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ARS Home » Midwest Area » Ames, Iowa » Corn Insects and Crop Genetics Research » Research » Publications at this Location » Publication #88360

Title: DISSECTING A RESISTANCE LOCUS WITH MULTIPLE SPECIFICITIES TO <I>PUCCINIA CORONATA</I> AND ESTABLISHING A SATURATED AFLP MAP IN DIPLOID <I>AVENA</I>

Author
item XIN, YU
item Wise, Roger

Submitted to: Plant and Animal Genome Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 11/18/1997
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Puccinia coronata Cordaf. sp. avenae Eriks., the causal agent of crown rust, is the most important fungal pathogen of cultivated oat. The Pca crown-rust resistance-gene cluster was identified by analyzing a diploid Avena recombinant inbred (R1) population generated by crossing the crown-rust resistant A. strigosa accession nC.I. 3815 with the susceptible A. wiestii accession C.I. 1994. To further determine the composition of the Pca locus, we analyzed seven F2 backcross (BC1F2) populations between the susceptible parent C.I. 1994 and seven key R1 lines with putative recombination break points. These BC1F2 populations were tested with diagnostic crown-rust isolates. As a result of these analyses, multiple specificities of the Pca locus were demonstrated to be controlled by a series of closely linked genes within the Pca cluster. A saturated AFLP map was constructed for diploid Avena and three AFLP markers were found to be closely linked to the Pca cluster. Allele-specific PCR primers were designed for the Agx4 marker that co-segregated with the R202 specificity within Pca. The Agx4 PCR primers will be valuable to study the evolution of the Pca cluster and in the marker-assisted breeding of Avena.