In vitro shortening of generation time in Arabidopsis thaliana

Shortening of generations is very important for gene validation and a rapid exploitation of genetic novelties. Even if the life cycle of Arabidopsis thaliana is theoretically short, shortening it further would be useful. We developed a strategy where seeds germinated on medium with picloram (0.1 mg/l) and benzylaminopurine (0.5 mg/l) set seed about 40-45 days after sowing. Green seeds from immature siliques (second generation) are sown on half-strength, hormone-free MS medium where they flower and fruit much faster than the first generation (between 20 [C24] and 26 [Col] days/generation). A cold treatment was not needed for germination of immature seeds, and the duration of each cycle could thus be halved compared with the first generation. This strategy, allowing comfortably more than 10 generations per year, may be helpful for genetic studies using this model plant species.