The Genetic Variation Analysis Of Inbred Portunus Trituberculatus Family

This article used Portunus trituberculatus of inbred family for the experimental material.We make study on Body Weight by the use of correlation analysis and path analysis.We also studied on the genetic diversity and the degree of inbreeding of Portunus trituberculatus in different years using microsatellite DNA markers. The main results are as follows:We randomly selected 30 individuals from 05-G4-1 family of Portunus trituberculatus,and sampled for measuring five morphometric traits including full carapace width(X1),carapace width(X2),carapace length(X3),body height(X4)and body weight(Y).By correlation and path analysis,the results show that the correlation coeficients of each morphological trait to body weight are all at significant(P<0.05)or extremely significant level(P<0.01).The path coefficients in three years all reach significant level(P<0.05),the diversification of determination coeficients analysis is consistent with that of path . The morphometric traits which reach level of significance(P<0.05) are used to establish the multiple regression equations,which are Y=-52.467+0.301X1+0.201X2+0.252X3+0.439X4;Y=-82.567+0.177X1+0.170X2 + 0.325X3 + 0.225X4 ; Y= - 81.261 + 0.283X1 - 0.071X2 + 0.161X3 +0.361X4。Constructed under the FIASCO method Portunus microsatellite enriched library, Microsatellite-containing DNA sequence of 71pairs of primers and polymorphism screening was carried out ,selected 21 pairs of microsatellite polymorphic primers for Portunus swimming crab wild population genetic diversity of 30 individuals testing and evaluation of tags.A total of 21 sites were 188 alleles amplified per locus on average 8.9 alleles.Different primers were quite different alleles,ranging from 3 to 13,which Pot8, Pot37, Pot48, Pot53, Pot54, Pot66 six sites were obtained 11,12,12,11,13,11 alleles,but Pot46 only received 3 alleles.Allele size distribution in the 131~312bp,basically in line with the design theory primer product length.21microsatellite loci of expected heterozugosity in the range of 0.659~0.889,PIC values higher than 0.5,indicating that they have a high heterozygosity.Can be used for population genetic structure of Portunus analysis,trituberculatus breeding, germ-line assessment of microsatellite DNA for more information.We carried out the genetic analysis on wild population,inbred 05-A2-1 and 05-G4-1 of Portunus trituberculatus by the use of 16 microsatellite primers. The results showed that there were 16 microsatellite locis which were polymorphic in the wild population,but there were only 9 polymorphic locis in the 05-A2-1 and 11 polymorphic locis in the 05-G4-1. In the wild population,136 alleles were detected and there were 52 alleles in the 05-A2-1,47 alleles in the 05-G4-1. The inbred homozygous were high on average,of which 05-A2-1 was 55.87%,05-G4-1 was 56.69% and the average rate is 38.37% in the wild population. The inbred's average heterozygosity and polymorphic information content is lower than the wild population. Between inbred 05-A2-1 and 05-G4-1,the population genetic similarity index is the largest and the genetic distance is smallest,indicating the closest relationship between them. The inbred genetic diversity decreased significantly and already has a high genetic purity.Sixteen microsatellite markers were used to analyze the genetic structure and genetic diversity of the selected populations of inbred Portunus rituberculatus from F1 to F4. The results showed that the genetic diversity of the breeding population was decreasing . The the average polymorphism information content (PIC) of the 16 microsatellite markers decreased from 0. 6753 to 0.4061, the average allele number from 3.5 to 2.1333, the average heterozygosity from 0.6435 to 0.4774 and the average rate of allele homozygous from 0.5669 to 0.4024. Increasing genetic distance, adjacent genetic similarity between generations gradually increased. With the breeding, the results show that after 4 consecutive generations of breeding.The genetic basis of breeding gradually purified homozygous and genotype gradually moving towards stable.We are expected to get more stable strains with further breeding.