Two new species of Diaporthe (Diaporthaceae, Diaporthales) associated with tree cankers in the Netherlands.

Diaporthe (Diaporthaceae, Diaporthales) is a common fungal genus inhabiting plant tissues as endophytes, pathogens and saprobes. Some species are reported from tree branches associated with canker diseases. In the present study, Diaporthe samples were collected from Alnusglutinosa, Fraxinusexcelsior and Quercusrobur in Utrecht, the Netherlands. They were identified to species based on a polyphasic approach including morphology, pure culture characters, and phylogenetic analyses of a combined matrix of partial ITS, cal, his3, tef1 and tub2 gene regions. As a result, four species (viz.  Diaporthepseudoalnea sp. nov. from Alnusglutinosa, Diaporthesilvicola sp. nov. from Fraxinusexcelsior, D.foeniculacea and D.rudis from Quercusrobur) were revealed from tree branches in the Netherlands. Diaporthepseudoalnea differs from D.eres (syn. D.alnea) by its longer conidiophores. Diaporthesilvicola is distinguished from D.fraxinicola and D.fraxini-angustifoliae by larger alpha conidia.