METHOD: Ion Leakage CONDITIONS: Green House - 14h light at 18-24C METHOD NARR: Frost tolerance was tested using the electrolyte leakage test of Sukumaran & Weiser, 1972. Sixty days after transplanting, fully expanded terminal le1C per hour from -2C to -6C. LT50 values were determined. Stomatal indenx was also determined. Tbr x cmm hybrids were also examined. RESULTS NARR: The estimated LT50 of cmm is -5.3 and tbr is 1.2. Hybrids were more rese were very close to the cmm parent. The stomatal index of the upper leaf surface of cmm was 13% and tbr was 6%. AUTHOR EXPLANATION: The stomatal index is said to be correlated with frost hardiness, but such a correlation waanalyzed.