Puccinia triticina population structure on winter and spring wheat in Saratov Region during 2013–2017

Stripe rust (Puccinia striiformis f. sp. tritici) and leaf rust (Puccinia triticina) can cause significant yield reductions to hard red spring wheat (HRSW) in North Dakota (ND). The use of host resistance and fungicides can successfully manage this disease. However, the combination of them may not be appropriate every year. From 2016 to 2018, fungicide timing by cultivar experiments were conducted to update recommendations for rust management. Experiments were designed in a randomized complete block with a split-plot arrangement. Main plots included three HRSW cultivars that were moderately resistant, moderately susceptible, and susceptible. Subplots included the fungicide timings of Feekes 9, Feekes 10.5.1, a sequential application, and a nontreated control. Field experiments were categorized into three environments depending on rust onset and disease progress. When rust was detected at early heading, the susceptible cultivar benefited from all fungicide application timings. The detection of rust at tillering leaf stages suggested that fungicide treatments statistically lowered disease and in most cases had statistically higher yield, regardless of host resistance. These results suggest that the benefit from a fungicide application to manage leaf rust and stripe rust is highly influenced by the timing of disease onset and level of host resistance. Results will improve fungicide suggestions for HRSW producers in ND.

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Population structure of Nepali spring wheat (Triticum aestivum L.) germplasm

BMC Plant Biology ◽

10.1186/s12870-020-02722-8 ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Kamal Khadka ◽

Davoud Torkamaneh ◽

Mina Kaviani ◽

Francois Belzile ◽

Manish N. Raizada ◽

...

Keyword(s):

Genetic Diversity ◽

Triticum Aestivum ◽

Population Structure ◽

Food Security ◽

Spring Wheat ◽

Principal Component ◽

Genotyping By Sequencing ◽

Triticum Aestivum L ◽

Wheat Breeding ◽

Exotic Germplasm

Abstract Background Appropriate information about genetic diversity and population structure of germplasm improves the efficiency of plant breeding. The low productivity of Nepali bread wheat (Triticum aestivum L.) is a major concern particularly since Nepal is ranked the 4th most vulnerable nation globally to climate change. The genetic diversity and population structure of Nepali spring wheat have not been reported. This study aims to improve the exploitation of more diverse and under-utilized genetic resources to contribute to current and future breeding efforts for global food security. Results We used genotyping-by-sequencing (GBS) to characterize a panel of 318 spring wheat accessions from Nepal including 166 landraces, 115 CIMMYT advanced lines, and 34 Nepali released varieties. We identified 95 K high-quality SNPs. The greatest genetic diversity was observed among the landraces, followed by CIMMYT lines, and released varieties. Though we expected only 3 groupings corresponding to these 3 seed origins, the population structure revealed two large, distinct subpopulations along with two smaller and scattered subpopulations in between, with significant admixture. This result was confirmed by principal component analysis (PCA) and UPGMA distance-based clustering. The pattern of LD decay differed between subpopulations, ranging from 60 to 150 Kb. We discuss the possibility that germplasm explorations during the 1970s–1990s may have mistakenly collected exotic germplasm instead of local landraces and/or collected materials that had already cross-hybridized since exotic germplasm was introduced starting in the 1950s. Conclusion We suggest that only a subset of wheat “landraces” in Nepal are authentic which this study has identified. Targeting these authentic landraces may accelerate local breeding programs to improve the food security of this climate-vulnerable nation. Overall, this study provides a novel understanding of the genetic diversity of wheat in Nepal and this may contribute to global wheat breeding initiatives.

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RESISTANT OF TRITICUM AESTIVUM VARIETIES OF DIFFERENT ORIGIN TO BIOTIC STRESSORS ON THE FOREST-STEPPE AND STEPPE ZONES OF ORENBURG URALS

Vestnik of Kazan state agrarin university ◽

10.12737/14786 ◽

2015 ◽

Vol 10 (3) ◽

pp. 134-139

Author(s):

Тимошенкова ◽

Tatyana Timoshenkova ◽

Мухитов ◽

Lenar Mukhitov ◽

Самуилов ◽

...

Keyword(s):

Leaf Rust ◽

Spring Wheat ◽

Puccinia Triticina ◽

Steppe Zone ◽

Bipolaris Sorokiniana ◽

Forest Steppe ◽

Local Breeding ◽

New Varieties ◽

The Stability ◽

Different Origin

The article summarizes the results of surveys on the development of the spring wheat disease. The composition of the pathogenic complex in the Orenburg region was analyzed. The paper cites an assessment of the stability of varieties of different origin in the forest steppe and steppe zones of Orenburg Urals. The most common and harmful diseases of spring wheat were: brown leaf rust (Puccinia triticina), stem rust (Puccinia graminis), oidium (Erysiphe graminis, Blumeria graminis Speer.), helminthiasis and fusariose root rot (Bipolaris sorokiniana and Fusarium spp.). Among the samples of local breeding Orenburgskaya 13 variety was the strongly susceptible to the disease of wheat. Logachevka and Uchitel variety were mildly susceptible. Varyag variety was characterized by susceptibility to leaf rust, oidium and dust-brand. According to the complex resistance to diseases of the local races of wheat, we can allocate the following varieties: in the forest-steppe zone: Kinelskaya 59, Kinelskaya 60, Saratovskaya 55, Tulaykovskaya 5, steppe Tulaykovskaya, YuV 4 and in the steppe zone - Belyanka, Saratovskaya 70, Tulaykovskaya 10 and steppe Tulaykovskaya. The inclusion of these varieties in the hybridization will provide a more disease-resistant hybrids and new varieties of spring wheat.

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Genetics of Leaf Rust Resistance in Brambling Wheat

Plant Disease ◽

10.1094/pdis-92-7-1111 ◽

2008 ◽

Vol 92 (7) ◽

pp. 1111-1118 ◽

Cited By ~ 5

Author(s):

J. X. Zhang ◽

R. P. Singh ◽

J. A. Kolmer ◽

J. Huerta-Espino ◽

Y. Jin ◽

...

Keyword(s):

Leaf Rust ◽

Spring Wheat ◽

Resistance Genes ◽

Recombinant Inbred Lines ◽

Puccinia Triticina ◽

Leaf Rust Resistance ◽

The United States ◽

Adult Plant ◽

Slow Rusting ◽

Adult Plants

The CIMMYT-developed spring wheat ‘Brambling’ has a high level of adult-plant resistance (APR) to leaf rust caused by Puccinia triticina. Our objectives were to determine the genetic basis of resistance in seedlings and adult plants and the magnitude of genotype × environment effects on the expression of APR. Brambling was crossed with spring wheat ‘Jupateco 73S’ that is highly susceptible to current predominant P. triticina races in Mexico and the United States. The F1, F2:3, F4:5, F4:6, and F5:7 recombinant inbred lines (RILs) were evaluated under artificial field epidemics in Mexico and St. Paul, MN. The RILs also were tested with five races of P. triticina in greenhouse seedling experiments. A DNA marker was used to postulate the presence of slow-rusting gene Lr34 in the RILs. F1 data suggested strong dominant effect of the APR genes in Brambling. The proportion of homozygous susceptible lines in each generation indicated the presence of three effective resistance genes in adult plants of Brambling in tests in Mexico and three or four genes in tests in St. Paul. The RILs segregated for seedling genes Lr14a and Lr23 and adult-plant slow-rusting gene Lr34 derived from Brambling and Lr17a from Jupateco 73S. Gene Lr23 conditioned APR to P. triticina races present in the St. Paul nursery and accounted for the additional effective gene at this location. Expression of APR was influenced by the environment in the RILs, even though Brambling displayed a consistent response, indicating that stability of APR can be achieved by combinations of slow-rusting resistance genes.

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Evaluation of Wheat Germplasm for Resistance to Leaf Rust (Puccinia triticina) and Identification of the Sources of Lr Resistance Genes Using Molecular Markers

Plants ◽

10.3390/plants10071484 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1484

Author(s):

Alma Kokhmetova ◽

Shynbolat Rsaliyev ◽

Makpal Atishova ◽

Madina Kumarbayeva ◽

Angelina Malysheva ◽

...

Keyword(s):

Molecular Markers ◽

Leaf Rust ◽

Spring Wheat ◽

Resistance Genes ◽

Rust Resistance ◽

Puccinia Triticina ◽

Leaf Rust Resistance ◽

Seedling Resistance ◽

Rust Resistance Genes ◽

Leaf Rust Resistance Genes

Leaf rust, caused by Puccinia triticina (Ptr), is a significant disease of spring wheat spread in Kazakhstan. The development of resistant cultivars importantly requires the effective use of leaf rust resistance genes. This study aims to: (i) determine variation in Ptr population using races from the East Kazakhstan, Akmola, and Almaty regions of Kazakhstan; (ii) examine resistance during seedling and adult plant stages; and (iii) identify the sources of Lr resistance genes among the spring wheat collection using molecular markers. Analysis of a mixed population of Ptr identified 25 distinct pathotypes. Analysis of these pathotypes using 16 Thatcher lines that are near-isogenic for leaf rust resistance genes (Lr) showed different virulence patterns, ranging from least virulent “CJF/B” and “JCL/G” to highly virulent “TKT/Q”. Most of the pathotypes were avirulent to Lr9, Lr19, Lr24, and Lr25 and virulent to Lr1, Lr2a, Lr3ka, Lr11, and Lr30. The Ptr population in Kazakhstan is diverse, as indicated by the range of virulence observed in five different races analyzed in this study. The number of genotypes showed high levels of seedling resistance to each of the five Ptr races, thus confirming genotypic diversity. Two genotypes, Stepnaya 62 and Omskaya 37, were highly resistant to almost all five tested Ptr pathotypes. Stepnaya 62, Omskaya 37, Avangard, Kazakhstanskaya rannespelaya, and Kazakhstanskaya 25 were identified as the most stable genotypes for seedling resistance. However, most of the varieties from Kazakhstan were susceptible in the seedling stage. Molecular screening of these genotypes showed contrasting differences in the genes frequencies. Among the 30 entries, 22 carried leaf rust resistance gene Lr1, and two had Lr9 and Lr68. Lr10 and Lr28 were found in three and four cultivars, respectively. Lr19 was detected in Omskaya 37. Two single cultivars separately carried Lr26 and Lr34, while Lr37 was not detected in any genotypes within this study. Field evaluation demonstrated that the most frequent Lr1 gene is ineffective. Kazakhstanskaya 19 and Omskaya 37 had the highest number of resistance genes: three and four Lr genes, respectively. Two gene combinations (Lr1, Lr68) were detected in Erythrospermum 35 and Astana. The result obtained may assist breeders in incorporating effective Lr genes into new cultivars and developing cultivars resistant to leaf rust.

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POPULATION STRUCTURE OF LEAF PATHOGENS OF COMMON SPRING WHEAT IN THE WEST ASIAN REGIONS OF RUSSIA AND NORTH KAZAKHSTAN IN 2017

Vavilov Journal of Genetics and Breeding ◽

10.18699/vj18.372 ◽

2018 ◽

Vol 22 (3) ◽

pp. 363-369 ◽

Cited By ~ 7

Author(s):

E. I. Gultyaeva ◽

N. M. Kovalenko ◽

V. P. Shamanin ◽

V. A. Tyunin ◽

E. R. Shreyder ◽

...

Keyword(s):

Population Structure ◽

Spring Wheat ◽

The West ◽

Regions Of Russia

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Genetic diversity and selective sweeps in historical and modern Canadian spring wheat cultivars using the 90K SNP array

Scientific Reports ◽

10.1038/s41598-021-02666-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Kassa Semagn ◽

Muhammad Iqbal ◽

Nikolaos Alachiotis ◽

Amidou N’Diaye ◽

Curtis Pozniak ◽

...

Keyword(s):

Genetic Diversity ◽

Population Structure ◽

Genetic Differentiation ◽

Spring Wheat ◽

Snp Array ◽

Categorical Variables ◽

Selective Sweeps ◽

Wheat Cultivars ◽

Breeding Programs ◽

The Impact

AbstractPrevious molecular characterization studies conducted in Canadian wheat cultivars shed some light on the impact of plant breeding on genetic diversity, but the number of varieties and markers used was small. Here, we used 28,798 markers of the wheat 90K single nucleotide polymorphisms to (a) assess the extent of genetic diversity, relationship, population structure, and divergence among 174 historical and modern Canadian spring wheat varieties registered from 1905 to 2018 and 22 unregistered lines (hereinafter referred to as cultivars), and (b) identify genomic regions that had undergone selection. About 91% of the pairs of cultivars differed by 20–40% of the scored alleles, but only 7% of the pairs had kinship coefficients of < 0.250, suggesting the presence of a high proportion of redundancy in allelic composition. Although the 196 cultivars represented eight wheat classes, our results from phylogenetic, principal component, and the model-based population structure analyses revealed three groups, with no clear structure among most wheat classes, breeding programs, and breeding periods. FST statistics computed among different categorical variables showed little genetic differentiation (< 0.05) among breeding periods and breeding programs, but a diverse level of genetic differentiation among wheat classes and predicted groups. Diversity indices were the highest and lowest among cultivars registered from 1970 to 1980 and from 2011 to 2018, respectively. Using two outlier detection methods, we identified from 524 to 2314 SNPs and 41 selective sweeps of which some are close to genes with known phenotype, including plant height, photoperiodism, vernalization, gluten strength, and disease resistance.

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