Fig. 2.

Regrowth biomass of two red clover cultivars under recurrent selection after exposure to freezing temperature. Regrowth dry matter (g plant⁻¹) was measured three weeks after exposure to a −13 °C freezing stress in the initial genetic backgrounds (TF0) and populations obtained after three (TF3) and four (TF4) cycles of recurrent selection for superior freezing tolerance. Plants were previously acclimated in an unheated greenhouse during fall and winter 2010-2011. Each value is the averaged regrowth of 200 plants. Different letters represent significant differences at P < 0.05 and error bars represent Standard Errors