Neotypification of Dothistroma septosporum and epitypification of D. pini, causal agents of Dothistroma needle blight of pine

摘要

Dothistroma needle blight (DNB) is one of the most devastating needle diseases on Pinus spp. worldwide. Ever since the description of the causal agent of the disease in Europe in 1911 as Cytosporina septospora, and independently in the USA in 1941 as Dothistroma pini, there has been considerable taxonomic discordance regarding the name of the pathogen used in literature. This was compounded both by the proposal of different varieties of the pathogen based on differences in spore size and the application of dual nomenclature where three names, Scirrhia pini, Eruptio pini and Mycosphaerella pini, were used to describe the sexual morph of the fungus. More recent studies using sequence--based methods revealed that DNB can be caused by either one of two distinct species, that is D. septosporum and D. pini. These important species have not been adequately typified, and this perpetuates lack of stability for their names. In this study, these names are fixed to reference sequences linked to living cultures representing type specimens. To achieve this goal, we designate an epitype for D. pini and a neotype for D. septosporum. The known polymorphism in the ITS region, the barcoding gene for these fungi, is characterized and a complete taxonomic history is provided for the genus Dothistroma.