DESCRIPTION OF CALONECTRIA-RUMOHRAE SP. NOV. (ANAMORPH = CYLINDROCLADIUM-RUMOHRAE SP. NOV.)

Petiole lesions on leatherleaf fern [Rumohra adiantiformis (G. Forst.) Ching] from Panama were examined, and a fungus characteristic of the genus Cylindrocladium was isolated. Perithecia developed in culture on irradiated segments of carnation (Dianthus caryophyllus L.) leaves on water agar (CL/WA) and on irradiated stems of peanut (Arachis hypogae a L.) on water agar (PS/WA) within 3-4 weeks. Ascospores were exuded t hrough the ostiole and single ascopore cultures were established. All single ascopore cultures yielded the Cylindrocladium anamorph and prod uced perithecia on CL/WA and PS/WA. Comparison of morphological featur es of this fungus to those of Cylindrocladium spp, that bear the close st resemblance to it, C. heptaseptatum Sobers, Alfieri & Knauss and C. quinqueseptatum Boedijn & Reitsma, showed differences in morphology o f phialides, size and septation of conidia. Isoenzyme and RAPD (Random Amplified Polymorphic DNA) markers were also used to compare the fung us under study with four isolates of C. heptaseptatum and two of C. qu inqueseptatum. Based on 40 isoenzyme and on 206 RAPD markers detected for all isolates, three distinct groups-made up, respectively by C. he ptaseptatum, C. quinqueseptatum and by the fungus from Panama were fou nd. The morphological differences and the molecular data indicate that the fungus under study represents a new taxon. Calonectria rumohrae i s proposed for the binomial of the homothallic sexual state, and Cylin drocladium rumohrae for the corresponding asexual state.