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ARS Home » Pacific West Area » Aberdeen, Idaho » Small Grains and Potato Germplasm Research » Research » Publications at this Location » Publication #175494
Title: CHARACTERIZATION AND MAPPING OF A CROWN RUST RESISTANCE COMPLEX (PC-58) IN TAM 0-301.

Author
item Hoffman, David
item CHONG, JAMES - AG&AGRI-FOOD CANADA, MB
item Jackson, Eric
item Obert, Donald

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/1/2006
Publication Date: 11/1/2006
Citation: Hoffman, D.L. (deceased), Chong, J., Jackson, E.W., Obert, D.E. 2006. Characterization and mapping of a crown rust resistance complex (pc-58) in tam 0-301.. Crop Science. 46:2630-2635

Interpretive Summary: Crown rust is a devastating disease of oat, a multi-purpose cereal grain with unique quality characteristics such as high concentrations of a well-balanced protein and oil with saturated fatty acids, and health-related compounds such as beta-glucan and many antioxidants. Crown rust impacts forage and grain yield and the quality of both. The best way to control the disease has been genetic resistance derived from wild oat relatives. For efficient use of the resistance genes, it is important that scientists understand the genetic basis of the resistance. This has been done for many crown rust resistance genes, but not for Pc58. The purpose of this study was to use a mapping population to expand our knowledge of the genetics of Pc58. We found that Pc58 is not one gene, but a complex of three genes which link to each other and to two linkage groups of the Ogle x TAM O-301 linkage map. Genetic tags were proposed for two of the rust resistance genes, but more work is needed to identify a tag for the third resistance gene. This study extended our knowledge of the genetics underlying Pc58, a useful gene for crown rust resistance in eastern North America. Scientists can use this information to refine the genetic tags foand stack Pc58 resistance with other crown rust resistance genes for more durably crown rust resistant oat varieties with less compromised yield and quality.

Technical Abstract: Crown rust of cultivated oat (Avena sativa L.) caused by Puccinia coronata f.sp. avenae causes yield losses, reductions in test weight, and increased lodging, when susceptible varieties are grown. Genetic resistance is the most desirable method to control the disease. ‘TAM O-301’, a cultivar released by the Texas A&M oat-breeding program in the 1970s, has effective crown rust resistance, subsequently named Pc-58. The main objectives of this study were to Characterize Pc-58 in TAM-0-301 using a F6:7 recombinant inbred lines, and to map the Pc-58 resistance. Six crown rust races, avirulent on ‘TAM O-301’ and virulent on ‘Ogle’ were used to screen the parents and RI population.. Genetic analyses of the segregation data to each of the six races indicated that the resistance wasconditioned by three linked resistance genes within a 35.6 cM region. The resistance genes were linked to and combined linkage groups, OT 32 and OT 33 in the published molecular linkage map of Ogle x TAM O-301. Since current markers are not PCR-based in nature and flanking genetic markers are not closely linked to each candidate gene development of new marks should be done. This research has provided new information on the Pc58 resistance gene complex that should facilitate new marker and germplasm development.