Callus Production and Resin Induction of Agarwood (Aquilaria crassna)

Abstract

Agarwood is widely known for its fragrant resinous heartwood, refers to species in following four genera: Gyrinops, Aetoxylon, Gongystylis and more commonly, Aquilaria in the family Thymelaeaceae. This species is continuously exploited due to its precious resinous heartwood which is the source of expensive agar oil used in the production of high grade perfumes as well as in traditional medicines. The main aim of this study was to establish a callus production protocol from Aquilaria crassna which may serve as an important option for direct extraction of agar oil through in-vitro culture. Large scale production of callus tissue is needed for this purpose. An efficient callus regeneration protocol was established through leaf proliferation in Aquilaria crassna using Murashige and Skoog (MS) medium supplemented with plant growth substances: a Napthalene acetic acid (NAA) and 6-Benzyl aminopurine (BAP). The leaf ex-plants were collected from potted mother plants that were maintained inside shade house. Experiments were carried out to find out the best surface sterilization method for ex-plants and best hormone combination for callus induction. The best Clorox concentration for surface sterilization was applied for ex-plants with different level of NAA and BAP combinations.MS medium was used for callus induction. The best callus growth was obtained in the MS medium supplemented with BAP (0.5 mg/1) + NAA (3mg/l) giving the highest fresh (7.368 g) and dry cell biomass (1.203 g). Induced calli were transferred to MS medium containing Salicylic acid, Ferric chloride and Formic acid to check whether artificial resin induction could be obtained. Two weeks after, the calli grown on different chemicals were subjected to Thin Layer Chromatography (TLC) and compared with standard Agarwood resin as a control. The used levels of chemicals were found to be ineffective for resin induction in callus cultures.