ARS | Publication request: Linkage Disequilibrium Among Two Lolium Perenne CBF Genes and Association With Freezing Susceptibility

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: January 9, 2010
Publication Date: January 11, 2010
Citation: Bushman, B.S., Hulke, B.S., Ehlke, N. 2010. Linkage Disequilibrium Among Two Lolium Perenne CBF Genes and Association With Freezing Susceptibility. Plant and Animal Genome Conference, San Diego, CA. Meeting Abstract.

Technical Abstract: Perennial ryegrass(Lolium perenne) is one of the most abundantly utilized forage and turfgrass species; however, its lack of tolerance to freezing temperatures relative to other forage/turf grasses limits its use. A pseudo-testcross genetic mapping population was previously developed for perennial ryegrass, and a major QTL was found for frost tolerance on linkage group 5. That region corresponded to the Fr-2 freezing tolerance locus in cereals and within that region a cluster of C-repeat binding factor (CBF) genes mapped. In this study, we selected 108 perennial ryegrass plants distributed around the world, and lacking live endophytes, for an association test of CBF3 gene effects on freezing tolerance. DNA was extracted from each plant, and then each plant was tested for freezing tolerance in a growth chamber. Two CBF3 paralogs were sequenced, and associations were detected for weaker, not stronger, alleles in CBF3c. Linkage disequilibrium extended throughout CBF3b, but not CBF3c. A frame shifting INDEL was detected in a number of plants in both CBF3b and 3c genes, but did not correlate with freezing tolerance.