The first ITS phylogeny of the genus Cantharocybe (Agaricales, Hygrophoraceae) with a new record of C. virosa from Bangladesh

Abstract

This is the first internal transcribed spacer (ITS) phylogeny of the enigmatic genus Cantharocybe and includes ITS sequences from two out of the three holotype collections. Two species are reported from the Americas and only a single species from Asia. Additionally, a collection of Cantharocybe virosa collected from tropical Bangladesh was included in this study. This species is a new record for Bangladesh, and is characterized by its tawny gray or grayish brown pileus and stipe surface, smooth ellipsoid basidiospores, elongated necked lecythiform cystidia, a trichoderm pileipellis, and abundant clamp connections. Molecular phylogenetic analysis using ITS, and combined analyses of ITS with the large subunit of nuclear ribosomal RNA (nrLSU) showed that the collection from Bangladesh is conspecific with the Indian C. virosa. A large, previously unknown intron was found in the ITS of C. brunneovelutina and C. virosa, while the C. gruberi sequence was found to be truncated where the intron would have been inserted. The intron was not identical between Cantharocybe species, and may be phylogenetically informative. Morphological description, color photographs and line drawings are provided for Bangladesh collection C. virosa. A key to the genus Cantharocybe is provided.