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利用罗非鱼第二代遗传连锁图谱中微卫星标记对尼罗罗非鱼(Oreochromis niloticus)(♀)×萨罗罗非鱼(Sarotherodon melanotheron)(♂)杂交后代F_2、F_3群体遗传特征进行了初步比较分析。结果显示,28对引物中有22对引物能有效扩增,未观察到杂交后代F_2、F_3中有多倍体个体现象。筛选出7个在尼萨罗非鱼杂交后代F_2、F_3群体中存在差异的位点。杂交F_2群体平均等位基因(Na)为2.71,平均多态信息含量(PIC)为0.466,平均观测杂合度(Ho)为0.632;杂交F_3群体平均Na为2.14,平均PIC为0.370,平均Ho为0.432,杂交F_3遗传杂合性较杂交F_2降低。F_2自繁F_3过程中,F_3群体4个位点的等位基因与F_2完全相同,3个位点的等位基因少于F_2,且F_3群体在2个位点出现完全纯合,杂交F_3群体位点等位基因呈现纯合趋势。研究结果为尼萨罗非鱼杂交世代遗传变异与杂交利用积累基础资料。
The genetic characteristics of F_2 and F_3 populations of hybrids of Oreochromis niloticus (♀) × Sarotherodon melanotheron (♂) were analyzed by microsatellite markers in the second generation genetic linkage map of tilapia Preliminary comparative analysis. The results showed that 22 of 28 pairs of primers could effectively amplify, and no polyploid individuals in F_2 and F_3 of hybrid progenies were observed. The results showed that there were differences among F_2 and F_3 populations in the cross of Nile tilapia. The average allele (Na) of hybrid F_2 population was 2.71, PIC was 0.466 and the average observed heterozygosity (Ho) was 0.632. The average Na of hybrid F 3 population was 2.14 and the average PIC was 0.370. The average Ho was 0.432, the heterozygosity of hybrid F_3 was lower than that of hybrid F_2. In F 2 autotrophic F_3, the alleles of F_3 were the same as that of F_2, the alleles at 3 loci were less than that of F_2, and the F_3 population was completely homozygous at 2 loci. The hybrid F_3 population Site alleles showed a homozygous trend. The results provide the basic data for the genetic variation and hybridization utilization of the hybrids of Nile tilapia.