In vitro tomato fruit cultures demonstrate a role for indole-3-acetic acid in regulating fruit ripening

An in vitro system was used for the production of tomato (Lycopersicon esculentum) fruit in culture starting from immature flowers. This system produced small parthenocarpic (seedless) fruit in response to 10(-4) M indole-3-acetic acid (IAA) supplied in the medium. Other auxins, auxin conjugates and antiauxins tested were not effective or produced markedly fewer fruit, Additional IAA supplied to the fruit culture media before breaker stage resulted in an increase in the time period between breaker and red-ripe stages from 7 days without additional IAA to 12 days when 10(-5) mIAA was added. These results suggest that significant changes in the ripening period could be obtained by alteration of auxin relationships in tomato fruit.