Abstract

TORRES A, Jhonathan  and  SANABRIA CH, María E. Effect of the development environment on the leaf anatomy of Cattleya jenmanii Rolfe and C. lueddemanniana Rchb.f. (Orchidaceae). Acta Bot. Venez. [online]. 2011, vol.34, n.1, pp.199-214. ISSN 0084-5906.

The orchids Cattleya jenmanii and C. lueddemanniana are important ornamental species, endemics of Venezuela. The commercial production is achieved by in vitro culture. During the acclimatization, there take place plant losses that imply additional costs. For the appropriate design of practices of culture in greenhouses, it is important to understand the effect of the acclimatization in the anatomy of in vitro plants. The intention of the present work was to describe and to compare the leaf anatomy of the two named species of orchids, grown in the orchidarium house and in two different moments of in vitro propagation (multiplication and acclimatization). Plants were cultured in the Murashige-Skoog medium (1962). The rooted vitroplants were acclimatized in a mist propagator during a week, humid chamber for four weeks and orchidarium for three weeks. The samples were processed by means of classical microtechnique procedures. The in vitro environment induced the thickness reduction of the leaf blade, epiderm and cuticle; mesophyll complexity reduction, hypoderm, fiber nodules, vascular bundles and idioblast absence. In the acclimatization stage, there was a trend to the acquisition of an similar structural organization to orchids house stage, but with characteristics of in vitro leaves. This suggests that the adjustment to the ex vitro conditions was not completed during eight weeks of acclimatization.

Keywords : Acclimatization; anatomy; Cattleya; in vitro propagation; orchids.

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