A rapid Agrobacterium-mediated transformation protocol for tomato (Solanum lycopersicum L.) cv. PKM-1

Factors that influence transformation efficiency such as age of explants, plant growth regulator concentration, antibiotic concentration, Agrobacterium density, and infection time were optimized with a view to establish a high-throughput transformation protocol for tomato (Solanum lycopersicum L.) cv. PKM-1. Seedling explants were transformed using a binary vector carrying nptII gene, conferring kanamycin resistance by Agrobacterium mediated transformation. Transformation efficiency of 27 % and 17 % respectively was observed when cotyledon and hypocotyl explants were collected from 7 and 9 day old seedlings, co-cultivated with an Agrobacterium suspension of O.D600 of 0.4 and 0.2 for 30 and 10 minutes infection time respectively. Better shoot development was observed when shoots induced on cotyledonary and hypocotyl explants were cultured on modified MS medium containing 0.5 and 1 mg/L zeatin respectively. Supplementation of medium with 200 mg/L timentin effectively suppressed Agrobacterium overgrowth. Furthermore, the time required from inoculation of explants with Agrobacterium to transfer of transgenic tomato plants to soil was only 70 days as compared to 3 to 4 months in standard tomato transformation protocols.