Effects of Growth Regulators and Gelling Agents On In Vitro Regeneration of Chromolaena Odorata (L.) King & H. Rob.

Abstract

The present study describes successful in vitro regeneration systems in Chromolaena odorata (L.) King & H. Rob. by forced axillary bud break from nodal explants. Full strength Murashige and Skoog’s (MS) medium augmented with BAP at 8.88 µM resulted in maximum induction of shoots (4.6±0.25 shoots per explant). The shoots were promoted to proliferate by sub-culturing on MS medium (liquid, agar-gelled and phyta-gelled) fortified with 2.22 µM BAP and 0.571 µM IAA. This combination of MS medium solidified with phytagel yielded 17.6±1.2 shoots per explants per culture vessel after 5 weeks of incubation. Results showed that the quality of shoots on medium gelled with phytagel was better than agar gelled and liquid MS media. Rooting of regenerated shoots was achieved by in vitro and ex vitro methods. About 80% shoots rooted in vitro with 6.3±0.50 roots per shoot on half strength MS medium containing 2.46 µM IBA. Ex vitro method of rooting (12.1±0.10 roots per shoot) was achieved by treating the shoots with 245 µM IBA for 5 min upon 4 weeks of incubation with soilrite® in the greenhouse. Rooted plants were reallocated into paper cups having soilrite®: red soil in equal proportions for hardening. The acclimatized plants were subjected to field trial for 6 weeks and the percentage of survival rate was recorded as 96%. The developed protocol could be utilized for genetic transformation for for development of desired traits in C. odorata.