Temporary immersion system: An efficient technique to improve the Plumeria rubra L. scale-up

Plumeria rubra L. (Frangipani), native to Central and South America, is widely diffused in Sicily since its arrival in the early 1800s. The usual way to propagate Plumeria is by cuttings, but lately, an in vitro protocol has been developed to improve the propagation of the species. Though the in vitro multiplication of Plumeria reached a higher rate than the traditional propagation technique, the number of plantlets obtained is still not sufficient for the commercial needs. This study intends to add knowledge on temporary immersion system (TIS)bioreactors applied to improve the multiplication process. The benefits of TIS protocols, when compared with those that employ semi-solid or liquid media, have been attested for economically-important species, and appears to be an increasing interest in this technique. The multiplication rate of Plumeria increased if compared to the gelled medium and due to the duration and frequency of the immersion cycles, the plantlets showed a higher autotrophy performance and, consequently, a better acclimatization response.