In vitro control of floral transition in tomato (Lycopersicon esculentum Mill.), the model for autonomously flowering...

In vitro control of floral transition in tomato (Lycopersicon esculentum Mill.), the model plant for autonomously flowering species has been investigated using the late flowering mutant uniflora (uf). Apices collected from truly vegetative plants were cultivated on solid media supplemented with different combinations of growth regulators and chemicals. Several chemical factors implicated in the promotion of floral transition of the uf mutant have been identified: sucrose, cytokinins and nitrogenous nutrients have all to be supplied at optimal concentrations. In contrast, gibberellic acid was found to be inhibitory. These results are discussed in relation to knowledge accumulated on the nature of the flowering signals circulating, at floral transition, in other plants, especially in photoperiodic species. This study suggests that tomato could constitute an adequate model to investigate the genetic and physiological control of floral transition and contribute in unravelling pathways which are constitutively regulating this important step of plant life cycle.