Effect of cold-acclimation on freezing tolerance in canola (Brassica napus L.)

Of the many factors influencing winter survival of plants, freezing tolerance is one of the most important. This study was conducted to determine the relationship between in vitro freezing tolerance and winter survival of canola (Brassica napusL.). Six winter cultivars and one spring cultivar that had previously exhibited a broad range of winter survival were examined both in a controlled environment chamber and under field conditions. Freezing tests showed that cold acclimation increased the freezing tolerance of both winter and spring cultivars, and that the differences in freezing tolerance among cultivars were due to their ability to acclimate. Freezing tolerance measured by electroleakage tests was highly correlated with winter survival. This suggests that the electroleakage test can be used to predict the comparative winter survival of canola cultivars and tools for the selection of winter hardy cultivars in plant breeding.