Identification of non-TIR-NBS-LRR markers linked to the Pl5/ Pl8 locus for resistance to downy mildew in sunflower.
The resistance of sunflower, Helianthus annuus L., to downy mildew, caused by Plasmopara halstedii, is conferred by major genes denoted by Pl. Using degenerate and specific primers, 16 different resistance gene analogs (RGAs) have been cloned and sequenced. Sequence comparison and Southern-blot analysis distinguished six classes of RGA. Two of these classes correspond to TIR-NBS-LRR sequences while the remaining four classes correspond to the non-TIR-NBS-LRR type of resistance genes. The genetic mapping of these RGAs on two segregating F2 populations showed that the non-TIR-NBS-LRR RGAs are clustered and linked to the Pl5/ Pl8 locus for resistance to downy mildew in sunflower. These and other results indicate that different Pl loci conferring resistance to the same pathogen races may contain different sequences.
UMR 1095 INRA-UBP "Amélioration et Santé des Plantes", Université Blaise Pascal, 24, Avenue des Landais 63177 Aubiére Cedex, France.
O
O
Radwan
M F
MF
Bouzidi
F
F
Vear
J
J
Philippon
D Tourvieille
DT
De Labrouhe
P
P
Nicolas
S
S
Mouzeyar
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D017931:DNA Primers; D008040:Genetic Linkage; D005819:Genetic Markers; D005838:Genotype; D006368:Helianthus / Q000235:genetics* / Q000382:microbiology; D008969:Molecular Sequence Data; D005810:Multigene Family; D009868:Oomycetes / Q000472:pathogenicity*; D010940:Plant Proteins / Q000235:genetics*; D017386:Sequence Homology, Amino Acid
D017931:DNA Primers; D005819:Genetic Markers; D010940:Plant Proteins