草鱼野生与选育群体线粒体DNA控制区D-loop遗传变异分析  

GENETIC VARIATION OF MITOCHONDRIAL DNA D-LOOP REGION IN WILD AND BREEDING POPULATIONS OF GRASS CARP

作　　者：王沈同 张猛[1] 党云飞[1] 李立森[1] 黄文吉[1] 方圆[1] 王丰[1] 沈玉帮[1] 李家乐[1] WANG Shen-Tong;ZHANG Meng;DANG Yun-Fei;LI Li-Sen;HUANG Wen-Ji;FANG Yuan;WANG Feng;SHEN Yu-Bang;LI Jia-Le(Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education,Shanghai Ocean University, Shanghai 201306, China)

机构地区：[1]上海海洋大学省部共建水产种质资源发掘与利用教育部重点实验室,上海201306

出　　处：《水生生物学报》2017年第5期947-955,共9页Acta Hydrobiologica Sinica

基　　金：现代农业产业技术体系(CARS-46-04);上海市工程中心提升项目(16DZ2281200);通威产学研项目(TW2014F003)资助~~

摘　　要：为探究经过2个选育世代后选育群体遗传多样性和遗传结构的变化,研究对4个野生群体(邗江、九江、石首和吴江)和2个选育世代(F1和F2)进行了线粒体DNA控制区(D-loop)序列的遗传变异分析。实验结果表明,4个野生群体在单倍型数目(H)、单倍型多样性(Hd)、核苷酸多样性(π)、平均核苷酸差异数(K)水平上均高于2个选育世代,在2个选育世代内表现为F1代群体的核苷酸多样性(π)和平均核苷酸差异数(K)大于F2代群体,但单倍型多样性(Hd)小于F2代群体;单倍型分析结果表明,6个群体间无共享单倍型,4个野生群体间共发现2种共享单倍型(Hap1和Hap3),石首群体和2个选育世代共享1种单倍型(Hap15);遗传分化指数(F_(st))分析结果表明,邗江、九江、吴江3个野生群体和2个选育世代间存在较大的遗传分化(F_(st)范围为0.41475—0.55128),石首群体与F1代群体之间存在较小的遗传分化,与F2代群体之间存在中等水平的遗传分化,同时F1代群体与F2代群体之间存在较小的遗传分化;基于6个群体276个个体构建的邻接(Neighbor-Joining,NJ)进化树和基于27种单倍型构建的单倍型网络图也得到了相似的结论,即邗江、九江、吴江3个野生群体和2个选育世代间的亲缘关系较远,石首群体和2个选育世代两两之间的亲缘关系较近。以上结果表明,经过2个世代的选择育种,选育群体的遗传结构已发生了变化,并且随着选育的进行,选育世代的遗传多样性下降的较为明显,这警示着我们在今后的育种工作中应适当改变现有的选育方案,并实时监测选育群体的遗传多样性,以便为今后进一步的选育工作打下坚实的基础。To evaluate the genetic diversity and genetic structure of grass carp(Ctenopharyngodon idella),we analyzedthe genetic variation of mitochondrial DNA D-loop region among four wild populations(Hanjiang,Jiujiang,Shishou,Wujiang)and two domesticated populations after two generations(F1and F2)of selective breeding.The results showedthat the wild populations had higher number of haplotype(H),haplotype diversity(Hd),nucleotide diversity(π)and averagenumber of nucleotide differences(K)compared with the domesticated populations.Between the bred populations,F1generation was higher than F2generation in the aspects of nucleotide diversity(π)and average number of nucleotidedifferences(K),but haplotype diversity(Hd)in F1generation was lower than F2generation.Haplotype analysisshowed that all six populations did not share a haplotype.By contrast,the four wild populations shared two haplotypes(Hap1and Hap3).The Shishou population and two domesticated populations shared one haplotype(Hap15).Geneticdifferentiation index(Fst)analysis showed that there was great genetic differences between wild(Hanjiang,Jiujiang,Wujiang)and domesticated populations(range Fst from were0.41475to0.55128).Genetically,Shishou population wasclosely related with F1population,but its relationship with F2was only moderate.Moreover,the genetic differentiationlevel between two breeding populations was small(Fst=0.05741).The analysis of neighbor-joining phylogenetictrees based on276individuals among six populations and haplotype network graph based on27haplotypes indicatedthe wild populations(Hanjiang,Jiujiang,Wujiang)had a distant relationship with those domesticated populations.AlthoughShishou population and two breeding populations were more closely related.The above results showed thatamong the two domesticated populations,the genetic structure has already changed after two generations of selectivebreeding,and the genetic diversity also decreased with the development of the breeding program.The results also urgeus that the current breeding strategy should

关 键 词：草鱼 选育群体 野生群体 mtDNA D-LOOP 遗传变异 

分 类 号：Q349.1[生物学—遗传学]