted heterozygosity (He) was 0.679 (XP), 0.691 (LJ), 0.678 (LY), 0.633 (ND) and 0.684 (FD), respectively; and the value of average polymorphism information content (PIC) was 0.616 (XP), 0.628 (LJ), 0.616 (LY), 0.571 (ND) and 0.621(FD), respectively. The value of Fst was 0.0113 to 0.0336 which indicated that genetic differentiation between the groups was comparatively lower. The P value of Hardy-Weinberg equilibrium showed that the five groups departed from equilibrium partially. At the same time, Nei's standard genetic distance was calculated and UPGMA dendrogram was constructed for the five groups.In second study, ten micromsatellite loci were investigated in 119 individuals of large yellow croaker with different growth speed. Gene heterozygosity of each individuals and the correlation with the growth-related traits were calculated, and the results showed that the gene heterozygosity for each individuals was not significantly correlative with the body weight and body length. An ANOVA procedure of SPSS was used to analyze the effects of these 10 microsatellites on body weight and body length, and discovered 7 loci (LYC0004, LYC0008, LYC0011, LYC0013, LYC0015, LYC0027 and LYC0036) that had a significant impact on growth-related traits. Alleles and genotypes with favorably effect on growth-related traits were determined.In third study, the efficiency of artificial meio-gynogenesis to pure gene in large yellow croaker was studied through analyzing the homozygosity of microsatellite loci in the meio-gynogenetic populations for generation one (meio-G1) and generation two (meio-G2). The results showed that the average homozygosity among the fifteen analyzed loci were 0.661 and 0.803 in meio-G1 and meio-G2, respectively, which is much higher than that in the natural mating population (0.376 for the average homozygosity). The average similarity coefficient between individuals within meio-G1 and meio-G2 were 0.5903 and 0.8672, respectively, which is also higher than that in the natural mating population (0.4687 for the average similarity index between individuals). Besides, seven out of analyzed loci (46.7%) were fixed in meio-G2, showing that the homozygosity of most genes can be accelerated by inducing meio-gynogenesis in large yellow croaker. However, purity is hard to achieve in some loci for their telomerical location. For these loci, homozygosity can be gained by inducing mito-gynogenesis or control cross between individuals having same genotype.