MORPHOLOGICAL AND MOLECULAR CHARACTERIZATION OF COLLETOTRICHUM-NYMPHAEAE AND COLLETOTRICHUM-NUPHARICOLA SP-NOV ON WATER-LILIES (NYMPHAEA AND NUPHAR)

Nine isolates of a Colletotrichum sp. collected in North America on ye llow water-lily (Nuphar luteum subsp. polysepalum) at five locations i n the Pacific Northwest (PNW) and one isolate from Nymphaeae odorata i n Rhode Island were compared to three isolates of C. nymphaeae occurri ng on Nymphaeae alba and Nuphar luteum in Europe. The appressoria of a ll North American isolates were significantly wider than those of C. n ymphaeae. Conidia of the nine PNW isolates were significantly wider th an those of both the Rhode Island isolate and C. nymphaeae isolates. A ll isolates were compared using random amplified polymorphic DNA (RAPD ) and restriction fragment length polymorphism of the ITS region (RFLP -ITS). Two distinct clusters were differentiated in the dendrogram bas ed on the RAPD analysis. The ten North American isolates formed one cl uster and the European isolates of C. nymphaeae formed a second cluste r. The separation of the North American isolates from the European iso lates was supported by distinct restriction digest phenotypes of the I TS region. Based on morphological and molecular characterization the N orth American fungus is proposed as a new species, C. nupharicola.