2006 年 12 巻 p. 365-370
We investigated genetic variation and spatial structure of the loach Misgurnus anguillicaudatus population in drainage canals of Yatsu paddy field, Chiba Prefecture using microsatellite DNA markers. Populations in seven drainage canals in the Shitada-gawa River Basin were examined in this study. Population samples of 24 individuals were collected in each canal (a total of 167 individuals) in September 2004. Genotypes of alleles for three microsatellite loci, Mac 23, 43 and 48 for each individual were measured with PCR and electrophoresis techniques. Values of heterozygosity as an index of genetic variation, of populations ranged from 0.41 to 0.57 in all canals, and the null hypotheses of the Hardy-Weinberg equilibrium for most populations were not rejected at the 0.05 level of significance. Results of cluster analyses for Fst as an index of spatial genetic structure, among canals suggested that these populations could be divided into three groups, composed of upstream, central and downstream populations.
