Introduction
Winter wheat accounts for about 4 % of the total wheat area cultivated
in Canada. The low acreage of winter wheat cultivation is mainly due to
unreliable winter survival. However, with proper crop rotation and agronomic
management systems winter wheat has been suggested to be more productive
and profitable. There are several other advantages of growing winter wheat
(http://www.eap.mcgill.ca/CPW_8.htm). For example, during the fall and
winter it provides soil cover, thereby reducing soil erosion. It has the
ability to use early spring soil moisture more efficiently than spring
cereals, matures earlier than spring wheat and yield-wise, may be 10-15
% higher. Winter wheat is known to be extremely capable of recovering
from winter damage and that even if 50 % of the plants are killed, the
yield potential would have only decreased by 10 %, had there been no kill.
With all the benefits associated with winter wheat, breeders are continually trying to further improve its quality and its tolerance to extreme cold in order to entice farmers into including winter wheat cultivation into their cropping systems. The currently available winter wheat varieties have a range of cold-tolerance (LT50 values ranging from about -10 to -24 oC). LT50 values refer to the temperature at which 50 % of the plants are killed due to low temperature. This tolerance of winter wheat to cold is a complex process and involves a process known as cold acclimation, wherein it acquires tolerance to cold over the fall growing period, due to the gradual decrease in temperature during that period. Many genes are induced or repressed during this cold acclimation process contributing directly or indirectly to the hardiness of the winter wheat plant.
Plant breeders as well as molecular biologists are only beginning to gain an insight into this complex process and are attempting to dissect out the underlying pathways in order to enhance the cold tolerance of winter wheat. In this study techniques based of DNA fingerprinting such as Random Amplified Polymorphic DNA (RAPD) (Williams et al., 1990), Amplified Fragment Length Polymorphism (AFLP) (Vos et al., 1995) and RNA fingerprinting (cDNA-AFLP) (Bachem et al. 1996) will be used for transcript profiling. cDNA-AFLP is a well-established procedure for transcript profiling. However, alternative methods that are expeditious and cost-effective would also be of value in research and worth exploring.