EVALUATION AND IMPROVEMENT OF CEREAL GERMPLASM FOR DISEASE RESISTANCE AND WINTER-HARDINESS
Location: Plant Science Research
Title: Quantitative Trait Loci and Epistasis for Oat Winter Hardiness Component Traits
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 14, 2009
Publication Date: May 20, 2009
Citation: Wooten, D.R., Livingston, D.P., Lyerly, H.J., Holland, J.B., Jellen, E.N., Marshall, D.S., Murphy, J. 2009. Quantitative Trait Loci and Epistasis for Oat Winter Hardiness Component Traits. Crop Science. 48:149-157.
Interpretive Summary: In order to expand the area of adaptation of winter oats, improvements in winter hardiness and freeze tolerance in oats must be realized. An expanded area of adaptation would allow farmers to grow oats in more northern climates. Oats are a preferred grazing crop for domesticated livestock, so growing oats in more northern climates would be advantageous. The results of this research indicated that winter hardiness in oats was associated with two regions on oat chromosome 7 and that selection for winter hardiness could be done by selecting for the presence of those two regions. This finding will allow researchers to better and more efficiently select for oat winter hardiness in segregating populations, thereby potentially leading to improved winter hardiness in new oat varieties.
Winter hardiness is a complex trait and poor winter hardiness limits commercial production of winter oat (Avena species). The objective of this study was to identify Quantitative Trait Loci (QTL) for five winter hardiness component traits in a recombinant inbred line population derived from a cross between the winter-tender cultivar ‘Fulghum’ and the winter-hardy cultivar ‘Norline’. Crown freezing tolerance, vernalization response, and photoperiod response were evaluated in controlled environment studies. Heading date and plant height were evaluated over two seasons in Kinston, North Carolina, and winter field survival was evaluated in five environments over two seasons in the mountains of North Carolina and Virginia. A partial genetic linkage map of regions believed to affect winter hardiness was developed using RFLP and SSR markers. Most QTL were located on linkage groups FN3, FN22 and FN24.
QTL were identified for all traits except photoperiod response, and epistatic interactions were identified for winter field survival, crown freezing tolerance, vernalization response and plant height. Major QTL for winter field survival (R2=35%) and crown freezing tolerance (R2 =53%) were identified on linkage group FN3 which was associated with an intergenomic reciprocal translocation between chromosomes 7C and 17.