江黄颡(♀)和乌苏里拟鲿(♂)及其杂交子代遗传变异的RAPD分析

RAPD analysis of genetic variation between Pelteobagrus vachelli(♀) and Pseudobagrus ussuriensis(♂) and their hybrids

利用RAPD分子标记分析了江黄颡（♀）和乌苏里拟鲿（♂）及其杂交子代3个群体的遗传结构。18个RAPD随机引物对每个群体8尾鱼的基因组DNA进行扩增，共获得106个条带清晰且重复性较好的RAPD标记，片段大小在200～2000bp之间，江黄颡（♀）和乌苏里拟鲿（♂）及其杂交子代3个群体的多态位点比例分别为17．92％、18．87％和25．47％，平均遗传相似系数分别为0．9408、0．9368和0．9280，平均遗传距离分别为0．0592、0．0632和0．0720，平均Nei’s基因多样性指数（H）分别为0．0754、0．0738和0．1036，平均Shannon信息指数（I）分别为0．1087、0．1081和0．1501；亲缘关系树状图显示杂交子代与母本遗传距离较近，而与父本遗传距离较远。结果分析表明：杂交子代继承了双亲的优良性状，但从母本中继承的遗传物质稍多于父本；杂交子代群体内的遗传多样性高于两亲本群体，杂交一代基因杂合性增强，表现出一定的杂种优势。

Genetic structure of three populations （Pelteobagrus vachelli （ ♀ ） and Pseudobagrus ussuriensis （ ♂ ） and their hybrids） was analyzed by Random Amplified Polymorphic DNA （RAPD） molecular marker. The genomic DNA of P. vachelli（ ♀ ）, P. ussuriensis （ ♂ ） and their offspring were examined using 18 kinds of random primers. The results showed that 106 kinds of random markers were detected; they had clear band and good repeatability, and the segment sizes were arranged from 200 bp to 2 000 bp. The polymorphic loci proportion of P. vachelli（ ♀ ）, P. ussuriensis （ ♂ ） and their hybrids were 17.92%, 18.87% and 25.47%, the mean genetic similarity coefficient was 0. 940 8, 0. 936 8 and 0. 928 0, the mean genetic distance was 0.0592, 0.063 2 and 0.072 0, the mean Nei＇s gene diversity index （H） was 0.075 4, 0.073 8 and 0. 103 6, and the mean Shannon information index （I） was 0. 108 7, 0. 108 1 and 0. 150 1. The dendrogram of phylogenetic relationship demonstrated that there is the closest phylogenetic relationship between hybrids and P. vachelli （ ♀ ） population, and slightly farther compared to P. ussuriensis （ ♂ ）. All the results indicated that hybrid generation inherited good characters of their parents, but genetic material inheriting of female parent was a bit more than male parents. The genetic diversity of hybrids was higher than their parents. The hybrid generation had enhanced gene heterozygosity and performed a certain heterosis.