两个镜鲤半同胞家系的遗传多样性及经济性状分析

在两个镜鲤半同胞家系中，各随机选取47尾作为实验鱼，测量体重、体长、全长等数量性状，利用24个微卫星分子标记对其进行遗传检测，共检测到57个等位基因，每个基因座的等位基因数为1－6个不等，平均等位基因3.21个，片段长度在134－371bp之间，有效等位基因数Ne为1.00－2.89， 平均观察杂合度Ho为0.00－0.83，平均期望杂合度He为0.00－0.66，平均多态信息含量PIC为0.00－0.58。结果表明：2个家系的遗传多样性处于中度水平，但连锁不平衡分析表明这两个家系在较大的选择压力下，已严重偏离Hardy-Wenberg平衡。利用SPSS程序下的GLM过程对24个微卫星位点与主要经济性状的相关性进行分析，结果发现：HLJ519，HLJ848、HLJ855、HLJE8 4个微卫星位点对镜鲤体重显著影响(p<0.05)，其中，位点HLJ519，HLJ848、HLJ855还对体长和全长存在显著影响(p<0.05)。对这些位点基因型所对应的表型均值进行了多重比较，找到了一些对主要经济性状有利的基因型。

Analysis of genetic diversity and economic traits in two mirror carp semi-sib families

Mirror carp (Cyprinus carpio L.) is one of the most important traditional domestic freshwater aquaculture fish in China. The seeding of mirror carp for aquaculture has come from the Heilongjiang River because germplasm resource of mirror carp is superior to those from other rivers and lakes. But advanced biological characteristic for aquaculture germplasm of mirror carp was obviously decreased during past years after multigene rations artificial propagation. The growth became slowly and the ability of antidisease reduced. Therefore, it is necessary to analyze and study genetic diversity and correlation analysis of microsatellite DNA markers with economic characters in mirror carp. In the present study, the genetic diversity and population structure of mirror carp from Heilongjiang River system were investigated using microsatellite DNA markers. The genetic examination on 24 microsatellite markers and combined quantity characters such as the body weight, body length and full length was carried out among the random samples in two semi-sib families of mirror carp, a total of 57 different alleles were found and the number in each locus ranged from 1 to 6. The average number of alleles was 3.21. The DNA fragment lengths were from 134 bp to 371 bp. In the two semi-sib families, the number of mean valid alleles (Ne) was 1.00 to 2.89, the value of average observed (Ho) and expected heterozygosity (He) ranged from 0.00 to 0.83 and 0.00 to 0.66, respectively, and the mean PIC was 0.00 to 0.58. The result showed that the level of genetic variability was moderate. Chi-square test was used to analyze the genotypes based on Hardy-Weinberg equilibrium, the P value denoted that the 2 families deviated equilibrium partially. A GLM procedure was used to analyze the effects of these 24 microsatellites on economic characters. Results uncovered that there existed 4 loci, HLJ519, HLJ848, HLJ855 and HLJE8, which had a significant impact on body weight (p<0.05). The HLJ519, HLJ848 and HLJ855 loci correlated with length and full length character significantly (p<0.05). Genotypes of that favorably affect economic characters were determined. Multiple comparisons of economic characters among microsatellite loci genotypes showed that allele 281 in locus HLJ519, allele 279 in locus HLJ848, allele 209 in locus HLJ855 and allele 189 in locus HLJE8 closely linked to the major gene related to body weight, body size and whole size of economic characters in mirror carp.