Virus-induced over-expression 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) could shorten the generation time in tomato due to accelerated tomato flowering and ripening by 14-21d and a 2-3 fold increase in the number of flowers and fruit compared with non-infected or empty vector-infected plants. The Arabidopsis FT was more effective than the tomato orthologue SFT and there was no alteration of the 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.