PLANT-REGENERATION FROM PROTOPLASTS ISOLATED FROM CELL-SUSPENSION CULTURES OF THE WILD TOMATO, LYCOPERSICON-CHILENSE DUN

A protocol has been established for rapid, high frequency plant regeneration from protoplasts of the wild tomato species Lycopersicon chilense Dun. Cell suspension cultures were obtained from calli initiated from seedling stem explants. Protoplasts were isolated from cell suspensions by an overnight one-step enzyme digestion, purified by washing in salts solution and cultured in liquid medium. Dilution of liquid medium every 3 days, with medium containing low levels of growth regulators and sucrose, was critical for sustained colony formation. Up to 70% of protoplast-derived calli regenerated shoots when cultured on agar-solidified medium with Murashige & Skoog (1962) salts and vitamins, 2.0 mg l-1 zeatin and 0.1 mg l-1 indole acetic acid for 21 days, followed by transfer to the same medium lacking indole acetic acid.