Fig. 1

Freezing tolerance of recurrently selected populations of red clover cultivars in response to cold acclimation. Freezing tolerance is expressed as the lethal temperature for 50 % of plants (LT₅₀) of the original background (TF0) and populations obtained after three (TF3) and four (TF4) cycles of recurrent selection within two cultivars of red clover: Christie and Endure. Measurements were taken with non-acclimated plants in October and cold-acclimated plants in January and February. Only plants of the initial backgrounds (TF0) and populations TF4 were assessed in the non-acclimated state. Different letters represent significant differences at P < 0.05 and error bars represent Standard Errors