Evaluation of Polyethylene Glycol Test for Measuring Cell Membrane Stability in Maize

Cell membrane stability (CMS) of ten maize ( Zea mays L.) cultivars was measured by the polyethylene glycol (PEG) test and compared with other nutritional and physiological measurements to examine the nutriophysiological meanings of the test. Osmotic potential of leaf tissues was well correlated with CMS measured as percentage injury in the PEG test and it was suggested that it may have influenced on desiccation treatment in the PEG test. Leaf water potential, stomatal resistance and cuticular resistance did not show any correlation with CMS measured. Cultivars with high leaf water content were high in CMS and were tolerant to desiccation stress in the PEG test. They showed high excised-leaf water retention capability. Sugar, K. and Ca were the major solutes which contributed to osmotic potential. Potassium concentration in leaf tissues was well correlated with CMS, while sugar was not. It was suggested that K may play another role in increasing CMS in maize apart from its role as an osmotic substance.