Rdr3, a novel locus conferring black spot disease resistance in tetraploid rose: genetic analysis, LRR profiling, and SCAR marker development.
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 F(1) 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.
Department of Horticultural Science, Gulf Coast Research and Education Center, University of Florida, 14625 CR 672, Wimauma, FL 33598, USA. vwhitaker@ufl.edu
Vance M
VM
Whitaker
James M
JM
Bradeen
Thomas
T
Debener
Anja
A
Biber
Stan C
SC
Hokanson
D001203:Ascomycota / Q000502:physiology; D001665:Binding Sites; D020090:Chromosome Segregation / Q000235:genetics; D003433:Crosses, Genetic; D056426:Genetic Loci / Q000235:genetics*; D005819:Genetic Markers; D007113:Immunity, Innate / Q000235:genetics / Q000276:immunology*; D000090263:Leucine-Rich Repeat Proteins; D018895:Microsatellite Repeats / Q000235:genetics; D009656:North America; D009711:Nucleotides / Q000378:metabolism; D010641:Phenotype; D010935:Plant Diseases / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D011110:Polymorphism, Genetic; D011123:Polyploidy; D011506:Proteins / Q000378:metabolism*; D027826:Rosa / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D036226:Seedlings / Q000235:genetics / Q000276:immunology / Q000382:microbiology; D012689:Sequence Homology, Nucleic Acid
D005819:Genetic Markers; D000090263:Leucine-Rich Repeat Proteins; D009711:Nucleotides; D011506:Proteins