Discovery and epitypification of the sexual stage of Cadophora fallopiae on Fallopia spp. in Japan.

Abstract

Abstract The genus Cadophora was established as a dematiaceous asexual fungi characterized 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 in a few species. Cadophora fallopiae which occurs on the overwintered stems of Fallopia in Europe, has only been described for its conidiomatous asexual stage. In Japan, C. fallopiae-like conidiomata were discovered associated with the apothecia of Pyrenopeziza sp. on the same substrate (the stem of Fallopia spp). Therefore, conspecificities of the apothecia and conidiomata were suspected. A detailed comparison of morphology and ITS-5.8S sequences confirmed that this fungus is identical to C. fallopiae known in Europe, and that the sexual stage was connected with its asexual stage for the first time. Based on the genetic diversity of single ascosporous isolates derived from a single apothecium, we hypothesized that the reason the sexual stage has not been discovered in Europe is the lack of a compatible mating type.