Luz natural, sacarose e fitorreguladores na anatomia foliar e crescimento in vitro de abacaxizeiro micropropagado

Abstract

The objective of this work was to evaluate the effects of natural light, reducing the use of sucrose and growth regulators on in vitro culture of pineapple. Shoots of pineapple cv. Imperial were grown in different culture media: multiplication (MS + BAP 1.0 mg L-1 + NAA 0.25 mg L-1) and rooting (MS + NAA 0.25 mg L-1) plus sucrose (15 and 30 g L-1) and incubated in artificial and natural light for 60 days. After this period, anatomical and plant parameters were carried out. In the multiplication plase, highest number of shoots was obtained in a growth chamber (40 mol.m-2s -1, temperature of 25° C ± 1º C and 16 hours photoperiod), with an average of 40 shoots per explant. However, in vitro better growth was obtained using rooting medium in culture under natural light in the greenhouse (PPFD above 150 mol.m-2s -1, temperatures between 27 and 31.5º C). The variables of leaf indicated that the natural light provided greater thickness and high stomatal frequency, compared with the conventional micropropagation. Thus, it is concluded that the use of natural light in the micropropagation of pineapple is viable and makes plants more adapted to the process of acclimatization.