鲂属团头鲂、三角鲂及广东鲂种间遗传关系及种内遗传差异

采用形态判别、同工酶分析和RAPD分析相结合的方法，从3个层次研究分析了鲂属团头鲂、三角鲂和广东鲂的种间亲缘关系和种内遗传差异。结果表明：（1）3种鲂在形态可数性状上差异不显著，而可量性状与框架分析揭示团头鲂与三角鲂亲缘关系较近，它们同广东鲂差异较大；（2）团头鲂和三角鲂均具有MDH同工酶的s-Mdh-D位点，而广东鲂未见，引物S11扩增的结果在3种鲂间均显示种的特异性，这些同工酶谱带和DNA扩增带可作为3种鲂的种间分子标记；（3）3种鲂种间亲缘关系在三个研究层面上相互吻合：即广东鲂和头鲂、三角鲂差异较大，亲缘关系较远，而三角鲂和团头鲂之间差异小，亲缘关系较近；（4）同工酶和RAPD分析揭示，三角鲂种内遗传多样性显著地高于广东鲂和团头鲂。

INTERSPECIFIC PHYLOGENESIS AND INTRASPECIFIC GENETIC DIFFERENCES OF GENUS MEGALOBRAMA: BLUNTNOSE BLACK BREAM (M.AMBLYCEPHALA), GUANGDONG BLACK BREAM (M.HOFFMANNI) AND BLACK BREAM (M.TERMINALIS)

We studied interspecific phylogenetic relationships and intraspecific genetic variations of three species in genus Megalobrama,M.amblycephala, M.terminalis and M.hoffmanni by morphologic discrimination analysis, enzyme analysis and RAPD analysis. The results showed that: (1) there were no significant differences on meristic characters of the three breams, but measurable parameters ratio and truss framwork of the three species presented a close relationships between M.amblycephala and M. terminalis , and obvious differences between them and M.hoffmanni ;(2) the band s Mdh D of enzyme MDH existed in M.amblycephala and M. terminalis , but not in M.hoffmanni . The RAPD primer S11 could amplify species specific bands in each of three species. These enzyme band and PCR amplified bands all could be used as interspecific molecular markers;(3) the same conclusion could be made on interspecific relationships of the three species by morphologic discrimination analysis, enzyme analysis and RAPD analysis, namely, M.hoffmanni had significant differences with M.amblycephala and M.terminalis, and there were small differences between M.amblycephala and M.terminalis ;(4) allozyme and RAPD analysis revealed that the genetic diversity within species of M.terminalis was significantly higher than that of M.amblycephala and M.hoffmanni.