Mass Propagation of Pineapple through in Vitro Culture

Abstract

A large number of shoots were obtained from dormant axillary buds excised from the crown of pineapple and cultured on MS nutrient medium supplemented with different concentrations and combinations of kinetin, benzyl adenine (BA), a-naphthalene acetic acid (NAA) and indole-3-butyric acid (IBA). Condensed nodal regions of the crowns were used as expiants. When the expiants were cultured directly on MS medium with 2.5 mg l^-1 BA + 0.5 mg l^-1 NAA multiple shoot buds formed. These shoots continued to proliferate through several subcultures with an average of 20 shoots per transfer but the shoots were too small to transfer to rooting medium. When the concentrations of BA and NAA were lowered to 1.25 mg l^-1 and 0.25 mg l^-1, respectively, and 1.25 mg l^-1 kinetin was added to the medium the shoots elongated and the number of shoots increased up to 30 per culture. When the expiants of meristem tip of crown were cultured on MS medium supplemented with 1.5 mg l^-1 NAA and 1.0 mg l^-1 kinetin callus was initiated within 3 weeks. This callus, when subcultured on MS medium with 1.5 mg l^-1 kinetin + 0.5 mg l^-1 NAA, produced large number of shoots. After four weeks these shoots along with calli were transferred to fresh medium of same constituents, where the old shoot buds elongated and many new buds also emerged. Shoots of both the categories rooted well, within two weeks, when they were excised individually and implanted in half strength MS medium with 2 mg l^-1 IBA. Eighty percent plantlets survived when transferred to open field. The technique described would be a promising method of propagation on a commercial scale and the regeneration technique via callus would be utilized for genetic improvement of the crop.