USDA-ARS Oat
Research, Raleigh, NC
We have begun freeze testing the Kanota/Ogle RILs to try and put QTL for freezing tolerance on the linkage map. However, the trait we measure will probably be more related to spring freezing since both Ogle and Kanota have become reproductive under the conditions we use to grow winter oats.
We have developed a technique to isolate tissue inside the crown that may be more related to freezing tolerance than the entire crown. Several experiments have shown significant differences in carbohydrate concentration between this tissue (meristem support tissue) and the stem tissue just above it. This is an ongoing study where we will look at changes in various biochemical processes during freezing. If there are differences between Wintok (hardy) and Fulghum (non-hardy) in the meristem support tissue then we will screen selected RILs of this cross to correlate the various traits to freezing tolerance.
We are continuing to test 4 freezing tolerant genotypes from a Wintok/Norline cross in the F8 generation. For 3 generations the genotypes have been significantly more freezing tolerant than either parent in controlled freeze tests. The cross was originally made by P. Murphy in 1993, and freezing tolerant individuals were selected in the F4 and F5 generations using controlled freezing. We hope to have enough seed to include the genotypes in the winter hardiness nursery for fall 2002.