ARS | Publication request: HIGH RESOLUTION MAPPING ADJACENT TO THE PC71 CROWN-RUST RESISTANCE LOCUS INHEXAPLOID OAT

Submitted to: Molecular Breeding
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 10, 1997
Publication Date: N/A

Interpretive Summary: Crown rust is a major fungal disease of cultivated oat. Breeding for resistance to this disease can be difficult, due to complex interactions between the oat plant and the crown rust fungus. The identification of DNA markers associated with crown rust-resistance can be used to assist breeders in developing resistant lines. Additionally, markers closely linked to a resistance gene are an important component of the effort to clone resistance genes, which will help increase our understanding of the mechanisms of disease resistance in general, and for crown rust resistance specifically. In this study, we have identified DNA markers very close to Pc7l, a gene conferring resistance to crown rust isolate 345. These markers will be used to further our studies on resistance to crown rust and aid in breeding resistant lines.

Technical Abstract: The D526-derived BC1F2 population of hexaploid oat segregates for resistance to crown rust isolate 345. A mapping population consisting of 440 F2 individuals was used to develop a high resolution RFLP map of the area of the genome where Pc7l, the locus conferring this resistance, is located. Twelve RFLP markers have been identified within approximately 6 cM of Pc7l, with Xcdol502 and Xcdo783 cosegregating 0.2 cM from the locus. All of the RFLP markers map to the same side of the locus, suggesting either that the Pc7l resistance locus resides at the end of a linkage group, or that there is no detectable heterozygosity on the flanking side.