长江下游铜鱼遗传多样性的随机扩增多态DNA(RAPD)分析

用随机扩增多态DNA(RAPD)技术对长江下游铜鱼(Coreius heterodon)20个个体的遗传多样性进行了检测，从4O个随机引物中筛选出19个对每个铜鱼的DNA进行扩增。结果表明，19个引物共检测到95条清晰且重复性好的条带，分子量在100～1500 bp之间，其中多态位点为30个，占31.58%；群体的Shannon多样性值为0.1940；个体间最大遗传距离为0.0976，最小遗传距离为0.0003。通过与其他鱼类的遗传多样性的研究结果比较可初步判断，长江下游铜鱼群体的遗传多样性较低。由于没有以前的遗传多样性分析资料，因此不能评判过度捕捞和自然环境的破坏等因素对铜鱼遗传多样性的影响程度。

RAPD analysis on genetic diversity of Coreius heterodon in the lower reach of the Yangtze River

Random amplified polymorphic DNA (RAPD)technique was employed to detect the DNA polymorphism in 20 individuals of Coreius heterodon in the lower reach of the Yangtze River． 19 arbitrary primers were used and 90 repeatable RAPD bands were generated．The length of the fragments varied from 100bp to 1500 bp．The percentage of polymorphic fragments was 31.58% ，while the index of Shannon diversity was 0.1940．The genetic distance between individuals was from 0.0003 to 0.0976．Comparing the genetic diversity of Coreius heterodon with that of other fishes，the experiment revealed that the genetic diversity of Coreius heterodon in the lower reach of the Yangtze River was a little lower． Owing to lack of historic data，we could not judge the effect on its genetic diversity caused by excessive fishing and environment destruction according to the results of this research．