Light and sucrose in micropropagation of Cattleya walkeriana: Anatomic and Physiologic changes / Luz e sacarose na microporapgação de Cattleya walkeriana: alteraçõies anatômicas e fisiológicas

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

Cattleya walkeriana ia a orchid of great decorative value. The use of micropropagation techniques are important issues in the reproduction of that specie. The use of conventional techniques of micropropagation causes plantlet losses during the acclimatization process and also promotes a high energy consumption in growth rooms which finishes by increasing the production costs. The objective of this work was to test some alternative micropropagation techniques. The plantlets were previously sprouted in vitro and grew for 90 days. In the first experiment were tested: light (in usual growth room GR; greenhouse shading 50% - GHS and greenhouse without shade GHWS) and different sucrose concentrations (0; 15,0 and 30 g L-1). Sunlight showed a higher number of lateral buds in GHWS, a large leaf thickness, increasead in the number and diameter of the stomata; resulted also in a decrease of the plantlets length and chlorophyll content. The total sucrose exclusion resulted in smaller chlorophyll content and death of cultivated plantlets in GHWS. The second experiment tested the effect of colored nets (red and blue) above the flasks cultivates in growth room or greenhouse (GH). GH-red gave a larger leaf thickness, higher stomata density, lower DP/DE relation and better acclimatization performance. GH-blue showed higher chlorophyll content ,more chloroplastid per cell, smaller stomata density and higher lateral buds number. In GR res and blue nets had practically the same performance on this environment, the light intensity was very low and its has a development damage of plantlets. With this results, we could say, that use of sunlight can be recommended with red and blue nets and sucrose concentrations reduction for C. walkeriana micropropagation. These procedures can reduce the production costs and increase the cultivated plantlets quality.

ASSUNTO(S)

micropropagation ciências agrárias ciências agrárias cultivo in vitro micropropagação orquídea orchid tissue culture

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