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Resistance to powdery mildew in selections from Tunisian landraces of barley
Author(s) -
Czembor J. H.,
Johnston M. R.
Publication year - 1999
Publication title -
plant breeding
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.583
H-Index - 71
eISSN - 1439-0523
pISSN - 0179-9541
DOI - 10.1046/j.1439-0523.1999.00382.x
Subject(s) - powdery mildew , biology , agronomy , resistance (ecology) , hordeum vulgare , plant disease resistance , poaceae , genetic resources , botany , microbiology and biotechnology , genetics , gene
Two‐hundred and thirty‐two accessions of barley landraces collected from Tunisia were screened for resistance to powdery mildew. A number of race‐specific genes were detected using the detached leaf technique. Among the 232 accessions tested, 169 were susceptible to powdery mildew, 20 were resistant and 43 showed differential reactions to the three isolates of powdery mildew used. An attempt was made to determine the number of genes, the types of gene, the types of gene action and the gene loci in 20 resistant accessions. Three types of cross were made: (1) the accessions were crossed to the susceptible variety ‘Pallas’, (2) the accessions were crossed with ‘Pallas’ isolines, and (2) accessions with identical powdery mildew reaction patterns were intercrossed. Three isolates of Erysiphe graminis f. sp. hordei were used: Bzm‐1, KM 18‐75, R13C. A number of different resistance genes were detected among the 19 resistant accessions. Surprisingly, segregation indicating single genes only were detected with the isolates used. Some of these genes could be associated with loci already known. In 19 cases a dominant and in one a recessive mode of inheritance was detected. The recessive gene was not located at the mlo locus. This investigation represents the first systematic study of race‐specific genes for powdery mildew resistance in Tunisian landraces. The newly identified sources of resistance may be used in many strategies of breeding for disease resistance.