CYTOPATHOLOGICAL RESPONSES OF PICEA-ABIES SEEDLING ROOTS CHALLENGED IN-VITRO BY A NECROTROPHIC FUSARIUM-AVENACEUM (FR) SACC

Interaction of the necrotroph Fusarium avenaceum with seedling roots o f Norway spruce was studied. The results showed that Norway spruce see dlings were susceptible to the pathogen but disease progression and se verity was dependent on inoculum potential. Host recognition of the pa thogen marked by hypersensitive browning reactions occurred late, thus making successful resistance to cellular damage impossible. Such host resistance responses were mostly in the form of lignification, accumu lation of electron dense materials and papillae formation.