CHARACTERISTICS OF COLLETOTRICHUM FROM PEACH, APPLE, PECAN, AND OTHERHOSTS

Seventy-two Colletotrichum isolates from peach, apple, pecan, and othe r hosts were examined morphologically and tested in vitro for benomyl sensitivity and for polymorphisms in the ribosomal 188 and 28S transcr iptional unit. In general, the isolates separated into pink and gray c olony types. Each type was isolated from peach, apple, and pecan. Rega rdless of host origin, pink isolates produced pink to pinkish-orange c olonies on potato-dextrose agar (PDA), grew on benomyl-amended medium, produced mostly fusiform conidia, and had similar restriction fragmen t length polymorphism (RFLP) patterns. Gray isolates produced gray col onies on PDA, grew slightly or not at all on benomyl-amended medium, h ad conidia with rounded ends, and had similar RFLP patterns that were distinct from pink isolates. Symptoms on detached peach fruit followin g inoculation with gray and pink isolates were not visually distinguis hable. The two types corresponded to C. acutatum (pink isolates) and C . gloeosporioides (gray isolates), respectively. We concluded that C. acutatum and C. gloeosporioides are separate species and are found on peach, apple, and pecan.