Simulation studies on epidemics of wheat stripe rust (Puccinia striiformis) on slow-rusting cultivars and analysis of effects of resistance components

AbstractCrop losses caused by plant pathogens are a primary threat to stable food production. Stripe rust (Puccinia striiformis) is a fungal pathogen of cereal crops that causes significant, persistent yield loss. Stripe rust exhibits host species specificity, with lineages that have adapted to infect wheat and barley. While wheat stripe rust and barley stripe rust are commonly restricted to their corresponding hosts, the genes underlying this host specificity remain unknown. Here, we show that three resistance genes, Rps6, Rps7, and Rps8, contribute to immunity in barley to wheat stripe rust. Rps7 cosegregates with barley powdery mildew resistance at the Mla locus. Using transgenic complementation of different Mla alleles, we confirm allele-specific recognition of wheat stripe rust by Mla. Our results show that major resistance genes contribute to the host species specificity of wheat stripe rust on barley and that a shared genetic architecture underlies resistance to the adapted pathogen barley powdery mildew and non-adapted pathogen wheat stripe rust.

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Inheritance and Molecular Mapping of Barley Genes Conferring Resistance to Wheat Stripe Rust

Phytopathology ◽

10.1094/phyto-95-0884 ◽

2005 ◽

Vol 95 (8) ◽

pp. 884-889 ◽

Cited By ~ 22

Author(s):

Vihanga Pahalawatta ◽

Xianming Chen

Keyword(s):

Resistance Gene ◽

Microsatellite Marker ◽

Stripe Rust ◽

Molecular Mapping ◽

Puccinia Striiformis ◽

Infection Type ◽

Dominant Gene ◽

Wheat Stripe Rust ◽

Rust Pathogen ◽

Type Data

Most barley cultivars are resistant to stripe rust of wheat that is caused by Puccinia striiformis f. sp. tritici. The barley cv. Steptoe is susceptible to all identified races of P. striiformis f. sp. hordei (PSH), the barley stripe rust pathogen, but is resistant to most P. striiformis f. sp. tritici races. To determine inheritance of the Steptoe resistance to P. striiformis f. sp. tritici, a cross was made between Steptoe and Russell, a barley cultivar susceptible to some P. striiformis f. sp. tritici races and all tested P. striiformis f. sp. hordei races. Seedlings of parents and F1, BC1, F2, and F3 progeny from the barley cross were tested with P. striiformis f. sp. tritici races PST-41 and PST-45 under controlled greenhouse conditions. Genetic analyses of infection type data showed that Steptoe had one dominant gene and one recessive gene (provisionally designated as RpstS1 and rpstS2, respectively) for resistance to races PST-41 and PST-45. Genomic DNA was extracted from the parents and 150 F2 plants that were tested for rust reaction and grown for seed of F3 lines. The infection type data and polymorphic markers identified using the resistance gene analog polymorphism (RGAP) technique were analyzed with the Mapmaker computer program to map the resistance genes. The dominant resistance gene in Steptoe for resistance to P. striiformis f. sp. tritici races was mapped on barley chromosome 4H using a linked microsatellite marker, HVM68. A linkage group for the dominant gene was constructed with 12 RGAP markers and the microsatellite marker. The results show that resistance in barley to the wheat stripe rust pathogen is qualitatively inherited. These genes might provide useful resistance against wheat stripe rust when introgressed into wheat from barley.

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Pathogens which threaten food security: Puccinia striiformis, the wheat stripe rust pathogen

Food Security ◽

10.1007/s12571-020-01016-z ◽

2020 ◽

Vol 12 (2) ◽

pp. 239-251 ◽

Cited By ~ 9

Author(s):

Xianming Chen

Keyword(s):

Food Security ◽

Stripe Rust ◽

Puccinia Striiformis ◽

Wheat Stripe Rust ◽

Rust Pathogen

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Next Generation Sequencing Provides Rapid Access to the Genome of Puccinia striiformis f. sp. tritici, the Causal Agent of Wheat Stripe Rust

PLoS ONE ◽

10.1371/journal.pone.0024230 ◽

2011 ◽

Vol 6 (8) ◽

pp. e24230 ◽

Cited By ~ 121

Author(s):

Dario Cantu ◽

Manjula Govindarajulu ◽

Alex Kozik ◽

Meinan Wang ◽

Xianming Chen ◽

...

Keyword(s):

Next Generation Sequencing ◽

Stripe Rust ◽

Puccinia Striiformis ◽

Causal Agent ◽

Next Generation ◽

Wheat Stripe Rust ◽

Rapid Access ◽

Generation Sequencing

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Improved Evaluation of Wheat Cultivars (Lines) on Resistance to Puccinia striiformis f. sp. tritici Using Molecular Disease Index

Plant Disease ◽

10.1094/pdis-07-18-1158-re ◽

2019 ◽

Vol 103 (6) ◽

pp. 1206-1212

Author(s):

Bingyao Chu ◽

Lujia Yang ◽

Cuicui Wang ◽

Yilin Gu ◽

Kai Yuan ◽

...

Keyword(s):

Latent Period ◽

Stripe Rust ◽

Field Experiments ◽

Puccinia Striiformis ◽

Quantitative Polymerase Chain Reaction ◽

Disease Index ◽

Wheat Cultivars ◽

Resistance Level ◽

Seedling Resistance ◽

Wheat Stripe Rust

Wheat stripe rust caused by Puccinia striiformis f. sp. tritici is one of the most destructive diseases of wheat worldwide. Sichuan Province plays an important role in interregional epidemics in China. Application of host resistance is important in disease management, and efficient approaches to evaluate resistance level are necessary to obtain useful varieties. In this study, 100 wheat cultivars (lines) growing in Sichuan were selected to evaluate their resistance to stripe rust. Field experiments were conducted with a mixture of three P. striiformis f. sp. tritici races for inoculations at seeding and adult stages in the 2014 to 2015 season and the 2016 to 2017 season. Leaf samplings were conducted four times during the latent period at early growth stage of wheat. The sampled leaves were processed to extract DNA. The DNA of both wheat and P. striiformis f. sp. tritici was quantified using real-time quantitative polymerase chain reaction, and the molecular disease index (MDI) was used to evaluate the resistance level. The area under the disease progress curve in terms of disease index (AUDPC-DI) was obtained for each studied cultivar (line) in the fields. Among the 100 studied cultivars (lines), 61% of them showed seedling resistance, and 63 and 65% showed adult resistance in the 2014 to 2015 and 2016 to 2017 seasons, respectively, based on the infection type. High consistency in resistance grouping by cluster analysis as the percentage of the studied cultivar (line) belonging to the same group based on AUDPC-DI data and based on MDI data was obtained. The correlations between AUDPC-DI and MDI from samples collected on 9 and 14 or 15 days after inoculation during the latent period were all significant at P < 0.01. This study provided a new and efficient method for evaluation of varietal resistance to wheat stripe rust.

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Quantitative Trait Loci for High-Temperature Adult-Plant and Slow-Rusting Resistance to Puccinia striiformis f. sp. tritici in Wheat Cultivars

Phytopathology ◽

10.1094/phyto-98-7-0803 ◽

2008 ◽

Vol 98 (7) ◽

pp. 803-809 ◽

Cited By ~ 43

Author(s):

Q. Guo ◽

Z. J. Zhang ◽

Y. B. Xu ◽

G. H. Li ◽

J. Feng ◽

...

Keyword(s):

High Temperature ◽

Stripe Rust ◽

Phenotypic Variation ◽

Quantitative Trait ◽

Puccinia Striiformis ◽

Infection Type ◽

Adult Plant ◽

Wheat Cultivars ◽

Slow Rusting ◽

Adult Plants

Stripe rust, caused by Puccinia striiformis f. sp. tritici, is one of the most damaging diseases of wheat (Triticum aestivum) globally. High-temperature adult-plant resistance (HTAPR) and slow-rusting have great potential for sustainable management of the disease. The wheat cultivars Luke and Aquileja have been previously reported to possess HTAPR and slow-rusting to stripe rust, respectively. Aquileja displayed less number of stripes per unit leaf area than Luke, while Luke showed lower infection type than Aquileja at adult-plant stages of growth under high-temperature conditions. The objectives of this study were to confirm the resistances and to map the resistance genes in Luke and Aquileja. Luke was crossed with Aquileja, and 326 of the F2 plants were genotyped using 282 microsatellite primer pairs. These F2 plants and their derived F3 families were evaluated for resistance to stripe rust by inoculation in the fields and greenhouses of high- and low-temperatures. Infection type was recorded for both seedlings and adult plants, and stripe number was recorded for adult plants only. Two quantitative trait loci (QTL) were identified, on the short arm of chromosome 2B, to be significantly associated with infection type at adult-plant stages in the fields and in the high-temperature greenhouse. The locus distal to centromere, referred to as QYrlu.cau-2BS1, and the locus proximal to centromere, referred to as QYrlu.cau-2BS2, were separated by a genetic distance of about 23 cM. QYrlu.cau-2BS1 was flanked by the microsatellite markers Xwmc154 and Xgwm148, and QYrlu.cau-2BS2 was flanked by Xgwm148 and Xabrc167. QYrlu.cau-2BS1 and QYrlu.cau-2BS2 explained up to 36.6 and 41.5% of the phenotypic variation of infection type, respectively, and up to 78.1% collectively. No significant interaction between the two loci was detected. Another QTL, referred to as QYraq.cau-2BL, was detected on the long arm of chromosome 2B to be significantly associated with stripe number. QYraq.cau-2BL was flanked by the microsatellite markers Xwmc175 and Xwmc332, and it explained up to 61.5% of the phenotypic variation of stripe number. It is possible that these three QTL are previously unmapped loci for resistance to stripe rust.

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High Relative Parasitic Fitness of G22 Derivatives is Associated with the Epidemic Potential of Wheat Stripe Rust in China

Plant Disease ◽

10.1094/pdis-04-17-0511-sr ◽

2018 ◽

Vol 102 (3) ◽

pp. 483-487 ◽

Cited By ~ 9

Author(s):

Bing Bing Bai ◽

Tai Guo Liu ◽

Bo Liu ◽

Li Gao ◽

Wan Quan Chen

Keyword(s):

Latent Period ◽

Stripe Rust ◽

Large Scale ◽

Puccinia Striiformis ◽

Germination Rate ◽

Durable Resistance ◽

Wheat Cultivars ◽

Wheat Stripe Rust ◽

Expansion Speed ◽

Parasitic Fitness

In total, 13 commercial wheat cultivars around China and four races of Puccinia striiformis f. sp. tritici (namely, CYR32, CYR33, G22-9, and G22-14) were employed for a test of relative parasitic fitness (RPF) using the drop method. The RPF values were measured, including the urediniospore germination rate, the latent period, the uredinial length, the uredinial density, the infection area, the sporulation intensity, the lesion expansion speed, and the sporulation period. The results indicated that the parameters of relative parasitic fitness of the four P. striiformis f. sp. tritici races on the 13 wheat cultivars were significantly different (P = 0.00) in sporulation intensity, lesion expansion speed, uredinial length, sporulation period, uredinial density, and latent period. The urediniospore germination rates of the four P. striiformis f. sp. tritici races for the test were significantly different (P = 0.00), whereas no correlation with the different cultivars was observed (P = 1.00). The infection areas of the tested races on the different cultivars were significantly different (P = 0.00) but there were no obvious manifestations among the various races (P = 0.20). Principal component analysis (PCA) showed that the sporulation intensity represented sporulation capacity and scalability, the latent period indicated infection ability, and the urediniospore germination rate represented urediniospore vigor, all of which fully contributed to the RPF in the interaction of the four races and 13 wheat cultivars, which was calculated by the following formula: RPF = (sporulation intensity × urediniospore germination rate)/latent period. The sporulation and infection of G22-9 on the 13 large-scale cultivated cultivars were the highest, and the RPF of G22-9 was higher than that of the predominant races, CYR32 and CYR33. This result suggested that G22-9 could become a new predominant race and potentially cause epidemics of wheat stripe rust in China. To prevent potential epidemics, susceptible wheat cultivars should be withdrawn from production and breeding programs should reduce the use of Yr10 and Yr26 and use other more effective resistance genes in combination with nonrace-specific resistance for developing wheat cultivars with durable resistance to stripe rust.

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Primary Disease Gradients of Wheat Stripe Rust in Large Field Plots

Phytopathology ◽

10.1094/phyto-95-0983 ◽

2005 ◽

Vol 95 (9) ◽

pp. 983-991 ◽

Cited By ~ 24

Author(s):

Kathryn E. Sackett ◽

Christopher C. Mundt

Keyword(s):

Stripe Rust ◽

Power Law ◽

Puccinia Striiformis ◽

Exponential Model ◽

Plant Diseases ◽

Large Field ◽

Data Sets ◽

Wheat Stripe Rust ◽

Primary Disease ◽

Modified Power Law

Field data on disease gradients are essential for understanding the spread of plant diseases. In particular, dispersal far from an inoculum source can drive the behavior of an expanding focal epidemic. In this study, primary disease gradients of wheat stripe rust, caused by the aerially dispersed fungal pathogen Puccinia striiformis, were measured in Madras and Hermiston, OR, in the spring of 2002 and 2003. Plots were 6.1 m wide by 128 to 171 m long, and inoculated with urediniospores in an area of 1.52 by 1.52 m. Gradients were measured as far as 79.2 m downwind and 12.2 m upwind of the focus. Four gradient models—the power law, the modified power law, the exponential model, and the Lambert's general model—were fit to the data. Five of eight gradients were better fit by the power law, modified power law, and Lambert model than by the exponential, revealing the non-exponentially bound nature of the gradient tails. The other three data sets, which comprised fewer data points, were fit equally well by all the models. By truncating the largest data sets (maximum distances 79.2, 48.8, and 30.5 m) to within 30.5, 18.3, and 6.1 m of the focus, it was shown how the relative suitability of dispersal models can be obscured when data are available only at a short distance from the focus. The truncated data sets were also used to examine the danger associated with extrapolating gradients to distances beyond available data. The power law and modified power law predicted dispersal at large distances well relative to the Lambert and exponential models, which consistently and sometimes severely underestimated dispersal at large distances.

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