Tissue Culture of Moringa Oleifera Lam. And Determination of Antifungal Activity of Its Callus Extracts

Abstract

Moringa oleifera is both a tropical and sub-tropical tree with medicinal and nutritional properties valuable to humans. However, the tree is under threat due to drought and excessive harvesting of its parts (seeds, bark, leaves and pods) for food and medicine. Therefore there is need to explore alternative propagation methods to cope with increasing demand. In vitro propagation is therefore significant for rapid and enhanced production of planting materials free from diseases and for production of secondary compounds. This study aimed at regenerating Moringa oleifera in vitro and determining if its callus extracts can inhibit fungal growth. Dehusked and intact seeds were sterilized in 30% commercial bleach (JIK) for 15 minutess followed by 70% ethanol for 2 minutes and rinsed 3 times in sterile distilled water. The seeds were inoculated on Murashige and Skoog, (1962) (MS) media and half MS media and MS supplemented with 0.5, 2.5, 4.5 and 6.5 mg/l Gibberellic acid (GAз) to germinate. Callus was generated from inter nodal segments, leaf discs and hypocotyls of in vitro germinated seedlings on MS supplemented with 0.25, 0.5, 1.0 and 2 mg/l 2,4 di-chloro phenoxyacetic acid (2,4D), naphthalene acetic acid (NAA), thidiazuron (TDZ) or benzyl amino purine (BAP). Callus was subcultured to MS medium supplemented with different concentrations of BAP, NAA, metatopoline ribonucleotide (MTR), TDZ and kinetin (KIN) or their combinations to obtain shoots through somatic embryogenesis. Axillary shoots were induced from nodal explants on MS media supplemented with 0.1, 0.5, 1.0, 2.0 and 3 mg/l BAP, NAA, TDZ, MTR or KIN singly or their combinations. Micro shoots were rooted on MS basal or MS supplemented with 0.01, 0.1, 0.5, 1.0 and 2 mg/l NAA, BAP or MTR. The rooted shoots were then acclimatized and hardened on a mixture of vermiculite and peat moss (1:3) in the glass house. Callus and leaf extracts were tested against Candida albicans, Aspergillus flavus and Fusarium semitectum. The results were then subjected to two way analysis of variance (ANOVA) and means separated by Turkey’s HSD test at p ≤ 0.05. Intact seeds on either MS or half MS medium germinated within 8-14 days. Seeds with seed coats removed started germinating 3 days post inoculation...........