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

In vitro control of floral transition in tomato (Lycopersicon esculentum Mi ll.), the model plant for autonomously flowering species has been investiga ted using the late flowering mutant uniflora (uf), Apices collected from tr uly vegetative plants were cultivated on solid media supplemented with diff erent combinations of growth regulators and chemicals, Several chemical fac tors 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 f ound 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 stud y suggests that tomato could constitute an adequate model to investigate th e genetic and physiological control of floral transition and contribute in unravelling pathways which are constitutively regulating this important ste p of plant life cycle.