Rapid in vitro multiplication of the ethnomedicinal shrub, Acacia caesia (L.) Willd. (Mimosaceae) from leaf explants

Abstract

ObjectiveTo develop an efficient protocol for in vitro multiplication of the ethnomedicinal shrub Acacia caesia (A. caesia) L. Willd., MethodsLeaf explants were inoculated on MS medium supplemented with TDZ and NAA for callus induction. Subculturing experiments were conducted by using leaf derived calli for shoot proliferation on MS medium fortified with various growth regulators like IBA, TDZ, BAP and GA3. The regenerated shoots were rooted in half strength MS medium supplemented with various concentrations of IBA, IAA and Kn. After roots were developed, the plantlets were transplanted to pots filled with garden soil, sand and vermicompost and kept in growth chamber with 70%–80% humidity under16h photoperiod. After acclimatization, the plantlets were transferred to the garden and survival percentage was calculated. Data were statistically analyzed and means were compared using Duncan's Multiple Range Test (P <0.05). ResultsAn in vitro multiplication protocol was developed for the locally demanded medicinal plant species, A. caesia by using leaf explant. The study revealed that the callus formation was effective in MS medium containing TDZ and NAA at 1.5 and 0.3 mg/L respectively. Shoot induction was most successful in MS medium supplemented with combination of the auxin, IBA and cytokinin, TDZ at 2.0 and 0.5 mg/L respectively. A single leaf explant was capable of producing 12 shoots/callus after 30 days of culture. The other supplementation in MS medium with IBA and Kn at 2.0 and 0.4 mg/L respectively produced higher rooting frequency, roots/shoot and root length. The survivability rate of leaf callus derived plantlets was significantly higher (84%) in the hardening medium composed by garden soil, sand and vermicompost (1:1:1) by volume. ConclusionsA significant progress has been made in the in vitro regeneration system of this medicinally important plant species, A. caesia.