COMPARATIVE-STUDIES OF CRYPTOSPORIOPSIS-CURVISPORA AND C-PERENNANS .1. MORPHOLOGY AND PATHOGENIC BEHAVIOR

Macroconidia of Cryptosporiopsis curvispora, cause of apple anthracnos e, consistently displayed high curvature while those of C. perennans, cause of perennial canker, displayed low curvature when representative isolates of both species were separately and simultaneously inoculate d into apple branches. Highly curved macroconidia were occasionally pr oduced on potato dextrose agar by the former species but never by the latter. Conidia produced on V8-oatmeal agar differed significantly bet ween species in regard to lengths, widths and correlation coefficients between lengths and widths. No species differences in conidial wall t opography were seen with scanning electron microscopy. Only C curvispo ra produced abundant pulvinate conidiomata as cultures aged on potato dextrose agar; only C perennans produced synnemata without expanded ap ices on V8-oatmeal apr. On lesions of inoculated apple fruit C perenna ns produced significantly more conidia than C curvispora, but the spec ies did not differ with regard to appressorium formation or lesion siz e on fruit or canker extension on branches.