不同种群草鱼遗传结构的TRAP分析

应用TRAP(targetregionamplifiedpolymorphism)技术,对草鱼(Ctenopharyngodonidella)野生种群和两个人工养殖种群的遗传结构进行了比较。从15个引物组合中,筛选出7个扩增效果比较好的引物组合,在3个种群中共检测到103个扩增位点,其中野生种群、淡水中心种群和前洲种群的多态性位点分别为67、55和46,表明人工养殖草鱼种群的遗传多样性有所降低。与野生种群相比较发现,人工养殖种群仅33.98%位点的基因频率保持不变,表明人工养殖种群的遗传结构发生了改变。淡水中心种群、前洲种群与野生种群间的遗传距离分别为0.0421和0.0809。引物组合Ga5-800-E5扩增的结果发现,人工养殖种群中存在扩增位点明显减少的区域,这为寻找鉴定草鱼野生种群和养殖种群的遗传标记提供了依据。

Genetic Structure Analyses of Different Populations of Grass Carp (Ctenopharyngodon idella ) Using TRAP Technique

TRAP (target region amplified polymorphism) was used for comparison of genetic structures among three populations of grass carp (Ctenopharyngodon idella), one wild population from Jiangsu Hanjiang National Four Major Chinese Carps Seed Farm and two cultured populations from Freshwater Fisheries Research Center Aquatic Breeding plant and Wuxi Qianzhou Aquatic Breeding plant. Seven primer combinations selected from 15 primer combinations produced good amplified patterns and 103 amplified loci from three populations were obtained. The numbers of polymorphic loci in Hanjiang population, Freshwater Fisheries Research Center population and Qianzhou population were 67, 55, and 46 respectively. It indicated that genetic polymorphism decreased in two cultured grass carp populations. Compared with wild population, only 39.98% loci gene frequency kept being unchanged in two cultured ones. It showed that the genetic structure of cultured populations had changed. The genetic distances between wild population and two cultured populations were 0.0421 and 0.0809, respectively. With primer combination Ga5-800-E5, a region was detected in electrophoretic pattern in which the number of amplified loci reduced apparently in cultured populations. This will offer scientific basis for developing of molecular markers to distinguish wild population from cultured ones.