meta-Topolin induced in vitro regeneration and metabolic profiling in Allamanda cathartica L.

Abstract An efficient micropropagation protocol has been optimized through nodal explant in Allamanda cathartica, a potential woody climber using a new aromatic cytokinin, meta-Topolin. Of the different cytokinin tested, higher number of shoots (10.5 ± 0.16) with higher shoot length (6.1 ± 0.09 cm) was observed on Murashige and Skoog (MS, 1962) medium supplemented with 3.0 μM meta-Topolin (mT). The combined effect of cytokinin-auxin (3.0 μM mT + 0.5 μM α-naphthalene acetic acid (NAA)) resulted in the production of 26.2 ± 0.32 mean shoots per explant. The inclusion of 5.0 μM ammonium nitrate (NH4NO3) to the optimized (MS + 3.0 μM mT + 0.5 μM NAA) significantly influenced the shoot procreation rate by producing 58.8 ± 0.46 mean shoots per explant in 96.80 % culture after 12 weeks of incubation. The higher rooting response in the microshoots (6 cm) was obtained on ½ MS medium containing 0.5 μM indole-3-butyric acid (IBA) which yielded a higher of 6.5 ± 0.16 mean roots with an average of 5.4 ± 0.16 cm root length in 97.80 % cultures. Among the various treated samples, higher flavonoids and quercetin content was recorded in the leaves of plantlets raised on 3.0 μM mT + 0.5 μM NAA + 5.0 μM NH4NO3, yielding 174.32 mg QE/g and 55.2 mg/g flavonoid and quercetin per gram of extract respectively. The protocol assures a speedy production of plantlets that can be used for isolation of biologically active compounds to be utilized by the pharmaceutical industries for the treatment of various diseases.