Abstract

The need for alternative strategies to obtain transgenic cotton via apical shoot was necessitated due to the recalcitrance of cotton regeneration from somatic embryogenesis, this has greatly slowed down the development of transgenic cottons. To this effect, an optimized regeneration system from apical shoot was developed for three varieties of cotton. Ninety-five percent seed surface sterility was observed in seed germination using a combination of hydrogen perioxide and Clorox as sterilizing medium. Highest shoot elongation rate was achieved on MS supplemented with 2.5 mg/L BAP + 0.1% (w/v) AC, rapid shoot growth occurred with kinetin supplemented media. Rooting efficiency of the three improved cultivars of cotton (Gossypium hirsutum), Samcot 9,11 and 13 were optimized using the optimum medium for rooting of difficult-to-root in vitro regenerated shoots of cotton which consist of MS basal salts and modified MS vitamins, supplemented with 3% sucrose, 0.2 mg/L IBA, without activated charcoal. In the end, an improved regeneration protocol with rooting efficiency up to 47% and regeneration rate up to 87% by combining rooting induction, indole acetic acid (IAA) shock and graft technique was developed.

Key words: Allium sativum, cotton tissue culture, transgenic plant, optimized regeneration of cotton.