Evidence of reduction of gene flow between two cytotypes of Ranunculus silerifolius Lev. (Ranunculaceae) revealed with allozyme and intersimple sequence repeat polymorphisms

摘要

Gene flow between partially reproductively isolated Otaru and Matsuyama cytotypes of Ranunculus silerifolius was revealed using allozyme polymorphisms. Otaru and Matsuyama cytotypes in the parapatric population MIX were distinguishable critically by the different alleles of the Mdh-3 allozyme locus and the hybrids between both cytotypes shared both alleles of both cytotypes. The distribution pattern of the alleles of the Mdh-3 locus revealed that the gene flow did not occur between cytotypes within MIX. The value of gene flow between the two cytotypes within the parapatric population MIX (i.e. 0.503) was smaller than those between allopatric populations of the same cytotype (i.e. 2.550 or 1.700). The genetic distance between cytotypes within the parapatric population MIX was larger than those between the fat distant populations of the same cytotypes. Dendrograms based on the Nei's genetic distance using the variations of allozyme markers showed that Otaru and Matsuyama cytotypes formed clusters separately.