MICROPROPAGATION OF COCONUT THROUGH PLUMULE CULTURE

Abstract

Plumule tissues have found to be more responsive explants for clonalpropagation of coconut. In the present study, the feasibility of using plumuleexplants for clonal propagation of a local coconut variety (Sri Lanka Tall)was assessed. Plumules were cultured in three basal media (MS, Y3 and72) supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D) (24 - 400 \M)and activated charcoal. Somatic embryogenesis and plant regenerationwere induced by incorporating of abscisic acid (ABA) into the medium.Attempts were made to improve plant regeneration by applying high agarconcentration-induced water stress, cytokinin or silver nitrate in combinationwith ABA.The results revealed that callus can be initiated from plumule explantscultured in all three basal media tested. The callus formation depended onthe concentration of 2,4-D in the media and the best effect was observedwith the lower level (24 jiM) tested. The plant regeneration frequencyobserved with ABA treatment was 4.4 %. The combination of ABA with highagar concentration-induced water stress doubled the plant regenerationfrequency. About 50 % of the regenerated plants could be successfullyacclimatized and field planted.The results of the study indicate the possibility of regenerating plants fromplumule explants of coconut. The method can be used for multiplication ofimproved seed material. However, the plant regeneration efficiency shouldbe further improved for mass scale propagation of coconut using plumuleexplants.