Internal transcribed spacer haplotype diversity and their geographical distribution in Dasyscyphella longistipitata (Hyaloscyphaceae, Helotiales) occurring on Fagus crenata cupules in Japan

Phylogeographic analysis of Dasyscyphella longistipitata (Hyaloscyphaceae, Helotiales), which occurs on decaying Fagus crenata cupules, was carried out. The ITS-5.8S regions of the 120 isolates from 12 sites in areas across Japan revealed 38 haplotypes, the majority of which comprised the haplotype designated H12 (42.5%). H12 was found in isolates from all sites, followed by H28 and H10, which were detected in isolates from 10 and 7 sites, respectively. Thirty-two haplotypes were obtained in single isolates. In the haplotype network, H12 was the root, and it formed interior clades with H28 and H10. Genetic diversity was higher in northern and southern Japan, but genetic distance was not correlated with geographical distance, nor with the phylogenetic clades of F. crenata. Therefore, it was concluded that D. longistipitata forms a genetic continuum that covers all of the areas in which it is distributed in Japan, with variations being generated in local populations from the major haplotypes.