Taxonomy and Morphology of Colletotrichum Species Pathogenic to Strawberry

The morphology of both conidia and setae of C. fragariae, C. gloeosporioides, and C. acutatum isolates from strawberry were compared and found to be distinct for each species. Strawberry leaf agar was an excellent medium for the production of morphologically uniform conidia typical of a species. Conidial shape was more useful than size in species determination. C. fragariae is not synonymous with C. gloeosporioides as proposed by von Arx. Isolates of C. gloeosporioides that did not form the teleomorph were reliably identified by conidial and setal morphology alone. Radial growth of C. acutatum from 21–30 C was significantly slower than that of C. fragariae and C. gloeosporioides. At 33 C only isolates of C. gloeosporioides that did not produce the teleomorph grew well. Isolates of C. acutatum that formed a red pigment in culture are discussed.