Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 13, 2012
Publication Date: September 1, 2012
Citation: Hulke, B.S., Bushman, B.S., Watkins, E., Ehlke, N.J. 2012. Association of freezing tolerance to LpCBFIIIb and LpCBFIIIc gene polymorphism in perennial ryegrass accessions. Crop Science. 52:2023-2029. Interpretive Summary: Lolium perenne L. or perennial ryegrass, is an important turfgrass and forage grass around the world. It is also a seed production crop in the USA. Its value is diminished by its lack of winterhardiness in colder regions, where it is susceptible to winterkill. In this study, we attempted to find whether or not a gene family that has been important for cold tolerance in other crops such as barley, may have an effect on cold tolerance in perennial ryegrass. An association mapping population was assembled, screened for freezing tolerance in the laboratory, and sequenced completely at two CBF/DREB genes. The result was the discovery of one major mutation leading to changes in freezing tolerance, and several minor mutations that appear to also affect freezing tolerance.
Technical Abstract: CBF/DREB related genes are considered important genes for regulation of abiotic stress in plants. In this study, CBF/DREB genes in perennial ryegrass (Lolium perenne L.), also known as LpCBF genes, were resequenced from several cultivated and landrace plants from a worldwide collection. The same plants were subjected to freezing tolerance testing and the data subjected to mixed model analysis to determine whether the freezing tolerance is related to SNP and indel markers of two genes, LpCBFIIIb and LpCBFIIIc. One major QTL was discovered in LpCBFIIIc for freezing tolerance. Several minor QTL were also discovered for freezing tolerance and cloning tolerance, a different abiotic stress.