三疣梭子蟹选育家系微卫星分析

采用微卫星标记技术分析不同世代三疣梭子蟹选育家系的遗传结构。利用16个多态性微卫星位点分析了三疣梭子蟹家系F1到F4 4个选育家系的遗传结构与遗传多样性变化情况。结果显示,随着选育的进行,4个世代家系遗传多样性指标值逐渐下降,F1到F4 16个微卫星位点的平均多态信息含量从0.675 3下降到0.406 1,平均等位基因数从3.500 0下降到2.133 3,平均观测杂合度从0.643 5下降到0.4774,平均等位基因纯合率从0.566 9下降到0.402 4。对各个位点进行H-W检验,每个世代出现不同程度的平衡偏离。对各家系进行F-检验,结果表明,各家系存在不同程度的遗传分化,19.07%的遗传分化来自群体间,80.93%的遗传分化来自群体内。另外,对FIS值的计算显示,4个家系在整体上均表现为一定程度的杂合子缺失,其中F4有12个位点、F3有6个位点、F2有3个位点、F1有8个位点处于杂合子缺失状态。遗传距离逐渐增加,相邻世代间的遗传相似性逐步升高。经过连续4代的选育,选育群体的遗传基础逐步得到纯化,基因型逐渐趋向纯合、稳定,经进一步的选育可望获得较稳定的品系。

SSR analysis of selected populations of inbred Portunus

The genetic structure of different trituberculatus generations was analyzed based on microsatellite DNA markers.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 0.675 3 to 0.406 1,the average allele number from 3.5 to 2.133 3,the average heterozygosity from 0.643 5 to 0.477 4 and the average rate of allele homozygous from 0.566 9 to 0.402 4.We tested all loci for H-W,there are different degrees of deviation from equilibrium in each generation.There are different degrees of genetic differentiation by F-test for each system,and the results show that 19.07% of the genetic differentiation is among populations,80.93% of the genetic differentiation is within the group.In addition,the F_IS value calculations show that four families on the whole are expressed as a certain degree of heterozygosity,in which F₄ has 12 sites, F₃ has six sites, F₂ has three sites, F₁,8 loci in heterozygosity status.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 and genotype was gradually moving towards homozygous and stable.We expected to get more stable strains with further breeding.