Effects of immersion system and gibberellic acid on the growth and acclimatization of micropropagated pineapple

Micropropagation based techniques enable the mass production of pest- and disease-free stock plants. Aiming at optimizing pineapple [Ananas comosus (L.) Merril] micropropagation, a complete randomized experiment with three factors was established: immersion system (2 L twin flasks temporary immersion and permanent immersion); culture medium (supplemented or not with GA3); and shoot height class. The effects on regeneration rate (number of new shoots per 1 g fresh mass (FM) of inoculated microshoots), FM per shoot, and shoot survival were evaluated. Significant interactions (p<0.05) were observed in the regeneration rate, and simple effects (p<0.05) were detected for FM per shoot. All treatments resulted in a survival rate higher than 95%. Altogether, it was found that 2 L twin flasks temporary immersion and MS culture medium free of GA3 allowed the optimization of the protocol used. This treatment was tested with positive response in a biofactory system that uses sterile plastic bottles (5 L).