Helicobasidium longisporum
Helicobasidium longisporum is a species of fungus in the subdivision Pucciniomycotina. Basidiocarps are corticioid and are typically violet to purple. Microscopically they have auricularioid basidia. Helicobasidium longisporum is an opportunistic plant pathogen and is one of the causes of violet root rot of crops and other plants. DNA sequencing suggests that it is a complex of more than one species.
Taxonomy
Helicobasidium longisporum was first described from Uganda in 1917 by British mycologist Elsie Wakefield to accommodate a species similar to Helicobasidium purpureum but with elongated basidiospores. It was found parasitizing roots of cocoa. A similarly long-spored Japanese taxon was described as H. mompa f. macrosporum and a further long-spored species was subsequently described from Indonesia as H. compactum. All three were considered conspecific in a 1999 study.In 1955 Japanese mycologist Seiya Ito synonymized H. mompa f. macrosporum and H. compactum with a short-spored species, Helicobasidium mompa. As a result, at least some subsequent references to H. mompa refer to a long—spored species.
Initial molecular research, based on cladistic analysis of DNA sequences, indicates that at least two species occur in the H.longisporum complex, one in Europe and one in Africa and the Americas.