Effect of sealed and vented gaseous microenvironments on the hyperhydricity of potato shoots in vitro

Abstract

Different types of ventilation of the culture vessel with and without the ethylene inhibitor KMnO4 in the culture media were investigated in terms of their effect on hyperhydricity of in vitro cultured potato shoots. The shoots grown in a completely sealed vessel (CSV) were severely vitrified, but the shoots cultured in a gas permeable vessel (GPV) showed normal shoot proliferation. Dry weight percentage and chlorophyll content were lower in the vitrified shoots than in the normal shoots. The levels of ethylene and CO 2 were significantly higher in the CSV, but little ethylene was detected in the GPV system. When an ethylene scrubber (perlite treated with KMnO4) was applied to the CSV, the shoots exhibited normal growth without any sign of vitrification. In addition, no ethylene was found in CSV with the ethylene scrubber (CSVE). These results indicate that hyperhydricity is related to the ethylene accumulated in the culture vessel during the in vitro culture of potato shoots. It is suggested to use CSVE to reduce the ethylene level and overcome hyperhydricity.