Pathotype variation of barley powdery mildew in Western Australia

Induction of Disease Symptoms in Barley by Powdery Mildew.

Powdery millews usually grow superficially on their hosts but produce symptoms of disease throughout the underlying host tissues. The symptoms include marked increase in respiratory rate (1, 3, 15. 24, 26, 30. 35); accumulation of organic and inorganic substances (1,29, 36): increase in dry weight (10. 26) ; increase in wet weight (3) decrease in photosynthesis when the disease is well develope...

Powdery mildew of soybeans.

Effects of Powdery Mildew and Water Stress on CO(2) Exchange in Uninfected Leaves of Barley.

Net photosynthesis is stimulated in third seedling leaves of barley plants whose lower two leaves are heavily infected by Erysiphe graminis f.sp. hordei Marchal. Stimulation is greater in water-stressed than in well-watered plants. In stressed, but not in well-watered plants, stimulation is associated with the maintenance of high leaf water potential and high leaf conductance. A small part of t...

Heterogeneity of Powdery Mildew Resistance Revealed in Accessions of the ICARDA Wild Barley Collection

The primary genepool of barley comprises two subspecies - wild barley (Hordeum vulgare subsp. spontaneum) and cultivated barley H. vulgare. subsp. vulgare. The former originated 5.5 million years ago in southwest Asia and is the immediate ancestor of cultivated barley, which arose around 10,000 years ago. In this study, the specific resistance of a set of 146 wild barley accessions, maintained ...

Genome dynamics and evolution of the Mla (powdery mildew) resistance locus in barley.

Genes that confer defense against pathogens often are clustered in the genome and evolve via diverse mechanisms. To evaluate the organization and content of a major defense gene complex in cereals, we determined the complete sequence of a 261-kb BAC contig from barley cv Morex that spans the Mla (powdery mildew) resistance locus. Among the 32 predicted genes on this contig, 15 are associated wi...