Regulation of in vitro bud formation of date palm (Phoenix dactylifera L.) cv. Khanezi by different carbon sources

The influence of different carbon sources and concentrations on in vitro shoot multiplication of date palm cv. Khanezi were investigated. Sucrose, glucose, fructose and maltose sugars were used at the following concentrations; 0, 30, 60, 90 and 120 g l(-1). Shoot dry weight was significantly increased with increasing sugar concentrations while little growth was obtained in the absence of sugar. Concentrations of 30 and 60 g l(-1) were optimal for qualitative and quantitative shoot growth while abnormal growth was observed at 90 and 120 g l(-1) possibly due to osmotic stress. Sugar type had significant effects on most parameters measured except bud formation. Fructose produced the highest values of dry weights compared with other carbon sources. In addition, glucose, fructose and maltose were almost equivalently effective as a carbon source for culture of date palm compared with sucrose. It is also noticed in this study that the root formation was enhanced as the sugar concentration increased (60 g l(-1) and above). This rooting of buds generally reduced their ability to multiply during multiplication stage and occasionally inhibited bud formation especially in higher concentration of sugar. (c) 2007 Elsevier Ltd. All rights reserved.