基于微卫星标记的洞庭青鲫与三个鲫品系群体遗传多样性分析

GENETIC ANALYSIS OF DONGTINGKING CRUCIAN CARP AND OTHER THREE STRAINS OF CRUCIAN CARP BASED ON MICROSATELLITE MARKERS

选取12个微卫星标记对洞庭青鲫(Carassius auratus var.Dongtingking)、野生二倍体和三倍体鲫(C.auratus)、彭泽鲫(C.auratus var.pengzesis)4个鲫品系群体进行遗传多样性检测。在12个基因座位中,共检测出78个等位基因,其中14个为共有等位基因;每个座位检测到等位基因4—12个,平均等位基因数6.58个;4个鲫品系群体的平均观测杂合度(Ho)分别为0.633、0.750、0.800、0.717;平均期望杂合度(He)分别为0.502、0.713、0.757、0.602;平均多态信息含量(PIC)分别为0.364、0.599、0.637、0.470。上述结果表明,野生二倍体和三倍体鲫的遗传多样性较为丰富,以三倍体鲫的遗传多样性为最高;而洞庭青鲫和彭泽鲫养殖群体存在杂合度降低,遗传多样性下降的现象,以洞庭青鲫的遗传多样性为最低。基于遗传距离构建的UPGMA聚类树表明,洞庭青鲫与彭泽鲫两个养殖群体聚为一支,而二倍体与三倍体野鲫群体聚为另一支,说明洞庭青鲫与彭泽鲫之间亲缘关系较近,野生二倍体与三倍体鲫之间的亲缘关系较近。研究不同倍性鲫品系的遗传多样性,对于探讨鲫的多倍体起源演化以及鲫品系的种质资源保护和选育种实践具有重要意义。

We studied the genetic diversity of different strains of Carassius auratus by using microsatellite DNA markers for the Dongtingking crucian carps, the diploid and triploid wild crucian carps, and Pengze crucian carps. Twelve microsatellite markers were selected to analyze the four strains of Carassius auratus. A total of 78 alleles were identified in the four populations, of which 14 were in common. The number of alleles generated from each locus ranged 2-12, average 6.58. Results shows that the genetic diversity of the diploid and triploid wilds was richer than those in the bred ones as indicated in observed heterozygosity （Ho）, expected heterozygosity （He）, and polymorphism information contents （PIC）. Analysis based on genetic distance showed that Dongtingking crucian carp and Pengze crucian carp populations cluster in one group and the diploid and triploid crucian carps in another in UPGMA tress （unweighted pair-group methods with arithmetic means）. This study may serve as a reference for understanding their evolution to guild better breeding practice.