Figure 1.

Freezing survival of seedlings of B. stricta SAD12 (from Colorado) and LTM (from Idaho) ecotypes. Non-acclimated (A) and cold acclimated plants (B) were subjected to a range of subzero temperatures, and survival was scored after thawing. Fitted response curves were used for calculation of LT50, the temperature at which 50% of the plants died. Significant differences (P < 0.01, Student’s t test) are indicated by asterisks. Data represent means (±sd) of five agar plates containing 30 seedlings each.