Resistance to powdery mildew (Erysiphe graminisf.sp.hordei) in the barley cultivar Galleon. I. Relationship with known genes for resistance

✍ Scribed by M. A. Hossain; D. H. B. Sparrow

• Publisher: Springer
• Year: 1991
• Tongue: English
• Weight: 636 KB
• Volume: 52
• Category: Article
• ISSN: 0014-2336
• DOI: 10.1007/bf00037850

✦ Synopsis

A study was undertaken into the nature and number of resistance genes in the barley cultivar Galleon against powdery mildew (Erysiphe graminis f.sp. hordei) and the relationship of this resistance with other known resistance genes .

The reactions of Fts, F2s, 173s, and test-cross progenies from crosses of Galleon with three susceptible cultivars (Weeah, Clipper and Sonja) to isolates of the pathogen made in South Australia showed that the resistance in Galleon is conditioned by a single dominant gene in some plants and two dominant genes in other plants . Thus Galleon is a mixture of genotypes differing in reaction to powdery mildew .

When crossed to parents containing known resistance genes both the single dominant gene (in Galleon Selection) and the two dominant genes (in unselected Galleon) segregated independently in F 2s and test-cross progenies . Analysis of the x2 values indicate that the gene(s) in Galleon are definitely different from M1-g, located on chromosome 4, Ml-h on chromosome 6, and from Ml-ra and M1-k which were ineffective in this study . Differences from Ml-a, Ml-a7, Ml-a9 and M1-a12 were of a lower probability indicating linkage . The gene M1-a6 was ineffective in South Australia but the cultivar Midas and its progeny were resistant indicating the presence of a previously undescribed gene . The reaction types of the Galleon genes also showed differences from the Ml-(CP), Ml-p, Ml-v and ml-o3 genes as well as the above nine genes .

The resistance gene in the Galleon Selection is tentatively designated Ml-(Ga) . There is as yet no evidence to determine whether this gene is different from either of the genes in the unselected Galleon .