Submitted to: Agronomy Society of America, Crop Science Society of America, Soil Science Society of America Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 10/1/2008
Publication Date: 10/6/2008
Citation: Skinner, D.Z. 2008. Logistic Regression Analysis of the Response of Winter Wheat to Components of Artificial Freezing Episodes. ASA/CSSA/SSSA Annual Meeting, Houston, TX. paper 44308. Interpretive Summary: This is an abstract of a presentation made at the annual meeting of the Crop Science Society of America. The report detailed a method of discerning what portions of the freezing process were most injurious to wheat cultivars. It was found that different cultivars may be more sensitive to different parts of the freezing process than others. This is significant because it suggests it is possible to combine abilities to tolerate parts of the freezing process into one wheat line, thereby making a more freezing tolerant wheat.
Technical Abstract: Improvement of cold tolerance of winter wheat (Triticum aestivum L.) through breeding methods has been problematic. A better understanding of how individual wheat cultivars respond to components of the freezing process may provide new information that can be used to develop more cold tolerance cultivars. Data are presented indicating how various components of the freezing process impacted survival of the cultivars Eltan, Froid, Kestrel and Tiber. Response surface analysis and logistic regression equations suggested that cultivars Eltan and Froid used different mechanisms of responding to freezing stress than did Kestrel and Tiber. While Kestrel and Tiber appeared to use essentially the same mechanisms, plots of logistic regression analysis residuals suggested that Kestrel survived harsh freezing more efficiently that Tiber, but Tiber survived less harsh freezing that Kestrel. Two F2- derived F4 lines selected from the cross of Kestrel and Tiber were significantly more cold tolerant than Kestrel, the more hardy parent, under harsh freezing conditions. Analyzing the response of wheat cultivars to components of the freezing process provides clues as to which cultivars may use different mechanisms in responding to freezing stress. Developing logistic regression equations and examining their predictive capability in different populations appearing to use primarily the same mechanism provides evidence of differences in effectiveness of that mechanism in different genotypes. Hybridization of wheat lines using primarily the same mechanism but with differing effectiveness may result in the recovery of favorable allele combinations leading to enhanced freezing stress tolerance.