Histopathology of Colletotrichum gloeosporioides f. sp. aeschynomene on Northern Jointvetch

Publisher Website
Google Scholar
Abstract
The histopathological relationship of C. gloeosporioides f. sp. aeschynomene with its host. Aeschynomene virginica, was investigated by microscopic examination of diseased seedlings and inoculated explants. Inoculation of A. virginica seedlings with suspensions of C. gloeosporioides, resulted in the formation of pinpoint lesions (0.5-1 mm diameter) on stems or explants within 48 h after inoculation. Lesions found within 48 h after inoculation resulted from direct penetration of trichome bases. Spores of the fungus germinated and produced appressoria within 4-5 h after inoculation, but did not penetrate the stem epidermis via the appressoria until 48 h after inoculation. Infection resulted in the formation of stem lesions, 2-3 cm long, which encircled the stem within 6-8 days after inoculation. Intracellular mycelium grew within the cortex, cambium, xylem and pith ray tissues. Death of A. virginica seedlings was caused by collapse of infected stem tissues. Coalescence of lesions enhanced girdling of stems and hastened death. The fungus sproulated abundantly on lesion surfaces.