The Development And Application Of Ssr Markers Of Nibea Albiflora

Yellow drum?Nibea albiflora?is a kind of important economic fish in China.Based on yellow drum transcriptome sequencing data,microsatellite?SSR?markers for yellow drum were developed,and the SSR markers were applied to the genetic diversity analysis of three yellow drum groups.Furthermore,the homozygosity of gynogenesis F₁?GYF1?and gynogenesis F₂?GYF2?of yellow drum were analyzed by using 12 highly polymorphic SSR markers.Results summarized as follows:1.By using MISA program,12,254 SSR loci were identified from the transcriptome data of yellow drum.Among them,mononucleotides were the most frequent?42.70%?,followed by dinucleotides?32.11%?and trinucleotides?23.54%?,quadr-,penta-and hexa-nucleotides accounted for 1.60%,0.09%and 0.06%,respectively.120 SSR loci were chosen randomly for designing PCR primers,in which 78 primer sets produced strong PCR products matching their expected sizes,and 39 of them were polymorphic.The characteristics of 39 loci were estimated by using a sample of 30 individuals from South China Sea.The mean number of alleles was 6.23,and the mean effective number of alleles across loci was 3.630,and 26 loci were highly informative?PIC>0.5?.2.Eighteen polymorphic SSR markers developed in this study were selected for genetic diversity analysis in three yellow drum groups from the South China Sea?SOYD?,the East China Sea?EAYD?and selective breeding F4 group?XYYD?.Totally,197 alleles were found in all SSR markers and the average number per locus was 10.94.The mean effective number of alleles across loci was 5.905.The average of observed heterozygosity?H_o?was 0.4530 and the average of expected heterozygosity was 0.8132.The average of PIC was 0.7852.All the data were on the upper medium level,indicated that all of these yellow drum groups had higher genetic diversity.The value of PIC and H_o of XYYD group were below that of SOYD and EAYD groups.UPGMA clustering tree of three groups demonstrated that there were two different groups:one being composed of EAYD and XYYD groups,and the other of SOYD group.The results provided reference data for the establishment of yellow drum breeding strategy.3.Using 12 highly polymorphic micromsatellite markers to analyze the homozygosity?H_o?in gynogenesis generation?GYF1?and gynogenesis second generation?GYF2?groups.It showed that the value of N_a,N_e,H_o,Shannon-Weiner index and PIC in GYF1 were all higher than those in GYF2.Compared with GYF1,homozygosity of 10 loci in GYF2 showed increase and 4 loci were 100%in GYF2.The average homozygosity among the twelve analyzed loci was0.7994 in GYF2,which is 1.41 times of that in GYF1.It showed that the homozygosity of most genes can be accelerated by inducing meio-gynogenesis in yellow drum.However,purity is hard to achieve in some loci because of high recombination related to their far location to centromere.For these loci,homozygosity can be gained by using mito-gynogenesis and combining with the marker assisted breeding to screening for high pure degree of gynogenesis offspring individual for further breeding.