Theoretical and Applied Genetics (2010) 120, 573-585

Vance M. Whitaker, James M. Bradeen, Thomas Debener, Anja Biber and Stan C. Hokanson (2010)
Rdr3, a novel locus conferring black spot disease resistance in tetraploid rose: genetic analysis, LRR profiling, and SCAR marker development
Theoretical and Applied Genetics 120 (3), 573-585
Abstract: Black spot disease of rose, incited by the fungus Diplocarpon rosae, is found worldwide and is the most important disease of garden roses. A gene-for-gene interaction in this pathosystem is evidenced by the presence of pathogenic races of D. rosae and the previous discovery of a dominant resistance allele at the Rdr1 locus in the diploid Rosa multiflora. The objective of the present study was to genetically analyze resistances to North American black spot races 3, 8, and 9 previously reported in tetraploid roses. Resistance to North American races 3 and 8 segregated 1:1 in multiple F₁ populations, indicating that both are conferred by dominant alleles at single loci and are present in simplex (Rrrr) configuration. Gene pyramiding was demonstrated by combining both resistances into single genotypes. Resistance to race 9 was partial and segregated in a quantitative fashion. Analysis of these populations with microsatellite markers previously developed for Rdr1 revealed that the gene conferring race 3 resistance resides within the same R gene cluster as Rdr1. Race 8 resistance segregated independently and is, therefore, a novel locus for black spot resistance in rose which we have named Rdr3. NBS and LRR profiling were used in a bulked segregant analysis to identify a marker 9.1 cM from Rdr3, which was converted to a SCAR marker form for marker-assisted breeding.
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Link to article at publishers website
Database assignments for author(s): Thomas Debener, James M. Bradeen

Research topic(s) for pests/diseases/weeds:
resistance/tolerance/defence of host

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Diplocarpon rosae	Rosa (crop)