广西合浦珠母贝3个不同群体遗传关系分析  

Genetic Relationship among Three Populations of Pearl Oyster Pinctada fucata ssp.martensii in Guangxi,China

作　　者：邹杰 彭慧婧[1,2] 郑德斌 张守都[4] ZOU Jie;PENG Huijing;ZHENG Debin;ZHANG Shoudu(Guangxi Academy of Sciences,Nanning 530000,China;Guangxi Institute of Oceanology Co.,Ltd,Beihai 536000,China;Tianjin Bohai Sea Fisheries Research Institute,Tianjin 300457,China;Marine Science Research Institute of Shandong Province,Qingdao 266000,China)

机构地区：[1]广西科学院,广西南宁530000 [2]广西海洋研究所有限责任公司,广西北海536000 [3]天津渤海水产研究所,天津300457 [4]山东省海洋科学研究院,山东青岛266000

出　　处：《水产科学》2023年第3期466-473,共8页Fisheries Science

基　　金：广西创新驱动发展专项(桂科AA19254008);广西重点研发项目(桂科AB18294001);北海市科技计划项目(北科合201777036).

摘　　要：为探索广西合浦珠母贝群体内杂交组合方式,分别从北海野生群体(F_(1))、选育群体(F_(4))和养殖群体中随机挑选2龄种贝样本15个,进行简化基因组测序,通过单核苷酸多态标记解析3个群体的遗传关系。研究结果显示,获得超过585000个单核苷酸多态标记,野生群体、选育群体和养殖群体的观测杂合度分别为0.1975、0.1679和0.1783,期望杂合度分别为0.2545、0.2469和0.2732,平均近交系数分别为0.2075、0.3449和0.3465,多态信息含量分别为0.2032、0.2089和0.2241,选育群体近交系数与养殖群体相近,野生群体和养殖群体的群体遗传多态高于选育群体。系统进化树和主成分分析显示,选育群体与养殖群体部分样品亲缘关系较近。选育群体和养殖群体之间的遗传分化指数最低,部分亲本同源的可能性较大;野生群体、选育群体和养殖群体的平均长纯合片段数分别为59.1、49.5个和56.6个,长纯合片段平均长度分别为0.312、0.313Mb和0.311Mb,平均单核苷酸多态标记含量分别为59、50和73,近交系数FROH分别为0.0149~0.0240、0.0159~0.0201和0.0170~0.0246,反映3个群体的真实近交水平较低;野生群体、选育群体和养殖群体的整个染色体内连锁不平衡衰减距离分别为0.4、0.4kb和0.2kb(r2=0.2),衰减速度为养殖群体>野生群体>选育群体,选育群体衰减速度最慢,可能与人工选育有关。以上结果表明,广西合浦珠母贝可采用野生群体×选育群体或野生群体×养殖群体的杂交组合方式开展群体内杂交。本研究结果可为广西合浦珠母贝育种中的亲本选择提供参考。In order to explore the cross population hybridization of pearl oyster Pinctada fucata ssp.martensii in Guangxi,15 samples of 2-year-old pearl oyster were randomly selected from the wild population(F_(1)),the breeding population(“Haixuan No.1”F_(4))and the cultured population in the Beihai were used for double-enzyme digestion by Sea151-end EcoRⅠ(G^AATTC)and 2-end NlaⅢ(Hin1Ⅱ,CATG^),and then 500 ng of qualified DNA samples were constructed using ddRAD library construction method.The pair-end sequencing library was used in the length of 300-500 bp to analyze the genetic relationship among the three populations through single nucleotide polymorphism(SNP)markers.More than 585000 SNPs of the 3 populations were statistically obtained,with the observed heterozygosity of 0.1975,0.1679 and 0.1783,the expected heterozygosity of 0.2545,0.2469 and 0.2732,average inbreeding coefficient of 0.2075,0.3449 and 0.3465,and the polymorphism information content of 0.2032,0.2089 and 0.2241.The inbreeding coefficient of breeding population was close to cultured population,and there was higher genetic polymorphism in wild population and cultured population than that in the breeding population.The phylogenetic tree and PCA analysis revealed that some samples of breeding population and cultured population had close genetic relationship.Fst analysis showed that the minimal genetic differentiation index was observed between breeding population and cultured population,indicating that some parents were likely to be homologous.The wild population,breeding population and cultured population had average number of runs of homozygosity(ROH)of 59.1,49.5 and 56.6,the average length of ROH 0.312 Mb,0.313 Mb and 0.311 Mb,and the average SNPs content 59,50 and 73,the range of F ROH 0.0149-0.0240,0.0159-0.0201 and 0.017-0.0246,respectively,indicating that the real inbreeding phenomenon of each population was not obvious.The average linkage disequilibrium(LD)decay distances were 0.4 kb in wild population,0.4 kb in breeding population and 0.2 kb

关 键 词：合浦珠母贝 杂交 单核苷酸多态 遗传分化 长纯合片段 

分 类 号：S968.3[农业科学—水产养殖]