Germinação e desenvolvimento in vitro de embriões zigóticos de tucumã-do-amazonas (Astrocaryum aculeatum Meyer arecaceae)

Abstract

Astrocaryum aculeatum Meyer (Arecaceae), popularly known by tucumã, is a palm tree that occurs in the Amazon and presents a potential market of food and crafts. Has great economic importance, mainly the different products that it can be extracted and used. The specie is characterized by delay in germination, a fact that discourages their cultivation. Thus, information that enable methods and techniques that accelerate the seedlings production is important as a stimulus to the specie cultivation. The aimed of this study was to establish protocols for tucumã in vitro germination and development of zygotic embryos through tissue culture techniques. The tests were performed at the Centro de Biotecnologia da Amazônia. We evaluated the effects of different antioxidants (activated charcoal, ascorbic acid and polyvinylpyrrolidone), the means were tested semi solid MS and Y3 with 0.0 mg L-1 and 2.0 mg L-1 indolylacetic acid (IAA) in the elongation phase, while in the rooting phase, the treatments consisted of four concentrations of naphthalene acetic acid (NAA) (0, 2.5, 5, 10 mg L-1). The cultures remained in a growth chamber with temperature set at 25 ± 1 ° C, light intensity of 30.0 μmols.m-2.s-1 and 16-hour photoperiod. During the acclimatization plants were kept in a greenhouse with intermittent misting system for 60 days. The substrates used were sand, coconut fiber, Vivato®, coconut fiber x sand, coconut fiber x Vivato®, sand and Vivato®, sand x coconut fiber x Vivato®, all in the same proportions. The antioxidant assay results showed that there is no need for the use of antioxidants as MS medium (control) showed 86% germination and absence of oxidation. In stretching phase, MS medium supplemented with 2.0 mg L-1 IAA, was superior to other treatments, developing plants with an average height of 6.18 cm. For rooting, the treatment with 10.0 mg L-1 NAA was higher, with an average production of 9.0 roots per plant, with a rooting percentage of 75.0%. During the acclimatization phase, the substrate Vivato® showed superior results to the other, with an average increase in height of 10.25 cm and launch of five new leaves