Virus-induced overexpression of heterologous FT for efficient speed breeding in tomato.

Potato Virus X (PVX) vectors expressing the Arabidopsis thaliana FT or tomato FT ortholog SINGLE-FLOWER TRUSS (SFT) accelerated tomato flowering time by 14-21d and increased by 2-3 fold the number of flowers and ripe fruit compared with non-infected or empty vector-infected plants. The Arabidopsis FT was more effective than the tomato orthologue and there was no alteration of the plant architecture, leaf, flower, or fruit morphology. The virus is not transmitted to the next generation and viral vectors with expression of a heterologous FT will be a useful approach to speed breeding in tomato and other species.