Abstract
The role of different temperature regimes (low, 18 °C day: 15 °C night (LTR); intermediate, 23 °C day: 18 °C night (ITR); and high, 28 °C day: 23 °C night (HTR)) in the development of tomato (Lycopersicon esculentum Mill.) flowers was studied. In general, flowers produced in LTR contained significantly greater numbers of petals, stamens, carpels, and locules than did plants grown in HTR. In ITR, the number of these organs was intermediate to plants grown in LTR and HTR, but was not significantly different from them in all cases. Gibberellic acid (GA3) also induced an increase in the number of petals, stamens, carpels, and locules; however, its effect was much greater on plants grown in ITR and HTR than on LTR, implying that LTR may produce at least part of its effect through increased levels of endogenous gibberellins. The intensity of response to different temperature regimes was variable for each of the three cultivars studied.