Semina: Ciências Agrárias (May 2003)
Rooting of west indian cherry cuttings under indo-butiric acid concentrations / <br>Enraizamento de estacas de acerola sob concentrações de ácido indol-butírico
Abstract
Oncidium varicosum is a native Brazilian orchid popularly known as ‘Golden Shower´ because of its very ramified inflorescence and many yellow flowers. The carboydrate type and concentration are important in promoting plantlet development of in vitro orchids. The present study was carried out to asses the effect of different carbohydrate sources and concentrations on the in vitro growth of O. varicosum plantlets. Murashige e Skoog culture medium was used modified with half concentration of the macronutrients. The plantlets, derived from seeds that were already established in vitro and 0.8 + 0.2 cm in height, were inoculated in the culture media containing the following carbohydrate sources: saccharine, maltose and glucose, at concentrations of 0, 10, 20, 30, 60 and 90 g.L-1. The following variables were analyzed 8 months later: canopy height, number of roots, greatest root length, pseudobulb diameter and fresh weight. A completely randomized block experimental design was used with five replications per treatment. Analysis of variance and the Tukey test (5%) were performed to compare the means. It was concluded that 60 g.L-1 saccharose was the best treatment for all the parameters assessed. The sugars 30 g.L-1 glucose and 60 g.L-1 maltose were also suitable, but presented lower pseudobulb diameter and lower fresh weight when compared to 60 g.L-1saccharose.O trabalho teve o objetivo de avaliar a influência do ácido indol-butírico sobre o enraizamento de estacas de acerola (Malpighia emarginata D. C.) na Universidade Estadual de Londrina. As plantas matrizes utilizadas pertencem a seleção Camb-6 do IAPAR, tiveram suas estacas colhidas com 10 a 12 cm de comprimento, com três a quatro pares de folhas e foram submetidas a uma imersão rápida (10 segundos) em soluções de ácido indol-butírico (AIB) com cinco concentrações (0, 500, 1.000, 1.500, 2.000 mg L-1). O delineamento estatístico adotado foi o de blocos ao acaso com cinco repetições, sendo cada parcela composta por 10 estacas. O ácido indol-butírico não influenciou o enraizamento das estacas, que apresentaram 36 a 46% de enraizamento.
Keywords