Organic Nutrients in the Media for Propagation of Cymbidium in vitro

Abstract

AbstractProtocorms of Cymbidium (Orchidaceae) were grown on media containing different organic nutrients. Of the sugars tested sucrose was better than maltose, glucose and fructose, and sucrose had an optimum concentration of 3 to 4 %. D‐Mannose was significantly less effective than the other sugars. The amino acid mixtures casamino acids (casein hydrolysate) and tryptone increased growth while yeast extract was inhibitory and malt extract without effect. Optimal concentrations were 2 to 3 g · l‐1 casamino acids and 3 to 4 g · l‐1 tryptone. It was to some extent possible to substitute the amino acid mixtures with a single amino acid (glutamine at 300 mg · l‐1). Arginine was inhibitory and asparagine was without any effect. Vitamins proved to be unnecessary although there was a tendency towards increased growth with nicotinic acid and meso‐inositol. Purines and pyrimidines were added to the medium but with no effect. Liquid endosperm from coconuts (10 to 15%) increased growth while the liquid endosperm from Aesculus hippocastanum was inhibitory. On the basis of these results a revised medium is proposed for the in vitro propagation of Cymbidium.