Anamorphs of the Bolbitiaceae (Basidiomycota, Agaricales)

Abstract

We describe and illustrate thallic conidiogenesis in 14 species of the Bolbitiaceae sensu Singer studied in culture. Conidiogenesis of 12 species is shown for the first time. Bolbitius vitellinus and the investigated species of Conocybe (C. albipes, C. appendiculata, C. magnicapitata, C. semiglobata, C. subovalis, C. subpubescens, C. sulcatipes and C. teneroides) possessed a similar mode of conidiogenesis. Species of both genera formed mostly coiled conidiogenous hyphae arising sympodially from differentiated conidiophores. The anamorphs of the Agrocybe species were not uniform and predominantly differed from those of Conocybe and Bolbitius. The conidia of Agrocybe dura, A. firma and A. praecox developed by the simple fragmentation of normally branched hyphae. Sympodially proliferating conidiophores occurred in Agrocybe arvalis and A. aegerita. Secretory cells of different size and shape were found in Agrocybe and in Conocybe. Our results corroborate a close phylogenetic relationship between Bolbitius and Conocybe as well as the polyphyly of the Bolbitiaceae as currently treated, which is consistent with recent molecular phylogenetic studies. Consequently we emend the family concept based on anamorphic characters.

• Agrocybe
• basidiomycetes
• Bolbitius
• conidia
• conidiogenesis
• Conocybe
• culture characters
• secretory cells

We thank Heinrich Dörfelt and Walter Gams for helpful discussions of diverse problems concerning anamorphs and Bayer HealthCare for financially supporting this study. We are also grateful to Cambridge University Press for the kind permission to reproduce parts of Fig. 2C, which originally appeared in Walther et al (2005).