尼罗罗非鱼选育家系的遗传多样性研究

Genetic Diversity Analysis of Nile Tilapia Breeding Families

近年来,微卫星标记技术因其引物通用性强、检测快速、多态信息含量高等优点发展并成为各种物种基因组作图的首选标记。本文利用11个微卫星标记分析14个尼罗罗非鱼家系的遗传多样性,研究尼罗罗非鱼群体的遗传多样性和家系间的遗传关系。结果表明,11个微卫星位点扩增产物具有多态性,每个位点平均等位基因数为8.36;14个尼罗罗非鱼家系的平均多态信息含量、平均杂合度、平均有效等位基因数分别为0.499 3、0.558 3、2.608 0,表现为较高的遗传多态性。对14个尼罗罗非鱼家系间的遗传距离分析发现,家系NT207与NT213遗传距离最小,为0.204 4;家系NT208与NT210遗传距离最大,为0.760 9。14个尼罗罗非鱼家系间的平均遗传相似性指数为0.649 6,平均遗传距离为0.440 2。UPGMA系统树分析结果表明,家系NT215、NT218、NT210与NT211构成一个分支;家系NT214、NT203、NT206、NT207、NT213、NT217、NT209与NT216构成另一个分支;而家系NT208、NT201与其他家系的遗传距离则较远,分别构成独立的分支。

The genetic diversity and genetic relationship of 14 Nile tilapia Oreochromis niloticus families were analyzed using 14 microsatellite markers.The genetic analysis of 14 tilapia families showed that：Polymorphic bands could be amplified in 11 pairs of primers and the average number of alleles in each pair of primers was 8.36.14 tilapia families had a higher genetic polymorphism.The average polymorphism information contents,the average heterozygosities and the average effective allele numbers were0.499 3,0.558 3and 2.608 0,respectively.Pedigree analysis among the 14 Nile tilapia families showed that Family NT207 and NT213had the smallest genetic distance of 0.204 4,and Family NT208 and NT210had maximum genetic distance 0.760 9.The average Nei＇s genetic identity and average genetic distance among the 14 Nile tilapia families were 0.649 6and 0.440 2,respectively.UPGMA phylogenetic tree analysis showed that NT215,NT218,NT210 and NT211clustered to one branch,while NT214,NT203,NT206,NT207,NT213,NT217,NT209 and NT216clustered to another branch,while NT208 and NT201had far genetic distance with other families,each forming a separate branch.