华南鲤选育群体不同世代遗传多样性与遗传结构的微卫星分析

GENETIC DIVERSITY AND GENETIC STRUCTURE ANALYSIS OF DIFFERENT SELECTIVE BREEDING GENERATIONS IN CYPRINUS CARPIO RUBROFUSCUS USING MICROSATELLITE MARKERS

  • 摘要: 为了解人工选育对华南鲤(Cyprinus carpio rubrofuscus)选育群体遗传结构的影响, 采用微卫星技术分析了华南鲤4个连续选育世代(F1、F2、F3和F4)的遗传多样性和遗传结构。结果显示:在4个选育群体中, 16对微卫星引物共扩增得到99个等位基因, 每个微卫星座位检测到的等位基因数为3—10个, 平均为6.1875个。随着人工连续选育的进行, F1到F4的平均等位基因数(Na)从5.6875下降到4.6755, 平均观测杂合度(Ho)从0.7943下降到0.7135, 平均多态信息含量(PIC)从0.6577下降到0.5834。F1与其后各代的遗传距离逐代增加(从0.1486上升到0.2181), 遗传相似系数逐代减小(从0.8619下降到0.8041), 而相邻世代间的遗传分化指数(Fst)逐代变小(F1与F2为0.062, F2与F3为0.058, F3与F4则为0.051), 遗传相似性逐步升高。世代间Fst值配对比较结果显示4个世代间的遗传分化处于中等水平, 表明人工选育已对华南鲤选育群体的遗传结构产生了影响。实验结果表明, 华南鲤经过4代选育后, 虽然遗传杂合度和遗传多样性存在下降的现象, 但遗传多样性水平依然较高, 还具有进一步选育的潜力。研究结果为下一步制定华南鲤新品种选育计划提供基础遗传数据。

     

    Abstract: The present study aimed to examine the genetic diversity and genetic structure of the successive selective breeding populations of Cyprinus carpio rubrofuscus from F1 to F4 generations by using 16 microsatellite markers. The results showed that 99 alleles were detected among 16 polymorphic microsatellite loci. The number of alleles detected on each locus varied from 3 to 10, and the average number of alleles was 6.1875. From F1 to F4 generations, the average number of alleles for 16 microsatellite markers decreased from 5.6875 to 4.6755, the average of heterozygosity ranged from 0.7943 to 0.7135, and the average of polymorphism information content (PIC) reduced from 0.6577 to 0.5834, respectively. The genetic distance between F1 and its descendant generations (F2-F4) increased from 0.1486 to 0.2181, while the genetic identity decreased from 0.8619 to 0.8041. The values of genetic differentiation index (Fst) between the adjacent generations decreased (0.062 between F1-F2; 0.058 between F2-F3; and 0.051 between F3-F4), whereas the values of genetic identity increased. Pairwise values of Fst ranged from 0.05 to 0.15, reflecting that the selective breeding populations contained moderate genetic differentiation among four generations and the genetic structure has been varied from one generation to the next one through selective breeding. This study suggested that the selective breeding was an efficient approach, and there was a decrease in genetic heterozygosity and genetic diversity, while high genetic diversity and genetic potential were maintained in the selective breeding populations, indicating that there is a great potential for future selections of Cyprinus carpio rubrofuscus through selective breeding. Our study provides precious information for genetically breeding in Cyprinus carpio rubrofuscus as well.

     

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