Pumkin seedlings (Cucurbita maxima) were inoculated with the fungus Sclerotinia sclerotiorum (Lib.) de Bary. Center regions of non-infected and infected cotyledons of various lengths were cut into 1 x 2 mm strips and processed for ultrastructural investigations. Complementary portions of opposing non-infected cotyledons were also processed as control tissue, and contained fewer storage products in cells than cotyledons of comparable size from non-infected plants. Young non-infected cells contained distinct lipid bodies, protein bodies and electron dense inlusions which were translocated out of older cells by abundant plasmodesmata. Initally, infected cells became plasmolyzed, followed by breakdown of the cytoplasm. Host cells were generally affected only 4-6 cells from the infection front. Many infected cells had abundant rough endoplasmic reticulum and all organells were eventually completely disrupted. Action of enzymes from fungal cells did not appear to be limited to the area immediatedly adjacent to hyphal cells.
College and Department
Plant and Wildlife Sciences
BYU ScholarsArchive Citation
Richtsteig, Mark Edward, "Ultrastructural investigations of the host-parasite interface of pumpkin cotyledons and the fungus Sclerotinia sclerotiorum" (1975). Theses and Dissertations. 7967.
Host-parasite relationships; Pumpkin; Phytopathogenic fungi