Abstract: By using random amplified polymorphic DNA (RAPD) technique, this paper analyzed the genetic diversity and differentiation of Dicranopteris pedata populations in the habitats with and without mine tailings Pb-Zn pollution. A total of 102 polymorphic loci were detected from 170 loci, and two RAPD-marked loci of the D. pedata population exposed to 20 years mine tailings Pb-Zn pollution were lost, which were presumed to be the gene segments sensitive to heavy metals. The population under mine tailings Pb-Zn pollution had slightly lower percentage of polymorphic loci, Shannon’s information index, and Nei gene diversity than un-polluted one (52.94%, 0.3059 and 0.2084；53.53%, 0.3196 and 0.2198, respectively), but its total genetic diversity was relatively high (70.59%, 0.3723 and 0.2472, respectively). There was a definite genetic differentiation between these two populations (Φ_st=0.1900, and G_st=0.1339), but the variation degree between the populations was far less than that within the populations, and the gene flow between the populations was high. Pb-Zn pollution had a deeper influence on the genetic differentiation of D. pedata, suggesting that this pollution might be a main driving force in the differentiation and micro-evolution of D. pedata in the process of adapting heavy metals pollution.

Key words: Alexandrium tamarense, Red tide, Nitrogen, Phosphorus, Specific growth rate