Propagation and fruiting of pineapple [ananas comosus L. Merr.] throuth tissue culture techniques

ABSTRACT

Pineapple [Ananas comosus L. Merr. CV. Queen] was propagated through in vitro culture using stem-tip explants. The produced plantlets were hardened-off for 2 months and acclimatized for 3 months in peatmoss and sand mixes, then grown for 13 months [fruiting stage] under greenhouse conditions. In a preliminary experiment; it was indicated that NaOCL was the most efficient microbicidal and soaking explants in solutions of NaOCL [1.0 percent] for 20 min, HgCl2 [0.1 percent] for 30 sec and ethanol [70 percent] for 5 sec resulted in totally microbial-free explants [i.e., the best surface-sterilization method]. Culturing the microbial-free explants on MS [Murashige and Skoog]-basal media [liquid and solid] supplemented with different doses of benzyl-adenine [BA] showed that both media supplemented with BA [1.0 mg/1] were the best for multiplication, but the liquid medium appeared to be better than the solid. Transferring shootlets, regenerated on the best multiplication medium, to solid MS-basal medium contained MS salts at a half strength and supplemented with different doses of indole-butyric acid [IBA] or a-naphthalene-acetic acid [NAA] demonstrated that the medium supplemented with NAA [2 mg/1] was the best for rooting. The ex vitro growth of the rooted plantlets in different mixes of peatmoss and sand for 2 months under hardening-off conditions [hardening-off stage], revealed that the mix of 3 peatmoss and 1 sand was the best for growth and development. Therefore, plants were further grown for 3 months in this mix [acclimatization stage], then transplanted in the greenhouse soil under controlled conditions where flowers and fruits [1.65 +/- 0.45 kg/fruit] were developed after 11 and 13 months, from transplanting, respectively