P0304 Different Haplotypes of TaCBF-A12 Are Associated With Freezing Tolerance in Hexaploid Wheat

Jie Zhu , Washington State University, Pullman, WA
Adrienne Burke , USDA-ARS, Pullman, WA
Carl A. Walker , Washington State University, Pullman, WA
Stephen Pearce , University of California, Davis
Daniel Z. Skinner , USDA-ARS, Pullman, WA
Kimberly Garland Campbell , USDA-ARS, Pullman, WA
Extremely low temperatures in winter can cause severe damage to winter wheat. Breeding of freeze-tolerant winter wheat is an urgent task in the face of an increasingly variable world climate. The C-repeat Binding Factor(CBF) genes TmCBF12, TmCBF14 and TmCBF15 were hypothesized to play critical roles in freezeing tolerance of T. monococcum. Orthologs of TaCBF12, TaCBF14 and TaCBF15 in the A, B, and D genomes of hexaploid wheat (T. aestivum) were sequenced within a diverse panel of 70 cultivated winter wheats collected from different parts of the world, in order to exploit haplotypes of these nine genes, if associated with freezing tolerance. One indel polymorphism and three SNPs(single nucleotide polymorphisms) in TaCBF-A12 and one in-del polymorphism and five SNPs in TaCBF-A15 were found in the diverse panel. An F2-derived F3 population of 58 individuals from winter wheat populations ‘OFW#5’/‘Eltan’ ‘OFW#5’ /‘Tiber’, was used to test the association between TaCBF-A12 haplotypes and survival in artificial freezing trials. A significant association (P<0.1) was found between the polymorphisms mentioned above and survival.  In addition, two alleles of Vrn-A1, Vrn-A1v and Vrn-A1w, which are distinguishable by a single-nucleotide polymorphism (SNP) in exon 4, were segregating in these populations but were found to be not significantly associated with freezing tolerance. Larger winter wheat populations are currently being evaluated for associations between freezing tolerance and polymorphisms at the TaCBF-A12, TaCBF-A15 and at Vrn-A1 loci.