|Wooten, David - MONSANTO|
|Murphy, J Paul - NORTH CAROLINA STATE UNIV|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 10, 2007
Publication Date: January 15, 2008
Citation: Wooten, D., Livingston, D.P., Holland, J.B., Marshall, D.S., Murphy, J. 2008. Quantitative trait loci and epistasis for crown freezing tolerance in the Kanota x Ogle hexaploid oat mapping population.. Crop Science. 48:149-157. Interpretive Summary: Correlating specific pieces of DNA with freezing tolerance is one way to identify freezing tolerant plants without freeze testing them. These pieces of DNA related to freezing tolerance are called quantitative trait loci (QTL). In this study a winter and sprint oat were crossed and 135 of their projeny were freeze tested and analyzed for QTL that were related to freezing. Seven QTL and 4 genes that interact with each other were identified in this group of plants that explanes up to 56% of the freezing tolerance that was observed in the population. This suggests that it may be possible to find freezing tolerant individuals in juvenile plants without having to freeze test them and may help breeders select new freezing tolerant cultivars.
Technical Abstract: Winter hardiness is a complex trait, and poor winter hardiness limits commercial production of winter oat. Crown freeze tolerance is the most important factor conferring winter hardiness, and controlled crown freeze tests correlate well with field winter hardiness. The objective of this study was to identify quantitative trait loci for crown freeze tolerance in the Kanota × Ogle recombinant inbred line (RIL) mapping population and to examine their relationship with other winter hardiness component traits. One hundred thirty five RILs were evaluated for crown freeze tolerance in a controlled environment. Previously published molecular marker and linkage map information was used for crown freeze tolerance QTL detection. Seven QTL and four complimentary epistatic interactions were identified that accounted for 56% of the phenotypic variation. Ogle contributed alleles for increased crown freeze tolerance at three loci, while Kanota contributed alleles for increased crown freeze tolerance at four loci. All loci where Kanota alleles increased crown freeze tolerance showed complementary epistasis for decreased crown freeze tolerance with the QTL near UMN13. Two of the major QTL identified were in the linkage groups associated with a reciprocal translocation between chromosomes 7C and 17 which previously was associated with spring growth habit in oat. The results confirm the importance of the chromosomes involved in the reciprocal 7C-17 translocation in winter hardiness component traits.