Discovery and epitypification of the sexual stage of Cadophora fallopiae (Pyrenopezizaceae, Helotiales) on Fallopia spp. in Japan

Discovery and epitypification of the sexual stage of Cadophora fallopiae (Pyrenopezizaceae, Helotiales) on Fallopia spp. in Japan

Hiyori Itagaki1* and Tsuyoshi Hosoya2

1Saimata Museum of Rivers, 39, Kosono, Yorii, Saitama, 369-1217, Japan

2 Department of Botany, National Museum of Nature and Science, 4-1-1 Amakubo, Tsukuba, Ibaraki 305-0005 Japan

*Email: hiyori_itagaki@river-museum.jp

The genus Cadophora was established as a dematiaceous asexual fungi featured by solitary phialides with distinct collarettes, and phylogenetically suggested to be the asexual stage of the family Pyrenopezizaceae (Helotiales, Ascomycetes). However, the sexual stage is unknown except for a few species. Cadophora fallopiae which occurs on the overwintered stems of Fallopia in Europe was described only for its conidiomatous asexual stage. In Japan, C. fallopiae-like conidiomata were discovered associated with apothecia of Pyrenopeziza sp. on the same substrate (stem of Fallopia spp). Therefore, we suspected the conspecificity of apothecia and conidiomata. Detailed comparison of morphology and ITS-5.8S sequences confirmed that this fungus is identical with C. fallopiae known in Europe, and the sexual stage was connected with its asexual stage for the first time. We also hypothesize the reason why sexual stage has not been discovered in Europe is that the lacking compatible mating type in Europe, based on genetic diversity of single ascosporous isolates derived from a single apothecium.