Phylogenetic relationships of five uncommon species of Lasiosphaeria and three new species in the Helminthosphaeriaceae (Sordariomycetes)

摘要

In an ongoing effort to monograph the genus Lasiosphaeria, it is desirable to obtain estimates of the phylogenetic relationships for five uncommon species, L. coacta, L. munkii, L. punctata, L. sphagnorum and L. stuppea. Three additional species previously placed in Lasiosphaeria, Echinosphaeria canescens, Hilberina caudata and Ruzenia spermoides, also were included in this study as well as three undescribed species. These species were believed to have relations elsewhere based on various ambiguous morphological characters, so an independent dataset from one or more genes was used to resolve their phylogenetic affinities. Sequences from the nuclear ribosomal 28S large subunit (LSU) and beta-tubulin genes were generated for these taxa. Maximum likelihood and Bayesian analyses indicated these taxa form a well supported monophyletic group with members of the Helminthosphaeriaceae and therefore, should be transferred out of Lasiosphaeria. Except for Helminthosphaeria gibberosa, Hilberina elegans, Ruzenia spermoides and Synaptospora plumbea, all taxa within this clade possess ascomata with distinct thick-walled setae. Based on a combination of morphological and molecular data, Helminthosphaeria tomaculum, Helminthosphaeria triseptata and Hilberina robusta are described as new and four new combinations are proposed: Helminthosphaeria ludens, Hal. stuppea, Hilberina punctata and H. sphagnorum. Ten new combinations are proposed based on morphological data: Echinosphaeria heterostoma, Helminthosphaeria flavocompta, Hel. gibberosa, Hal. heterotricha, Hilberina breviseta, H. elegans, H. foliicola, H. meznaensis, H. moseri and H. rhynchos- to belong in the family. Illustrations are provided for most Helminthosphaeriaceae taxa seen in this study.