High-resolution genetic mapping of the leaf stripe resistance gene Rdg2a in barley.
The dominant gene Rdg2a of barley conferring resistance to the hemi-biotrophic seed-borne pathogen Pyrenophora graminea is located in the distal region of chromosome arm 1 (7H)S. As the first step towards isolating the gene, a high-resolution genetic map of the region was constructed using an F(2) population of 1,400 plants (Thibaut Rdg2axMirco). The map included six classes of resistance gene analogues (RGAs) tightly associated with Rdg2a. Rdg2a was delimited to a genetic interval of 0.14 cM between the RGAs ssCH4 and MWG851. Additional markers were generated using the sequence from the corresponding region on rice chromosome 6, allowing delimitation of the Rdg2a syntenic interval in rice to a 115 kbp stretch of sequence. Analysis of the rice sequence failed to reveal any genes with similarity to characterized resistance genes. Therefore, either the rice-barley synteny is disrupted in this region, or Rdg2a encodes a novel type of resistance protein.
Bulgarelli
D
D
Istituto sperimentale per la Cerealicoltura, Sezione di Fiorenzuola d'Arda, Via S. Protaso 302, 29017 Fiorenzuola d'Arda, Italy.
Collins
N C
NC
Tacconi
G
G
Dellaglio
E
E
Brueggeman
R
R
Kleinhofs
A
A
Stanca
A M
AM
Valè
G
G
D001203:Ascomycota / Q000276:immunology; D002874:Chromosome Mapping; D003433:Crosses, Genetic; D017931:DNA Primers; D017343:Genes, Plant / Q000235:genetics*; D005819:Genetic Markers; D001467:Hordeum / Q000235:genetics* / Q000382:microbiology; D007113:Immunity, Innate / Q000235:genetics*; D012275:Oryza / Q000235:genetics; D010935:Plant Diseases / Q000382:microbiology; D012150:Polymorphism, Restriction Fragment Length; D019105:Random Amplified Polymorphic DNA Technique; D026801:Synteny / Q000235:genetics
D017931:DNA Primers; D005819:Genetic Markers