Callus formation and organogenesis of tomato (Lycopersicon esculentum Mill variety Thilina).

This study was conducted to investigate the effects of explant source and hormone concentrations on the callogenesis, calli growth, plantlet regeneration and rooting of a local tomato variety (Lycopersicon esculentum mill. variety ‘Thilina’). Different combinations of Benzyl Adenine (BAP) and 2, 4-Dichlorophenoxyacetic acid (2, 4-D) were used with hypocotyl, leaf and root explants in a completely randomized design with five replicates to evaluate the success in plantlet regeneration. Regenerated healthy shoots sub cultured in to MS medium with various concentrations of Indole-3-butric acid (IBA) for rooting. After one month the weight of fresh callus, number of regenerated shoots and roots were evaluated. Anova (DMRT) test shows there were significant effects at p<0.05 level. Combination of BAP (0.1mgl -1 ) with 2.4-D (2.0mgl -1 ) and hypocotyl explant produced the best quality fresh callus in highest weight. The best hormonal combination for shoot regeneration (4 shoots/explant) was 0.1mgl -1 NAA and 0.5mgl -1 Kinetin from callus. Maximum direct regeneration was observed on MS medium containing 0.5mgl -1 Kinetin, 2.0mgl -1 BAP, 0.1mgl -1 1-Naphthaleneacetic acid (NAA) and 100mgl -1 my-inositol within 15-20 days (4 shoots/explant). Leaf bud revealed to be better explants for direct regeneration. Highest root number per plantlet was observed with 2.0mgl -1 IBA.