An efficient protocol for <i>in vitro</i> organogenesis and antioxidant studies in <i>Melia dubia</i> Cav

Abstract

Melia dubia Cav. (Meliaceae) is a multipurpose tree of tropical and subtropical regions mainly cultivated for its medicinal and industrial importance. Due to its versatile properties, it has been depleted in its natural environment. Moreover due to sluggish and poor seed germination, there is a threat of its gene pool exclusion from the natural habitat. The alternative method for conservation and efficient mass propagation is thus need of the hour. As per the extensive literature survey there is no report on efficient protocol for mass propagation of M. dubia through callus organogenesis. Therefore, the present work was aimed to develop in vitro organogenesis protocol for rapid and large scale production of planting material. From our results, maximum callus percentage, callus weight and fragile callus was observed on 1.0 mg/l benzylaminopurine (BAP) in combination with 0.5 mg/l naphthalene acetic acid (NAA). The callus differentiation was achieved at different concentrations of BAP and indole acetic acid (IAA). Multiple Shoot number per callus propagule 5.30 was observed on 0.5 mg/l BAP and 1 mg/l IAA concentration. The maximum rooting percentage (78.5%), root number per explant (4.33) and root length per explant (4.41 cm) was observed at 0.5 mg/l indol butyric acid (IBA) after 30 days of inoculation. Further the total flavonoid content, phenolic content and antioxidant properties of leaves of in-vitro regenerated plants where studied. Total flavonoids and phenolic content in leaves of in vitro Melia dubia was 0.56 ± 0.8 mg quercitin equivalent (QE) and 2.97 ± 0.17 mg gallic acid equivalent (GAE) respectively. The antioxidant property was further assed through measurement of DPPH radical scavenging activity. The in-vitro regeneration protocol can be exploited for commercial cultivation and fulfilling the growing demand for fresh explant material through mass propagation of M. dubia an economically important plant species.

Key words: Melia dubia, antioxidant, indole-3-butyric acid, flavonoids and phenolics.