Humidity in plant tissue culture vessels

The relative humidity within the culture vessels is usually very high, resulting in poorly developed epicuticular wax layer and malfunctioning stomata of the plantlets. In this study, the humidity profile in the plant culture vessel was measured by the high polymer humidity sensor. The accuracy of these sensors was improved by calibration equations established using several saturated salt solutions. The tension of the medium was measured by a piezoresistive silicon tension meter. A vapour transfer model was proposed to describe the factors affecting relative humidity in the vessel. The evaporation model of the medium was established to quantify these factors. Several techniques that had been applied for reducing the relative humidity were evaluated by the vapour transfer model. (C) 2004 Silsoe Research Institute. All rights reserved Published by Elsevier Ltd.