Taxonomy of Ophiostoma radiaticola sp. nov. (Ophiostomatales, Ascomycetes), the teleomorph of Pesotum pini, isolated from logs of Pinus radiata

Abstract

A new Ophiostoma species causing sapstain was isolated from Pinus radiata logs grown and stored in New Zealand, and imported from New Zealand to Korea. Ophiostoma radiaticola produces dark ascomata with long necks, lacks ostiolar hyphae and has hyaline reniform ascospores with a hat-shaped sheath. The fungus has mononematous Leptographium-like conidiophores that intergrade with synnematous Pesotum-like conidiophores, the latter previously described under the anamorph name Pesotum pini Mating tests on pine sapwood wafers demonstrated that O. radiaticola is a heterothallic species with two mating types. Phylogenetic analyses of aligned ITS 2/partial LSU rDNA, partial β-tubulin and partial actin DNA sequences demonstrate that O. radiaticola is a phylogenetically distinct species most closely related to O. cainii and O. galeiformix, with which it shares many morphological characters. It is also more closely related to Ophiostoma species with Leptographium anamorphs than to species of the O. piceae and O. ulmi complexes, the best-known groups of species with Pesotum anamorphs.