三疣梭子蟹遗传连锁图谱的初步构建

Construction of a genetic linkage map of Portunus trituberculatus

利用AFLP和SSR标记技术结合"拟测交"策略,以三疣梭子蟹莱州湾、舟山野生群体杂交(1♂×3♀)产生的F2代家系为作图群体,初步构建了三疣梭子蟹雌、雄性遗传连锁图谱。用经过筛选的60对AFLP引物和3对SSR引物对亲本及108个F2代个体进行遗传分析,共得到母本分离标记214个,其中155个标记(AFLP标记153个,SSR标记2个)符合1∶1孟德尔分离规律;父本分离标记195个,139个标记(AFLP标记138个,SSR标记1个)符合1∶1孟德尔分离规律。雌性图谱包括100个遗传标记,分布在9个连锁群,6个三联体,15个连锁对,图谱总长度为1544cM,标记平均间隔22.0cM,总覆盖率为52.9%。雄性图谱包括71个遗传标记,分布在6个连锁群,6个三联体,11个连锁对,图谱总长度1174.2cM,标记平均间隔24.0cM,总覆盖率为49.5%,图谱中遗传标记分布比较均匀。

Genetic linkage map of Portunus trituberculatus was constructed using ＂double pseudo-testcross＂ strategy with AFLP and SSR molecular labeling techniques.In this study,maternal and paternal broodstock were sampled from Laizhou Bay and Zhoushan Island wild populations of P.trituberculatus,respectively.Through the directional mating（1♂×3♀）,the wild parents were used to generate F1 family.The 108 progenies of directional mating F2 family coming from sisterhood intercross between F1 family and its parents were used as experiment materials.Sixty AFLP primer combinations and 3 pairs of SSR primers were screened to produce 214 maternal markers and 195 paternal markers.There were 155 markers which included 153 AFLP markers and 2 SSR markers segregating as 1∶1 model from 214 maternal markers.139 markers which contained 138 AFLP markers and 1 SSR marker segregated in 1∶1 model in 195 parental markers.The female linkage map consisted of 100 markers distributed in 9 linkage groups（more than three markers）,6 triplets and 15 doublets,which covered a total length of 1 544 cM.Average marker spacing of female linkage map was 22.0 cM and the observed genome length accounted for 52.9% of the estimated genome length.The paternal linkage map consisted of 71 markers distributed in 6 linkage groups,6 triplets and 11 doublets,spanning the distance about 1 174.2 cM with average marker spacing of 24.0 cM and its genome coverage was 49.5%.The Pearson analysis results showed that all the genetic markers distributed in linkage map uniformly.This study provided a starting point for further construction of high density linkage maps,as well as for the mapping of functional genes and the location of quantitative trait loci（QTL）in P.trituberculatus.