METHOD: Ion Leakage CONDITIONS: Green House - 14h light at 20C METHOD NARR: Ten-week-old plants were divided into one of two groups. One group was used to measure frost tolerance without cold acclimation. The other group was moh light at 2C) for 2 weeks. Freezing injury was estimated by the ion leakage method. LT50 is the temperature at which 50% of the cells were killed. A cross was made and progeny were tested similarly. RESULTS NARR: There0 between nonacclimated and acclimated plants of a particular genotype, and also between individual genotypes. AUTHOR EXPLANATION: These results support the conclusions that frost hardiness and cold acclimation potential areontrol of relatively few genes. An additive-dominance model adequately explains the gene action of frost hardiness and cold acclimation. This study used LT50 as a measure while others have used acclimation capacity. These quantities