Influence of hydrolized casein on the Oncidium baueri (Orchidaceae) in vitro cultivation

摘要

The nitrogen is essentially important for most in vitro cultivated species. It is regarded to the physiological and biochemical processes involved in growth control, differentiation and morphogenesis, and casein is one of the main nitrogen supplementation sources. The objective of this work was to evaluate the influence of different concentrations of hydrolized casein on the in vitro vegetative growth and rooting of Oncidium baueri (Orchidaceae). The treatments tested were: T1 - 0.0 g.L-1; T2 - 0.5 g.L-1; T3 - 1.0 g. L-1; T4 - 2.0 g.L-1; T5 - 4.0 g.L-1 of hydrolized casein. The culture medium used was the Murashige and Skoog modified with half macronutrients concentration. Total fresh mass, aerial part height, biggest root length, roots number and lateral sprouts number were evaluated after six months from the beginning of the experiment. It was not detected any beneficial effects of casein on vegetative and root development of Oncidium baueri. The percentage of surviving plants was 100%, 95% and 94%, respectively for T1, T2 and T3, and 80% of surviving plants for T4 and T5.