EFFECT OF PEEL INJURY AND ENZYMATIC ACTIVITY OF THE FRUIT ON THE TOLERANCE OF TOMATO GENOTYPES TO ALTERNARIA INFECTION

Heat treatments, which resulted in a partial removal of the natural wax of tomato, as well as exposure to chilling conditions, markedly increased the susceptibility of the non-ripening nor mutant to infection. It was suggested that the ability of the pathogen to penetrate into the pericarp has a primary role in the relative resistance of tomato genotypes to Alternaria infection.

Following penetration into the pericarp a higher rate of lesion development was recorded in the mature normal fruit than in the mature mutant or hybrid fruits. However, rate of growth in the latters was higher than in the mature-green normal fruit. A correlation was drawn between the cellulolytic activity of the pathogen within the fruit tissues and the level of enzymatic activity of the fruit prior to infection.