MORFOLOGIA DE CALOS DE Eucalyptus urophylla CULTIVADOS in vitro SOB CONCENTRA??ES DE BORO E CáLCIO

摘要

O boro e o cálcio s?o nutrientes essenciais para o desenvolvimento vegetal, contudo existem poucos registros da atua??o desses elementos em nível nutricional. Visando avaliar possíveis implica??es desses nutrientes no desenvolvimento morfológico de Eucalyptus urophylla, calos foram cultivados in vitro sob concentra??es de boro (0, 25, 50, 100 e 200 μM de H3BO3) e cálcio (0; 3,75; 7,50; 11,25 e 15,00 mM de CaCl2). O experimento foi conduzido no delineamento inteiramente casualizado, no arranjo fatorial (5?x?5) contendo 5 repeti??es. Aos 21 e 31 dias foram avaliados os calos quanto à morfologia externa e interna. Foi possível verificar que nos dois períodos avaliados as concentra??es de boro e cálcio interferiram significativamente tanto na morfologia externa como na interna, resultando em respostas diretas com aspectos visuais das estruturas calogênicas. Os resultados mostraram que as combina??es de 25?μM de B com 0; 3,75; 7,50; 11,25 e 15,00 mM de Ca, aos 21 dias, apresentaram menores prejuízos ao desenvolvimento das raízes, o que favoreceu adequadamente a forma??o do órg?o. A produ??o de biomassa seca foi influenciada diretamente pela concentra??o de boro, sendo esse efeito constante para todas as doses de cálcio estudadas e para ambas as idades avaliadas.Palavras-chave:? Altera??es morfoanat?micas; calogênese; nutri??o mineral; cultura de tecidos vegetais.?AbstractMorphology of Eucalyptus urophylla callus, cultivated in vitro under boron and calcium concentrations. Boron and calcium are essential nutrients in plant development, but there are few registers of the common action of these nutrients in vegetable. In order to identify and quantify the possible implications of these micro and macronutrients in the morphogenetic development of Eucalyptus urophylla, callus were cultivated in vitro with different concentration of boron (0, 25, 50, 100 e 200 μM H3BO3) and calcium (0, 3.75, 7.50, 11.25 e 15.00 mM CaCl2). The experiment was completely randomized design in factorial arrangement (5 x 5) with 5 replications. It was evaluated after 21th and 31th days of culture the relation of external and internal morphology. It could be verified that in two evaluations periods the combined of boron and calcium had intervened in aspects of the internal e external morphology that had caused direct answers in visual aspects of the calluses. The combinations of 25 μM B with 0, 3.75, 7.50, 11.25 e 15.00 mM Ca in 21th day, were less harmful of the roots favoring appropriately organ development. The production of dry matter weight was directly influenced by boron concentration and this effect was constant for all calcium concentration and for both evaluated days.Keywords: Morphoanatomic alterations; callogenesis; mineral nutrition; vegetable tissue culture.