关键词: 虹鳟（Oncorhynchus mykiss）；遗传结构；遗传分化；MHC

Abstract:

Oncorhynchus mykiss was cultured all over the world, this paper analyzed the genetic variation of MHC\|DAB intron 2 sequences (308 bp) in Gansu golden trout, Donaldson rainbow trout and USA Golden trout using PCR\|SSCP. 11 different nucleotide sequences（Ⅰ~Ⅺ）were detected from 108 positive clones, a maximum of 4 alleles were amplified from one single individual. Allele Ⅱ, Ⅲ and Ⅵ were presented in all the 3 populations. Ⅳ was only presented in Donaldson rainbow trout; Ⅶ only presented in Gansu golden trout; Ⅸ, Ⅹ and Ⅺ only presented in Golden trout. In Gansu golden trout, Donaldson rainbow trout and Golden trout, the nucleotide polymorphic sites were 17, 19 and 22. The nucleotide diversities (Pi) were 0.005, 0.008 and 0.013. The average numbers of nucleotide differences (K) were 1.200, 2.000 and 3.333, respectively. The genetic distance of Gansu golden trout and Donaldson rainbow trout was the smallest (0231), while that of Gansu golden trout and Golden trout was the largest (0.539). The genetic differentiation that compared any 2 of the 3 populations all up to the standard of population division (D＞0.05). The genetic differentiation index (GST) of the 3 populations was 0.097, indicating that the variation mainly came from the inter\|individual of the population.

Key words: Oncorhynchus mykiss, genetic structure, genetic differentiation, MHC