Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: May 9, 2005
Publication Date: November 6, 2005
Citation: Skinner, D.Z., Garland Campbell, K.A. 2005. Distributions of cold tolerance in f3 wheat populations. ASA-CSSA-SSSA Annual Meeting Abstracts, Nov 6-10, Salt Lake City, UT. 240:15. Technical Abstract: The temperatures at which 50% of fully acclimated plants are killed (LT50) were determined as -13.6C, -13.5C, and -9.5C, for cultivars ‘El Tan,' ‘Tiber,' and ‘Oregon Feed Wheat #5 (ORFW),' respectively. Thirty-one F2:3 populations from the cross of El Tan X ORFW (E X O) and 31 from Tiber X ORFW (T X O) were acclimated and tested for ability to survive exposure to -12C soil temperature for one hour. The mean percentage survival for the two crosses were virtually identical. However, the mean survival of the T X O F3 populations was less than the midparent while the mean survival of the E X O F3 populations was greater than the midparent. Density plots of the F3 survival percentages showed a bimodal distribution in both crosses with modes at about 10% survival and at 60-80% survival. The density plot of the composite data showed a trimodal distribution, reflecting differences in the two populations. These density plot results suggest polygenic inheritance of response to freezing with the majority of gene combinations conferring very little (ca. 10%) survival, but a slight propensity in favor of 60-80% survival as opposed to 40-50% survival. These results suggest different sets of genes are responsible for cold tolerance in ‘Tiber' compared to ‘El Tan,' even though the standard LT50 test results in virtually identical scores.