利用微卫星分析吉富罗非鱼群体的遗传多样性

Genetic diversity analysis amongst GIFT strains of Oreochromis niloticus using microsatellites

【目的】为吉富罗非鱼种质资源的保护、评价以及育种提供理论依据。【方法】利用微卫星分子标记技术分析广东省化州光辉养殖场有限公司新选育的吉富罗非鱼第16代群体(F16)的遗传多样性。【结果】筛选出的8个微卫星位点在吉富罗非鱼群体中共检测到44个等位基因,各位点的等位基因数为3～8个,平均5.5个,而平均有效等位基因数为4.77个。等位基因片段长度为118～256bp,平均观测杂合度(H)o为0.8058,平均期望杂合度(H)e为0.7292,群体内个体间在不同位点的平均基因多样性为0.7044,群体内平均固定系数(FIS)为-0.2261,平均多态信息含量(PIC)为0.7044。所检测的8个位点均为高度多态位点(PIC>0.5000)。【结论】研究所选用的吉富罗非鱼群体的多态信息含量较丰富,具有较高的遗传异质性和较大的选育空间,可作为下一步选育工作的基础选育群体。

[Objective]The experiment was conducted to assess the genetic diversity of a new selected GIFT strain of Oreochromis niloticus in order to evaluate and preserve this strain as a germplasm resource. [Method]Genetic diversity of the newly bred F16 population of GIFT strain Nile tilapia obtained from Guanghui Farm Limited Company, Huangzhou （Guangdong, China） was analyzed using microsatellite markers. [Result]A total of 44 alleles were detected in the population by using 8 microsatellite primers, and the number of allele at each locus ranged from 3 to 8 with an average of 5.5. The mean number of effective allele was 4.77. The size of allele fragment ranged from 118 to 256 bp. The average observed heterozygosity was 0.8058 and the average expected heterozygosity was 0.7292. The average gene diversity between individuals within populations was 0.7044, and the mean fixation index coefficient of population was -0.2261. The average polymorphism information content （PIC） was 0.7044. All of the 8 detected loci were in a high polymorphism degree （PIC0.5000）. [Conclusion]There was rich polymorphism information content and wide genetic diversity in the population of GIFT strain of Oreochromis niloticus. This selected GIFT strain population still has wide selection potential and can be used as a base population for further breeding.