Estímulo do comportamento fotoautotrófico durante o enraizamento in vitro de Annona glabra L. , II. Aspectos da anatomia da folha antes da aclimatização

Abstract

The low survival during the acclimatization of plants regenerated through the micropropagation has been attributed, among several factors, to low the photosynthetic capacity. The development of photoautotrophic in vitro culture systems appears as potential possibilities of increasing the efficiency of the micropropagation. The aim of this work was to compare the leaf anatomy of plants of Annona glabra L. cultivated in vitro, under photoautotrophic and heterotrophic conditions, during the phase of rooting, with ex vitro (maintained in greenhouse under photosynthetic acitve radiation of 130-170µmol.m-2.s-1, without control of room temperature). Shoots were rooted in photoautotrophic conditions (sucrose-free medium with aeration) heterotrophic conditions (medium with sucrose without ventilation). The medium of culture was the WPM supplied of 164.4mM of activated charcoal and 4.9µM AIB. After 30 days of culture measurements of the foliar thickness of the epidermises abaxial, adaxial, parenchyma spongy, palisade and limb one. Verified variations in the anatomy of the leaves, that had been characterized by an increase in the leaf thickness in accordance with the established aeration. In vitro photoautotrophic rooting of plants Annona glabra L stimulated an anatomical and physiological development similar to the one observed in an ex vitro condition, which may minimize the losses at the acclimatization process.