Resistance of Tomato Ripening Mutants and Their Hybrids to Botrytis cinerea. Gila Lavy- Meir, Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel. Rivka Barkai-Golan, and E. Kopeliovitch. Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel, and The Hebrew University of Jerusalem, Faculty of Agriculture, Rehovot, Israel. Plant Dis. 73:976-978. Accepted for publication 13 February 1989. Copyright 1989 The American Phytopathological Society. DOI: 10.1094/PD-73-0976.

Fruits and peel extracts of nonripening nor and rin tomatoes suppressed germ-tube elongation in Botrytis cinerea, as compared with mature normal fruits. Similar levels of suppression also were seen with mature-green normal fruits. Contact inoculation with a diseased tomato fruit was used to determine the relative resistance of the mutant fruits and their hybrids to Botrytis infection. Resistance was indicated by the prolongation of the incubation period necessary for infection and the reduced incidence of rot during storage. The highest level of resistance was shown by the nor mutant and its F₁ hybrid, suggesting that this character was transferred from 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. We suggest that the relative resistance of the nonripening mutants and the nor hybrid to infection by B. cinerea is diminished by environmental conditions that favor penetration. The results also suggest the presence in the mutant tomato fruit of factors that suppress conidia germination and may be involved in their resistance to infection.