METHOD: Inheritance CONDITIONS: Biotron - 14h light at 18-20C and 70% RH or 2-4C METHOD NARR: Freezing tolerance was determined by gradually lowering the temperature of a cooling bath and submerging tubes containing excised leaflwas assessed by measurement of ion leakage. Relative freezing tolerance was determined from the midpoint of the maximum and minimum ion leakage vales obtained for each genotype. RESULTS NARR: The mean nonacclimated RFT ofto that of the cph parent than that of the cmm parent. Similarly, acclimation capacity of the F1 population was closer to that of the cph parent. These two traits were not significantly correlated , suggesting independent genes. Additive-dominance is adequate to explain acclimation capacity but not nonacclimated freezing tolerance. AUTHOR EXPLANATION: The distributions of the backcross progenies support the conclusion that nonacclimated freezing toleranapacity are controlled by relatively few genes, since backcross distributions show near recovery of parental phenotypes for nonacclimated freezing tolerance and full recovery for acclimation capacity. During active growtht survival depends on the nonacc. freezing tolerance. During cold acclimation conditions in fall, growth usually slows and the plant goes in to dormancy.