Identification of New Genes for Mildew Resistance of Barley at the Mia Locus in Lines Derived from <i>Hordeum spontaneum</i>

Abstract

Abstract Genetical studies have been conducted with lines derived from H. spontaneum showing that these lines carry dominant mildew resistance genes located at or near the Mla , locus. The resistance spectra of the lines ‘RS170—10 × Piccolo A’, ‘Diamant × 1B‐20’, ‘RS1—8 × Piccolo E’ and ‘Diamant × 1B‐151’ obtained from 10 European and Israeli isolates differ from previously‐identified Mia alleles. Therefore, it is suggested that these genes should be designated as Mla 25, Mla 26, Mla .27 and Mla 28, respectively. In addition, the RFLP‐patterns of these lines and their crossing parents were studied by hybridization with probes MWG 1H036, MWG 1H060 and MWG 1H068, which are very closely linked to the Mia locus. Two double crossover events have been identified. The use of RFLP markers for the identification of mildew resistance genes is discussed.