Cultural, Morphological and Pathogenic Variability in fusarium Oxysporum f. Sp. lycopercici Isolates from Major Tomato Growing Areas of Karnataka

Twenty three isolates of Fusarium oxysporum f. sp. lycopercici were collected from major tomato growing areas of Karnataka. They produced three kinds of spores, viz., microconidia, macroconidia and chlamydospors. Mycelia of the pathogen were white cottony to pink often with purple tinge or reddish colouration of the medium. Total isolates were assigned into three groups, on the basis of colony diameter, colony characters, sporulation and degree of pathogenicity. Isolates Fol-1, Fol-4, Fol-6 Fol-9, Fol-11, F ol-13, Fol-15 and Fol-21 showed abundant aerial mycelium and sporulation with maximum colony diameter (75 to 90.0 mm). They showed strong virulence with 75 per cent severity and wilting symptoms were noticed 14 days after inoculation.