三疣梭子蟹莱州湾、舟山野生个体定向交配产生F2代家系的AFLP分析

AFLP analysis of F2 family generated by directional mating between wild Portunus trituberculatus from Laizhou Bay and Zhoushan Island

关键词:  三疣梭子蟹  定向交配F2家系  AFLP分析

Key words:  Portunus trituberculatus  Directional mating F2family  AFLP analysis

摘要:

以三疣梭子蟹莱州湾、舟山野生群体杂交（莱州湾♀×舟山♂）产生F2代家系63个个体及F1代亲本为实验群体，采用AFLP分子标记对其进行遗传分析。35对选择性引物共扩增出1 742个位点，其中分离位点为417个，不分离位点为1325个，多态位点比例为23.9％。在分离位点中，符合1∶1孟德尔分离比例的位点为226个，占总分离位点数的54.2％；偏离1∶1孟德尔分离比例的位点为31个，占总分离位点数7.4％。符合3∶1孟德尔分离比例的位点为128个，占总分离位点数的30.7％；偏离3∶1孟德尔分离比例的位点为32个，占总分离位点数的7.7％。家系内基因多样性指数为0.130，Shannon指数为0.193。遗传距离分析显示，子代个体与母本Nei’s遗传距离介于0.064-0.111之间，与父本Nei's遗传距离介于0.065-0.107之间。其中，63号个体与48号个体分别与父、母本亲缘关系最远。本实验中，偏分离位点比例属正常范围，杂交F2代家系遗传多样性偏低。本研究结果为三疣梭子蟹野生群体及家系遗传多样性分析，遗传连锁图谱构建等方面提供一定的技术支持。

Abstract:

Portunus trituberculatus is one of the most important fishery resources in China because of its high commercial value. In recent years, it has suffered from overfishing and various diseases, and the total resource of wild populations has decreased year by year. Considering for this situation, it is necessary to study the genetic diversity and genetic linkage map of P. trituberculatus. In this study, maternal broodstock and paternal broodstock were sampled from Laizhou Bay and Zhoushan Island wild population, respectively. Through directional mating (1♂×3♀), they generated F1 family. 63 individuals of F2 family came from sisterhood intercross between F1 family and these broodstock were used as experiment materials. The AFLP analyses showed that a total of 1 742 loci were produced,of which 417 loci were polymorphic, accounting for 23.9%. In these polymorphic loci, there were 226 (accounting for 54.2% of total segregating loci) loci segregating as 1∶1 Mendelian model while 31 (7.4%) loci segregating as distorted model.128 loci (30.7%) segregated as 3∶1 model and the numbers of 32 (7.7%) loci were distortion bands. Additionally, several AFLP bands which segregated neither as 1∶1 nor as 3∶1 were named with odd segregating loci. They were treated as non-segregating loci in order to reduce the influence of statistical error. Genetic diversity index of the F2 was 0.130, and Shannon genetic diversity index was 0.193. Analysis of distances showed that Nei’s genetic distance of family with male parent and female parent were between 0.064~0.111, 0.065~0.107 respectively. In the mean time, No63 individual was most distant from its male parent and No48 individual was most distant from its female parent. The main purpose of the study was to provide the technical support for genetic diversity analysis of wild populations or families and construction of high density genetic linkage map of P. trituberculatus.