Callus formation and organogenesis of tomato (Lycopersicon escu-lentum mill variety Thilina)

This study was conducted to investigate the effects of explant source and hormone concentrations on the cal-logenesis, 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 evalu-ate 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 Ki-netin, 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.