一代远近交选育对团头鲂遗传变异的影响的初步研究

A primary study on the effect of one-generation outbreeding and inbreeding selection on the genetic variation of Megalobrama amblycephala

测定了团头鲂4个选育群体和一个对照群体(养殖场人繁群体)的14个座位构成的7种酶的遗传变异。两个远交群体和两个近交群体的多态位点比例均为21.43%,对照组亦为21.43%;两个远交群体的平均杂合度分别为0.0944和0.0923,两个近交群体分别为0.0997和0.1021,四群体平均为0.0971,而对照组为0.0941。远交群体与对照组之间的遗传距离(Nei 氏值)较大,为0.0060;近交群体与对照组之间的遗传距离较小,为0.0031。试验结果显示,一代选育已能使团头鲂的遗传变异产生微小的、但可监测到的改变。

The genetic variation of 7 enzymes coded by 14 loci were analyzed for 4 selected populations and 1 control(hatchery) population of blunt snout bream (Megalobrama amblycephala).There was no difference in the mean proportion ofpolymorphic loci,all were 21.43%.The average heterozygosity per locus were 0.0944 and 0.0923 in the 2 outbreedingpopulations.0.0997 and 0.1021 in the 2 inbreeding populations respectively.their overall mean was 0.971,but in thecontrol population was 0.0941.The Nei genetic distance between the outbreeding and control populations was bigger-0.0060 and between the inbreeding and control population was smaller—0.0031.These results indicated that one genera-tion selection could cause a very little,but detectable change in genetic variation of blunt snout bleam.