Identification of leaf rust resistance loci in hard winter wheat using genome-wide association mapping.

Leaf rust, caused by Puccinia triticina (Pt), is a serious constraint to wheat production. Developing resistant varieties is the best approach to managing this disease. Wheat leaf rust resistance (Lr) genes have been classified into either all-stage resistance (ASR) or adult-plant resistance (APR).

Genomes of Aegilops umbellulata provide new insights into unique structural variations and genetic diversity in the U-genome for wheat improvement.

Aegilops umbellulata serve as an important reservoir for novel biotic and abiotic stress tolerance for wheat improvement. However, chromosomal rearrangements and evolutionary trajectory of this species remain to be elucidated. Here, we present a comprehensive investigation into Ae.

Origin and evolution of the bread wheat D genome.

Bread wheat (Triticum aestivum) is a globally dominant crop and major source of calories and proteins for the human diet. Compared with its wild ancestors, modern bread wheat shows lower genetic diversity, caused by polyploidisation, domestication and breeding bottlenecks. Wild wheat relatives represent genetic reservoirs, and harbour diversity and beneficial alleles that have not been incorporated into bread wheat.

Characterization of Quantitative Trait Loci for Leaf Rust Resistance in the Uzbekistani Wheat Landrace Teremai Bugdai.

Leaf rust, caused by , is a major cause of wheat yield losses globally, and novel leaf rust resistance genes are needed to enhance wheat leaf rust resistance. Teremai Bugdai is a landrace from Uzebekistan that is highly resistant to many races of in the United States. To unravel leaf rust resistance loci in Teremai Bugdai, a recombinant inbred line (RIL) population of Teremai Bugdai × TAM 110 was evaluated for response to race (TNBGJ) and genotyped using single nucleotide polymorphism (SNP) markers generated by genotyping-by-sequencing (GBS).

Mapping and characterization of the recessive leaf rust resistance gene Lr83 on wheat chromosome arm 1DS.

The leaf rust resistance gene in Thatcher wheat derivative 78-1 was mapped to chromosome 1DS with SNP markers and designated as Lr83. 'Thatcher' wheat near isogenic line RL6149, a putative derivative of Triticum dicoccoides, was previously determined to carry leaf rust resistance gene Lr64 on chromosome arm 6AL and a second gene temporarily named LrX on chromosome arm 1DS. The objective of this study was to map and characterize LrX in a population of recombinant inbred lines (RILs) that segregated for a single gene.

Identification of leaf rust resistance loci in a geographically diverse panel of wheat using genome-wide association analysis.

Leaf rust, caused by () is among the most devastating diseases posing a significant threat to global wheat production. The continuously evolving virulent races in North America calls for exploring new sources of leaf rust resistance. A diversity panel of 365 bread wheat accessions selected from a worldwide population of landraces and cultivars was evaluated at the seedling stage against four races (TDBJQ, TBBGS, MNPSD and, TNBJS).

The World Health Organization's public health intelligence activities during the COVID-19 pandemic response, December 2019 to December 2021.

The coronavirus disease (COVID-19) presented a unique opportunity for the World Health Organization (WHO) to utilise public health intelligence (PHI) for pandemic response. WHO systematically captured mainly unstructured information (e.g.

High-Resolution Melting-Based Marker Development for Wheat Leaf Rust Resistance Gene .

Deploying adult plant resistance (APR) against rust diseases is an important breeding objective of most wheat-breeding programs. The gene is an effective and widely deployed broad-spectrum APR gene in wheat against leaf rust fungus . Various molecular markers have been developed for , but they either require post-PCR handling processes or are not economical.

Identification and characterization of the novel leaf rust resistance gene Lr81 in wheat.

The novel, leaf rust seedling resistance gene, Lr81, was identified in a Croatian breeding line and mapped to a genomic region of less than 100 Kb on chromosome 2AS. Leaf rust, caused by Puccinia triticina, is the most common and widespread rust disease in wheat. Races of Puccinia triticina evolve rapidly in the southern Great Plains of the USA, and leaf rust resistance genes often lose effectiveness shortly after deployment in wheat production.

Adult plant leaf rust resistance QTL derived from wheat line CI13227 maps to chromosomes 2AL, 4BS, and 7AL.

The winter wheat (Triticum aestivum L.) line CI13227 has been characterized as having adult plant resistance to leaf rust caused by Puccinia triticina Eriks (Pt). Line CI13227 was crossed with the susceptible spring wheat 'Thatcher' (Tc) and a Tc*2/CI13227 F line with adult plant leaf rust resistance designated as 411A was derived.

Virulence Phenotypes of the Wheat Leaf Rust Pathogen, , in the United States from 2018 to 2020.

Collections of wheat leaves infected with the leaf rust fungus, , were obtained from the southeastern states, the Ohio Valley, the Great Plains, and Washington in 2018, 2019, and 2020 to determine the prevalent virulence phenotypes in the wheat-growing regions of the United States. In the hard red winter wheat region of the southern and mid Great Plains, MNPSD and MPPSD were the two most common phenotypes in 2018 and 2019. In 2020, BBBQD with high virulence to durum wheat was the most common phenotype in the southern Great Plains.

Whole-genome sequencing of multiple isolates of Puccinia triticina reveals asexual lineages evolving by recurrent mutations.

The wheat leaf rust fungus, Puccinia triticina Erikss., is a worldwide pathogen of tetraploid durum and hexaploid wheat. Many races of P.

Genotype Groups of the Wheat Leaf Rust Fungus in the United States as Determined by Genotyping by Sequencing.

Wheat leaf rust caused by is a widespread disease of wheat in the United States and worldwide. Populations of are characterized by virulence phenotypes that change rapidly because of selection by wheat cultivars with leaf rust resistance genes. The objective of this study was to genotype collections of from 2011 to 2018 in the United States using restriction site-associated genotyping by sequencing (GBS) to determine if recently identified new virulence phenotypes belong to established genotype groups or to groups previously not detected.

Genome-Wide Association Studies Reveal All-Stage Rust Resistance Loci in Elite Durum Wheat Genotypes.

Leaf rust, caused by (), stripe rust caused by f. sp. (), and stem rust caused by f.

A five-transgene cassette confers broad-spectrum resistance to a fungal rust pathogen in wheat.

Breeding wheat with durable resistance to the fungal pathogen Puccinia graminis f. sp. tritici (Pgt), a major threat to cereal production, is challenging due to the rapid evolution of pathogen virulence.

Adult Plant Leaf Rust Resistance in AC Taber Wheat Maps to Chromosomes 2BS and 3BS.

AC Taber is a hard red spring wheat cultivar that has had long-lasting resistance to the leaf rust fungus . The objective of this study was to determine the chromosome location of the leaf rust resistance genes in AC Taber. The leaf rust-susceptible cultivar Thatcher was crossed with AC Taber to develop an F recombinant inbred line (RIL) population.

Genotyping-by-Sequencing for the Study of Genetic Diversity in .

Leaf rust, caused by Erikss., is globally the most widespread rust of wheat. Populations of are highly diverse for virulence, with many different races found annually.

Identifying Loci Conferring Resistance to Leaf and Stripe Rusts in a Spring Wheat Population () via Genome-Wide Association Mapping.

A previous genome-wide association study (GWAS) for leaf rust (caused by ) resistance identified 46 resistance quantitative trait loci (QTL) in an elite spring wheat leaf rust resistance diversity panel. With the aim of characterizing the pleiotropic resistance sources to both leaf rust and stripe rust (caused by f. sp.

Thatcher wheat line RL6149 carries Lr64 and a second leaf rust resistance gene on chromosome 1DS.

The leaf rust resistance gene Lr64 in the Thatcher wheat RL6149 was mapped to chromosome 6AL with SNP and KASP markers and a second leaf rust resistance gene was mapped to chromosome 1DS. RL6149, a near-isogenic line of Thatcher wheat, carries leaf rust resistance gene Lr64 on chromosome arm 6AL. The objective of this study was to develop molecular markers that can be easily used to select wheat lines with Lr64.

Virulence of , the Wheat Leaf Rust Fungus, in the United States in 2017.

Samples of wheat leaves infected with the leaf rust fungus, , were obtained in 2017 from agricultural experiment station plots, demonstration plots, and farm fields in the Great Plains, the Ohio Valley, the southeastern states, California, and Washington in order to determine the prevalent virulence phenotypes present in the United States. A total of 65 virulence phenotypes were identified among the 469 single uredinial isolates that were tested on 20 near-isogenic lines of Thatcher wheat that differ for leaf rust resistance genes. Virulence phenotypes MBTNB at 11.

Multilocus Genotypes of the Wheat Leaf Rust Fungus in Worldwide Regions Indicate Past and Current Long-Distance Migration.

Many plant pathogenic fungi have a global distribution across diverse ecological zones and agricultural production systems. , the wheat leaf rust fungus, is a major pathogen in many wheat production areas of the world. The objective of this research was to determine the genetic relatedness of in different worldwide regions.

Physiologic Specialization of Puccinia triticina on Wheat in the United States in 2015.

Leaves of wheat infected with the leaf rust fungus, Puccinia triticina, were obtained from farm fields and breeding plots at experimental stations in the Great Plains, Ohio River Valley, and southeastern states in 2015 in order to identify virulence phenotypes prevalent in the United States in different wheat growing regions. A total of 526 single uredinial isolates derived from the leaf rust collections were tested for virulence to 20 lines of Thatcher wheat that differ for single leaf rust resistance genes. A total of 60 virulence phenotypes were described in the United States in 2015.