Following the emergence of the Ug99 lineage of Puccinia graminis f. sp. tritici (Pgt) a collective international effort has been undertaken to identify new sources of wheat stem rust resistance effective against these races. Analyses were undertaken in a collection of wheat genotypes gathered from across Africa to identify stem rust resistance effective against the Pgt races found in Eastern an...

Citation: Mourad AMI, Sallam A, Belamkar V, Wegulo S, Bowden R, Jin Y, Mahdy E, Bakheit B, El-Wafaa AA, Poland J and Baenziger PS (2018) Genome-Wide Association Study for Identification and Validation of Novel SNP Markers for Sr6 Stem Rust Resistance Gene in Bread Wheat. Front. Plant Sci. 9:380. doi: 10.3389/fpls.2018.00380 Genome-Wide Association Study for Identification and Validation of Nove...

Two cytologically stable wheat-Dasypyrum breviarisatatum addition lines, Y93-1-6-6 and Y93-1-A6-4, were identified by integrated molecular and cytogenetic techniques. C-banding and genomic in situ hybridization (GISH) showed that Y93-1-6-6 and Y93-1-A6-4 were different wheat-D. breviaristatum additions. A total of 51 markers (primer/enzyme combinations), including 6 PCR-based Landmark Unique Ge...

We combined the recently developed genotyping by sequencing (GBS) method with joint mapping (also known as nested association mapping) to dissect and understand the genetic architecture controlling stem rust resistance in wheat (Triticum aestivum). Ten stem rust resistant wheat varieties were crossed to the susceptible line LMPG-6 to generate F6 recombinant inbred lines. The recombinant inbred ...

The stem-rust-susceptible barley cv. Golden Promise was transformed by Agrobacterium-mediated transformation of immature zygotic embryos with the Rpg1 genomic clone of cv. Morex containing a 520-bp 5' promoter region, 4,919-bp gene region, and 547-bp 3' nontranscribed sequence. Representatives of 42 transgenic barley lines obtained were characterized for their seedling infection response to pat...

Rust diseases remain a significant threat to the production of most cereals including wheat. New sources of resistance are continually sought by breeders to combat the emergence of new pathogen races. Rice is atypical in that it is an intensively grown cereal with no known rust pathogen. The resistance of rice to cereal rust diseases is referred to as nonhost resistance (NHR), a resistance mech...

Tan spot (TS), caused by the fungus Pyrenophora tritici-repentis (Died) Drechs, is an important foliar disease of wheat and has become a threat to world wheat production since the 1970s. In this study a globally diverse pre-1940s collection of 247 wheat genotypes was evaluated against Ptr ToxA, P. tritici-repentis race 1, and stem rust to determine if; (i) acquisition of Ptr ToxA by the P. trit...

Stem rust has become a renewed threat to global wheat production after the emergence and spread of race TTKSK (also known as Ug99) and related races from Africa. To elucidate U.S. winter wheat resistance genes to stem rust, association mapping was conducted using a panel of 137 lines from cooperative U.S. winter wheat nurseries from 2008 and simple sequence repeat (SSR) and sequence tagged site...

In production of perennial ryegrass seed in the Northwest USA, stem rust is the primary disease constraint in terms of management cost and potential yield loss. The USDA-ARS research program on this problem is focused on improved decision making for fungicide use, and tools for genetic improvement. Data from 10 years of field and greenhouse research was used to construct an epidemiological mode...

Probabilities of death of young slashpine infected byfusiform rustpathogen varied with timing and severity of infection. Trees in nine slashpineplantations varying widely in site quality and initial number oftreesperacre hadsimilarprobabilities ofdeathfrom rust. About 90% oftrees with stem infections in thejirst three growing seasons died by age 15 if the gall spanned more than 50% of the circu...