从江及周边地区稻田鲤的遗传结构及系统发育关系

为探究贵州从江及邻近的榕江、黎平和锦屏以及广西三江、湖南的通道和靖州等地稻田鲤Cyprinus carpio Linnaeus的遗传结构及系统关系, 研究基于mtDNA Cyt b基因测序技术对6个地理群体进行了分析。447尾稻田鲤中共界定出29种Cyt b基因序列单倍型, 结合NCBI中鲤同源序列的系统发育和序列比对分析表明, 从江及邻近苗侗族地区稻田鲤是一个含欧亚2大谱系、3个鲤亚种和多个母系血统成分的混合群体, 主体类群是华南鲤C. carpio rubrofuscus, 同时混有欧洲鲤C. carpio carpio和远东鲤C. carpio haematopterus, 遭受国内外鲤养殖品种的遗传渗析。遗传多样性分析显示, 欧洲鲤亚种群体为低H_d低π, 遗传多样性贫乏, 远东鲤和华南鲤2个亚种群体呈高H_d低π特点。华南鲤6个稻田群体除锦屏为低H_d低π外, 其余都为高H_d低π, 从江的H_d最高, 黎平的π最高。遗传分化和分子方差(AMOVA)分析显示, 谱系间和亚种间存在显著的遗传分化(P<0.001), 锦屏和三江与其他群体存在中等-高度的分化等级, 其余群体间分化较弱, 群体间变异贡献率为16.69%, 群体内为81.14%。综合分析表明, 从江及邻近地区稻田鲤群体间存在有限的遗传交流, 群体内和群体间有不同的遗传结构。研究丰富了该地区稻田鲤遗传背景资料, 可为湘黔桂交界苗侗族地区稻田鲤的种质资源鉴定与保护提供理论依据。

GENETIC STRUCTURE AND PHYLOGENETIC RELATIONSHIP OF RICE FIELD CARP (CYPRINUS CARPIO LINNAEUS) IN CONGJIANG AND SURROUNDING AREAS

The 6 geographic populations were analyzed by using mtDNA Cyt b gene sequencing technology for exploring the genetic structure and phylogenetic relationship of rice carp Cyprinus carpio Linnaeus in Congjiang and surrounding areas including Rongjiang, Liping, Jinping, Sanjiang, Tongdao and Jinzhou in China. Among the 447 individuals of rice field carp, there were totally 29 Cyt b gene sequence haplotypes being defined. It was revealed by combining with the phylogeny and sequence comparison analysis of carp homologous sequences in NCBI that the rice field carp in Congjiang and neighboring Miao-Dong areas was a large mixed group containing 2 Eurasian pedigrees, 3 carp subspecies and multiple maternal lineage components, dominated by South China carp C. carpio rubrofuscus. At the same time, the group was also mixed with European carp C. carpio carpio and Far East carp C. carpio haematopterus, which indicated that indigenous rice field carp had experienced genetic invasion by domestic and foreign carp breeding varieties. It was revealed by the genetic diversity analysis that the European carp subspecies population was low H_d and low π type and genetic diversity was poor while the two subspecies populations of Far East carp and South China carp showed the characteristics of high H_d and low π. Among the 6 rice field populations of South China carp, except for Jinping in low H_d and low π, the rest were all high H_d and low π with Congjiang’s H_d being the highest and Liping’s π being the highest. It was shown by genetic differentiation and molecular variance (AMOVA) analysis that there was significant genetic differentiation between lineages and subspecies (P<0.001). Moreover, Jinping and Sanjiang had a medium-high level of differentiation with other populations with the rest populations being weak in differentiation. The contribution rate of variation among these groups was 16.69% and the figure was 81.14% within the groups. It was indicated by comprehensive analysis that there was limited genetic flows among rice field carp populations in Congjiang and adjacent areas with different genetic structures within and between populations. The research helped to enrich the genetic background data related to the rice field carp in the area, which was conductive to providing a theoretical basis for the identification and protection of rice field carp germplasm resources in the Miao-Dong ethnic area at the junction of Hunan, Guizhou and Guangxi Provinces.