安徽省草鱼养殖群体遗传多样性及遗传结构分析

The genetic diversity and population structure of cultured Ctenopharyngodon idella in Anhui Province

通过微卫星分子标记对来自安徽省4个草鱼养殖群体进行遗传分析。结果表明,7个微卫星位点均具有高度多态性(PIC=0.863~0.926),4个草鱼群体均显示出较高的遗传多样性(He=0.886 1~0.911 4)。AMOVA分析显示,大多数遗传变异存在于草鱼群体内(97.6%),群体间的遗传变异仅为2.4%。遗传分化和遗传距离分析显示,4个群体整体分化水平较低(Fst<0.05),怀远和滁州群体遗传分化最小(Fst=0.013 7),遗传距离最近(Dn=0.269 8),池州和无为群体遗传分化最大(Fst=0.042 5),遗传距离最远(Dn=0.591 6)。系统进化树显示,怀远和滁州群体亲缘关系最近,与池州最远。此外,4个养殖场内部草鱼均存在近亲繁殖现象。建议4个养殖场及时更新亲本,增加繁殖亲本的数量,避免近交衰退带来的风险。

Genetic analysis was conducted on four grass carp breeding populations from Anhui Province by microsatellite. The results showed that 7 microsatellite loci were highly polymorphic(PIC=0.863-0.926), and 4 grass carp populations showed high genetic diversity(He=0.886 1-0.911 4). AMOVA analysis showed that most of the genetic variation was found within the grass carp population(97.6%), and only 2.4% was found among populations. Genetic differentiation and genetic distance analysis showed that the overall differentiation level was low(Fst<0.05), Fst between Huaiyuan(HY) and Chuzhou(CZ) populations was lowest at 0.013 7, while that between Chizhou(GC) and Wuwei(WW) was the highest at 0.042 5. The genetic distance between HY and CZ population was the lowest at 0.269 8, while that between GC and WW population was the highest at 0.591 6. UPGMA phylogenetic tree was constructed based on Nei’s genetic distance showed that the relationship between HY and CZ was the closest. In addition, inbreeding was found in all the four detected farms. Our present study was suggested that the four farms should update parents fish in time, increase the number of breeding parents and avoid the risk of inbreeding depression.