UNLABELLED Leaf rust, caused by Puccinia triticina, is the most common rust disease of wheat. The fungus is an obligate parasite capable of producing infectious urediniospores as long as infected leaf tissue remains alive. Urediniospores can be wind-disseminated and infect host plants hundreds of kilometres from their source plant, which can result in wheat leaf rust epidemics on a continental ...

Rusts are one of the most severe threats to cereal crops because new pathogen races emerge regularly, resulting in infestations that lead to large yield losses. In 1999, a new race of stem rust, Puccinia graminis f. sp. tritici (Pgt TTKSK or Ug99), was discovered in Uganda. Most of the wheat and barley cultivars grown currently worldwide are susceptible to this new race. Pgt TTKSK has already s...

In plants, disease resistance mediated by the gene-for-gene mechanism involves the recognition of specific effector molecules produced by the pathogen either directly or indirectly by the resistance-gene products. This recognition triggers a series of signals, thereby serving as a molecular switch in regulating defense mechanisms by the plants. To understand the mechanism of action of the barle...

To study genome evolution and diversity in barley (Hordeum vulgare), we have sequenced and compared more than 300 kb of sequence spanning the Rph7 leaf rust disease resistance gene in two barley cultivars. Colinearity was restricted to five genic and two intergenic regions representing <35% of the two sequences. In each interval separating the seven conserved regions, the number and type of rep...

Improving resistance to barley leaf rust (caused by Puccinia hordei) is an important breeding objective in most growing regions worldwide. The development and subsequent utilization of high-throughput PCR-based codominant molecular markers remains effective approach select genotypes with multiple genes, permitting efficient gene deployment stewardship. genes Rph20 Rph24 confer widely adult plan...

Leaf diseases, such as powdery mildew and leaf rust, frequently infect barley plants and severely affect the economic value of malting barley. Early detection of barley diseases would facilitate the timely application of fungicides. In a field experiment, we investigated the performance of fluorescence and reflectance indices on (1) detecting barley disease risks when no fungicide is applied an...

Yunnan and Tibet are the lowest cancer mortality and the largest producer for anticancer crops (brown rice, barley, buckwheat, tea, walnut, mushrooms, and so forth). Shanghai and Jiangsu province in China have the highest mortality of cancers, which are associated with the sharp decline of barley.

The objective of this study was to compare the effects on blood pressure of predominantly insoluble fiber (whole wheat and brown rice) and soluble fiber (barley) in a whole-grain diet. Subjects (seven men, nine premenopausal women, and nine postmenopausal women) consumed a controlled Step I diet for 2 weeks; then about 20% of energy was replaced with whole wheat/brown rice, barley, or half whea...

Whole grains have been reported to lower blood pressure, but results have been mixed. This report compares the effects of soluble and insoluble fibers on blood pressure in a whole grain diet. Twenty-one non-hypertensive men (28-62 yr) with elevated plasma cholesterol levels were selected for the study approved by the Institutional Review Board of the Johns Hopkins School of Public Health. Men c...

Nonhost resistance is often conceptualized as a qualitative separation from host resistance. Classification into these two states is generally facile, as they fail to fully describe the range of states that exist in the transition from host to nonhost. This poses a problem when studying pathosystems that cannot be classified as either host or nonhost due to their intermediate status relative to...