Direct Adventitious Shoot Regeneration from Triploid Watermelon Cotyledons

Abstract

An in vitro regeneration system was established for cotyledon explants of triploid watermelon (Citrullus lanatus Thumb.). Full strength MS medium supplemented with 0.2 mg.L-1 IAA in combination with different concentrations of BAP was employed for investigating adventitious shoot formation. Medium containing 1.5 mg.L-1 BAP and 0.2 mg.L-1 IAA was suitable for direct shoot induction from cotyledon explants. Adventitious shoots were elongated for 3 weeks on medium containing 0.5 mg.L-1 GA3 before transferring into rooting medium. Frequency of root induction achieved approximately 88% with an average of 4.3 root per shoot on half strength MS medium supplemented with 0.5 mg.L-1 IBA. Rooted shoots were successfully acclimatized in potted soil mixture with survival rate of 82.6%.