Poster Session: Systematics/ Evolution

579-P

The tropical tree pathogen, Rhizomorpha corynephora (Agaricales, Marasmiaceae), is transported by birds in Belize.
D. J. LODGE (1), M. C. Aime (2), K. K. Nakasone (3)
(1) USDA Forest Service, Luquillo, Puerto Rico, U.S.A.; (2) Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, U.S.A.; (3) USDA Forest Service, Madison, WI, U.S.A.

Rhizomorpha corynephora Kunze is an unusual pathogen of various trees and shrubs (including species of citrus) that was originally described from its vegetative state in wet forests of South America. The pathogenic phase has been observed in Surinam as a web blight that kills new shoots. The vegetative fungus usually appears as knobby-branched rhizomorphic structures of up to 50 cm in length that dangle from tree branches and initiate spread to neighboring plants. Recently, we found evidence that birds incorporate R. corynephora rhizomorphs into their nests, effecting longer-range transport. Reports of this pathogen as far north as Belize (in the Yucatan Peninsula) and evidence of avian transport are of potential concern for the southern USA. The sexual state has never been found, but DNA sequencing indicates R. corynephora is closely related to the genus Brunneocorticium in the Marasmiaceae (Agaricales). Vinnere et al showed in 2005 that a related species in the Campanella clade of the Marasmiaceae (named “sterile white basidiomycete 3034”) was pathogenic on grass in Australia. Other arboreal species in this clade should be investigated for pathogenicity, and R. corynephora should be monitored for evidence of northward movement.