Resistance of Tomato Ripening Mutants and Their Hybrids to Botrytis cinerea

Fruits and peel extracts of nonripening nor and rin tomatoes suppressed germ-tube elongation in Botrytis cinerea, as compared with mature normal fruits. The highest level of resistance was shown by the nor mutant and its F 1 hybrid, suggesting that this character was transferred form the mutant to the hybrid fruit. Exposure to 0 C for 3 days or to hot water(52 C) for 5 min before inoculation markedly increased the susceptibility of normal fruits and partially broke the resistance of the previously resistant fruits.