Ophiostoma species (Ophiostomatales, Ascomycota), including two new taxa on eucalypts in Australia

02 Aug 2011

The genus Ophiostoma accommodates ascomycetes in the order Ophiostomatales, some of which are important pathogens of trees. Although these fungi are well known in the northern hemisphere, very little is known regarding their occurrence or importance in Australia. The aim of the present study was to collect Ophiostoma spp. infecting wounds on Eucalyptus spp. in Australia, where most of these trees are native. Collections were made in three states of Australia and the isolates were identified using morphological and multigene-sequence comparisons. Of the 76 isolates collected, two previously unknown species of Ophiostoma were found and these are described here as O. tasmaniense sp. nov. and O. undulatum sp. nov. In addition, O. quercus (Georgev.) Nannf. and O. tsotsi Grobbelaar, Z.W.de Beer & M.J.Wingf. are reported for the first time from eucalypts in Australia and the distribution of Pesotum australiae Kamgan Nkuekam, Jacobs & Wingfield is expanded to include eucalypts in Tasmania. In pathogenicity tests, very small lesions were observed in both the bark and xylem of E. grandis (Hill) Maiden trees, suggesting that none of the collected species is a pathogen of Eucalyptus spp.