[show abstract][hide abstract] ABSTRACT: The Spanish landrace-derived inbred line SBCC97, together with other lines from the Spanish Barley Core Collection, displays
high resistance to powdery mildew, caused by the fungus Blumeria graminis f. sp. hordei. The objective of this study was to map quantitative trait loci (QTLs) for resistance to powdery mildew in a recombinant
inbred line population derived from a cross between SBCC97 and the susceptible cultivar ‘Plaisant’. Phenotypic analysis was
performed using four B. graminis isolates, and genetic maps were constructed with mainly simple sequence repeat (SSR) markers, following a sequential genotyping
strategy. Two major QTLs with large effects were identified on chromosome 7H, and they accounted for up to 45% of the total
phenotypic variance. The alleles for resistance at each QTL were contributed by the Spanish parent SBCC97. One locus was mapped
to the short arm of chromosome 7HS, and was flanked by the resistance gene analogue (RGA) marker S9202 and the SSR GBM1060.
This corresponded to the same chromosomal region in which a major race-specific resistance gene from Hordeum vulgare ssp. spontaneum, designated as mlt, had been identified previously. The second QTL was linked tightly to marker EBmac0755, and it shared its chromosomal location
with the qualitative resistance gene Mlf, which has only been described previously in the wild ancestor H. spontaneum. This is the first report of these two QTLs occurring together in cultivated barley, and it paves the way for their use in
barley breeding programs that are designed to transfer resistance alleles into elite cultivars.
KeywordsBarley-Powdery mildew-Disease resistance-Quantitative trait locus