In vitro propagation and fruiting of pineapple

摘要

Pineapple (Ananas comosus L. Merr. er. 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 monthes (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 rain, HgCl_2 (0.1 percent) for 30 sec and ethanol (70 percent) for 5 see 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/l) 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-basalmedium contained MS salts at a half strength and supplemented with different doses of indole-butyric acid (IBA) or #alpha#-naphthalene-acetic acid (NAA) demonstrated that the medium supplemented with NAA (2 mg/l) was the best for rooting. The ex vitro growth of the rooted plantlest in different mixes of peatmoss and sand for 2 monthes 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.