Identity of Guignardia sp. inhabiting ericaceous plants

An ascomycete belonging to the genus Guignardia with a Phyllosticta anamorph was frequently isolated from living leaves of several ericaceous plants. Ecological study on assemblages of endophytes suggested that this fungus is a dominant endophytic fungus of ericaceous plants. The Phyllosticta anamorph was morphologically similar to Phyllosticta capitalensis P. Henn., which can be a pathogen of orchids. An authentic culture of P. capitalensis IFO 32914 (= CBS 226.77) produced an ascigerous stage on potato dextrose agar, the morphology of which was identical to the Guignardia sp. from ericaceous plants. Sequence data of the internal transcribed spacer regions of ribosomal DNA (ITS1 and ITS2, including 5.8S rDNA) supported the identity of the present fungus and P. capitalensis. Consequently, we describe this endophytic ascomycete found from ericaceous plants as Guignardia endophyllicola sp.nov., which has P. capitalensis as an anamorph. Previously known as a pathogen of orchids, the fungus was revealed to exist widely as an endophyte within ericaceous plants.Key words: endophytic fungus, Ericaceae, Guignardia endophyllicola, pathogenic fungus, Phyllosticta capitalensis, Orchidaceae.