Aggressiveness of Fusarium oxysporum and F. verticillioides isolates on stone and scots pine under greenhouse conditions

Abstract

Scots pine (Pinus sylvestris) and Stone pine (Pinus pinea) are two important species used in re-forestation that are subject to damage by damping-off fungi in forest nurs-eries. Twenty-two isolates of Fusarium oxysporum and F. verticillioides from diseased seedlings of eight different hosts were tested for aggressiveness on seeds and seed-lings of both pine species, including the effects on seedling emergence and mortal-ity. Scots pine was more susceptible to damping-off than Stone pine, as indicated both by reduced seedling emergence and elevated seedling mortality. The impact of F. oxysporum and F. verticillioides on seeds and seedlings did not differ significantly for either pine species. Our findings support previous studies that found that these are damping-off pathogens on the studied pines. Whereas most isolates proved to be pathogenic, some isolates of both Fusarium species showed to be non- pathogenic.