2015 Volume 61 Pages 31-37
Fifteen Pyricularia oryzae isolates from giant foxtail(Setaria faberii) were collected from a wide geographic range in Japan and subjected to DNA fingerprint analyses using transposable elements MGR586 and MAGGY as probes. The DNA fingerprint analyses revealed a complex lineage structure of the 15 isolates. When lineages were arbitrary defined as a group in which members shared greater than 70% similarities in their DNA fingerprint profiles, the 15 isolates could be sorted into 12 and 15 lineages by MGR586- and MAGGY-DNA fingerprint analyses, respectively. Three microgeographic populations of the giant foxtail pathogen, each of which contained 15 isolates collected from a 1㎡ area, were subjected to MGR586-DNA fingerprint analysis. In one of the three populations, the 15 isolates were sorted into two lineages with around 70% similarity. In contrast, all of the 15 isolates in the other two populations formed a single lineage with greater than 70% similarities. The giant foxtail pathogen was considered to possess a complex lineage structure, even at the microgeographic scale. However, the simple lineage structure observed in the two populations suggests that the complexity of lineage structure of the pathogen at the microgeographic scale varies depending on collection sites.