结合线粒体D-loop序列和SSR标记对宝石鲈养殖群体遗传多样性的分析

Mitochondrial D-loop sequences and simple sequence repeat markers combination analysis of genetic diversity in reared Scortum barcoo populations

采用线粒体D-loop序列及SSR标记分析广东4个宝石鲈(Scortum barcoo)养殖群体的遗传多样性。D-loop序列分析显示,长度为598bp的D-loop片段上有14个多态性位点,共定义8个单倍型。4个群体单倍型多样性指数、核苷酸多样性指数分别为0.0000~0.5435、0.00000~0.00176,表明4个群体遗传多样性水平均较低。利用11个SSR位点分析显示,4个群体期望杂合度(He)=0.396~0.516、PIC=0.320~0.420,说明各群体遗传多样性处于中低水平。虽然二种方法获得的遗传分化指数FST上存在差异,分别为0.4035(D-loop)和0.0445(SSR),但二种分析结果均显示4个广东群体的遗传多样性较低、亲缘关系较近,因此有必要引进原种以丰富国内养殖群体的遗传多样性。

Mitochondrial D-loop sequences and simple sequence repeat ( SSR) markers were used in this study to analyze the genetic diversity in 4 different reared Scortum barcoo populations in Guangdong. D-loop sequences analysis showed that the 598 bp long D-loop fragment contained 14 polymorphic loci and a total of 8 defined haplotypes. The haplotype diversity index and nucleotide diversity index of the 4 populations were ranged from 0.000 0 to 0.543 5 and from 0.000 00 to 0.001 76, respectively, which showed that the genetic diversity levels of the 4 populations were low. Analysis of 11 SSR loci showed that the expected heterozygosity ( H e ) of the 4 different populations were ranged from 0.396 to 0.516 and polymorphism information content ( PIC ) were ranged from 0.320 to 0.420, which suggested that the genetic diversity between the various populations were at moderate to low level. Although there were differences in the genetic differentiation coefficient ( F ST ) obtained via the two different methods ( 0.403 5 for D-loop and 0.044 5 for SSR), the results of these 2 methods showed that the 4 Guangdong populations had low genetic diversity and close phylogenetic relationships. Therefore, there is a need to introduce the original species to enrich the genetic diversity of the reared populations in China.