Molecular studies of the Bionectriaceae using large subunit rDNA sequences

Holomorphic species of fifteen genera in the family Bionectriaceae, Hypocre ales, and related anamorph species were studied using nuclear large subunit rDNA sequences. Most elements of the Bionectriaceae are shown to form a mo nophyletic group closely related to representatives of two other families i n the Hypocreales, namely the Clavicipitaceae/Hypocreaceae, which is distin ct from the Nectriaceae. The genus Bionectria, represented by B. ochroleuca ccn and its anamorph, Clonostachys rosea, and B. cf. aureofulva, appears a s a monophyletic lineage that groups with three other species that may also belong to Bionectria. The Bionectria clade is distinct from a second major lineage that includes the perithecial genera Hydropisphaera, Nectriopsis, Ochronectria and Selinia, as well as two cleistothecial genera, Heleococcum and Roumegueriella. Within this lineage the cleistothecial genera, Heleoco ccum, represented by the nontype species, H. japonense, and the monospecifi c genus, Roumegueriella, group with the paraphyletic genus Hydropisphaera, including H. peziza, the type species, and H. erubescens. Another lineage i ncludes six cleistothecial genera, namely Bulbithecium, Emericellopsis, Hap sidospora, Leucosphaerina, Mycoarachis, and Nigrosabulum, most of which hav e Acremonium anamorphs. These genera cluster with the type of Acremonium, A . alternatum, and two anamorph genera, Geosmithia, and Stanjemonium. Both s pecies of Kallichroma, K tethys and K. glabrum, form a separate lineage wit hin the Bionectriaceae. Kallichroma is the first genus from marine habitats to be confirmed as a member of the Hypocreales. Although classified in the Bionectriaceae based on morphological evidence, species of the tropical ge nus Peethambara and their Didymostilbe anamorphs and the morphologically si milar anamorph genera, Albosynnema and Myrothecium, fall outside of any of the supported clades. These species form a paraphyletic group at the base t o the Hypocreaceae/Clavicipitaceae.