Effect of 2,4-Dichlorophenoxy Acetic Acid and Activated Charcoal on Callus Induction of Cocos Nucifera L. Hybrid MATAG Inflorescence

Cocos Nucifera Linn. Var. MATAG is a Dwarf coconut variety that had high demand in Malaysia but low supply. Vegetative propagation of high-yielding MATAG coconut by using in vitro cloning must be considered in contributing to increase coconut productivity. Thus, attempts were made to develop a protocol that would enhance callogenesis as a first preliminary step towards a protocol for mass propagation of C. nucifera L. var. MATAG. The anther isolated from immature inflorescence was used as explants and cultured on modified Eeuwens Y3 media in different concentrations of 2,4-dicholorophenoxy acetic acid (2,4-D) and activated charcoal. The highest callus induction percentage (31.25 ± 12.18) was observed in 20 mg/L 2,4-D. However, 2,4-D at any level tested were not statistically significant. Callus induction media supplemented with 0.5 mg/L activated charcoal gave the highest callusing percentage (25.89 ± 13.59 %) indicating a positive effect of activated charcoal on callusing even though the result obtained not significant compared to control (15.95 ± 6.76 %). But, activated charcoal supplemented in media produced a significant effect compared to control in reducing the percentage of browning. In conclusion, media supplemented with activated charcoal produced a higher rate on callus induction and preventing tissue browning in explant. Besides that, the anther and ovule explant may serve as an efficient explant to study the callus induction of C. nucifera L. var. MATAG and as a basis to screen the potential useful plant growth regulators for somatic embryogenesis.