长江中游鲢鱼天然种群的生化遗传结构及变异

采用淀粉或聚丙烯酰胺凝胶电泳方法分析长江中游鲢鱼天然种群11种同工酶约31个基因座位的遗传变异性。在可用于种群遗传结构分析的27个座位中，有4个座位（Ldh－C，idhp－A，Est－1－2）具有多态性。该种群的多态座位比例为14．8％，平均杂合度为0．0451。比较结果表明，鲢鱼天然种群的多态座位比例与人工繁殖种群相似。我们认为，鱼类人工繁殖种群遗传变异性的降低在很大程度上取决于人工繁殖过程中的某些不合理因素，人为地避免或限制这些因素将有利于保持鱼类人工繁殖种群的遗传变异性。

BIOCHEMICAL GENETIC STRUCTURE AND VARIATION IN A NATURAL POPULATION OF SILVER CARP FROM THE MIDDLE REACHES OF THE YANGTZE RIVER

Using starch and polyacrylamide gel electrophoresis, we analyzed the Oariants of 11 isozymes encoded by 31 presumphve loci in a natural silver carp population from the middle reaches of the Yangtze River. Among the 27 loci usable for genetic populahon analysis, four (Ldh-C, Idhp-A, Est-1, -2) were polmorphic. The mean propotion of polymorphic loci and the average heterozygosity per locus in the mentioned population wer 14.8% and 0.0451, respectively. Comparative result showed that silver carp hatehery and natural populations had a similar mean proportion of polymorphic loci. It was proposed that the reduction of genetic variability in fish hatchery populations was resulted from some unreasonable factors in propagation process to a great extent and avoiding or minimizing these factors intentionally would be useful for maximzing the genetic variability in hatchery populations of cultoral fish species.