Aspectos bioquímicos e fisiológicos da palma forrageira Opuntia stricta Haw sob distintos sistemas de cultivo in vitro

Abstract

The Opuntia stricta Haw, cactus of great economic importance as forage in northeastern Brazil, was subjected to different in vitro systems and their performance was assessed by physiological and biochemical variables. We established three different cropping systems: temporary immersion system (TIS), with low frequency of immersion (immersion of one minute every 48 hours) and high-frequency TIS (immersion for five minutes every three hours); static culture in semi-solid medium (6.0 g.L-1 agar); static culture in liquid medium. The middle for inducing proliferation in vitro consisted of Murashige and Skoog (1962) salts and vitamins plus 30.0 g.L-1 sucrose and 0.0, 0.25, 0.5 or 1.0 mg.L-1 6-benzilaminpurine (BAP). Cultures were maintained in a growth room with 25 ± 2 º C under cool white light (40 mol.m-2.s-1), with 16 hours photoperiod. The experimental design was completely randomized factorial arrangement with 4 x 4 (cropping systems x BAP concentrations in the middle). After cultivation in vitro shoots of each treatment were acclimatized. Biochemical and biometrics analysis were performed on the material in vitro and biometrics on the acclimatized material. The static culture on solid medium, provided more stability since the multiplication by the acclimatization of the seedlings, while the systems with liquid presented limitations in some stages of micropropagation. The vitrification and the presence of betacyanin can be used as quality indicators physiological of the Elephant Ear Mexicana and its potential for acclimatization.