EVALUATION AND IMPROVEMENT OF CEREAL GERMPLASM FOR DISEASE RESISTANCE AND WINTER-HARDINESS
Location: Plant Science Research
Title: New Advances in Marker Assisted Selection for Winter Hardiness in Oats.
Submitted to: American Oat Workers Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: April 17, 2010
Publication Date: April 18, 2010
Citation: Maloney, P., Lyerly, J., Wooten, D., Anderson, J.A., Livingston, D.P., Brown Guedira, G.L., Marshall, D.S., Murphy, P. 2010. New Advances in Marker Assisted Selection for Winter Hardiness in Oats.. American Oat Workers Conference Proceedings.
Interpretive Summary: Crown freezing tolerance has one of the largest effects on winter field survival. Marker loci AM102, HVM20, JAO4636, AM114, JAO4234, and xncs15-3, were found linked to QTL of interest for winter hardiness component traits in the biparental population and were significantly associated with increased crown freezing tolerance in the association study. A potential source of crown freezing tolerance in ancestral germplasm was identified using genotypic data from the AM population. At least one of the nine crown freezing tolerance associated alleles were found in all 63 lines tested. Winter Turf contained associated alleles at five of the nine critical marker loci and Fulghum contained associated alleles at seven of the nine critical marker loci. These two progenitors appeared in the pedigrees of the top 15 winter hardy lines tested, except for ‘Cliff’. Nevertheless, Cliff still contained alleles at four of the nine associated marker loci. By using linkage analysis alone, marker assisted selection for the significant QTL is very difficult to justify. However when the results of the linkage analysis are paired with the results of an AM study, where the significant loci are tested across a larger genetic base, allele use in MAS programs is of greater importance. It is a safe conclusion that AM102-220bp, HVM20-143bp, JAO4636-277bp, and AM114-260bp would be informative markers for crown freezing tolerance in a MAS program.
Oat (Avena sativa L.) breeding and genetics research has lagged behind other small grains, such as wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.), in the development of PCR based markers and map construction due to fewer oat researchers and reduced research funding. As a result, marker assisted selection has not become a routine procedure in oat cultivar development. However, with new studies in mapping populations, marker development, and QTL identification, oat is gaining momentum in the research sector.A major issue that plagues fall sown oat is the poor ability to tolerate freezing temperatures. Fall sown oat has the poorest winter hardiness among all small grains cereals. Winter hardiness, or a plant’s ability to stay healthy and dormant during the winter period, is a very complex trait that brings together many different components from photoperiod to crown freezing tolerance. A recent study developed a linkage map using two fall sown oat parents and located QTL for winter hardiness component traits. The objectives of this project were to i) increase the number of SSR markers on the Fulghum x Norline recombinant inbred population (RIP) genetic map, and to scan for QTL associated with winter hardiness component traits, including winter field survival, crown freezing tolerance, vernalization response, and heading date, and ii) utilize an association mapping (AM) population to validate markers of interest from the Fulghum x Norline population that are most closely linked to the winter hardiness component traits specifically crown freezing tolerance and trace the origin of the crown freezing tolerance alleles to a specific ancestral cultivar(s) in the United States cultivated oat gene pool.