MORPHOLOGICAL AND CHEMICAL ALTERATIONS IN BOTRYTIS-CINEREA EXPOSED TOTHE DICARBOXIMIDE FUNGICIDE VINCLOZOLIN

Treatment of actively growing Botrytis cinerea hyphae with micromolar concentrations of the dicarboximide fungicide vinclozolin resulted in significant alterations in the growth rate, morphology, and chemical c omposition of the cells. The addition of vinclozolin resulted in an im mediate and severe reduction in the hyphal growth rate and a retardati on in the emergence of the second germ tube. Cells treated with vinclo zolin had a lower content of pool metabolites than control cells, and this difference increased with time of exposure to the fungicide. In c ontrast, vinclozolin-treated cells had a higher chitin concentration t han control cells. These biochemical alterations were followed by the disorganization and clearing of cells, and by the appearance of dense and dark masses outside the hyphae, presumably composed of cell debris . Hyphae exposed to vinclozolin were more curved and branched and had shorter cells than the controls. The results indicate that vinclozolin causes a slow but generalized leakage of pool metabolites; this relea se precedes cell lysis and is not the result of a rapid and gross dama ge to the cytoplasmic membrane.