Mapping and confirmation of two genes conferring resistance to soybean rust ( Phakopsora pachyrhizi ) in the soybean line UG‐5 ( Glycine max )

2020 ◽  
Vol 139 (5) ◽  
pp. 932-942
Author(s):  
Chandra Paul ◽  
Glen L. Hartman ◽  
Brian W. Diers ◽  
David R. Walker
Keyword(s):  
Glycine Max ◽  
Soybean Rust ◽  
Phakopsora Pachyrhizi ◽  
Soybean Line

scholarly journals Resistance to Asian soybean rust in soybean lines with the pyramided three Rpp genes

2013 ◽  
Vol 13 (1) ◽  
pp. 75-82 ◽  
Author(s):  
Naoki Yamanaka ◽  
Noelle G Lemos ◽  
Miori Uno ◽  
Hajime Akamatsu ◽  
Yuichi Yamaoka ◽  
...  
Keyword(s):  
Genetic Background ◽  
Susceptible Variety ◽  
Soybean Rust ◽  
Phakopsora Pachyrhizi ◽  
Soybean Line ◽  
Pathogen Population ◽  
Resistance Level ◽  
Asian Soybean Rust ◽  
High Level

In this study, the influence of genetic background on the resistance level of a soybean line carrying Rpp2, Rpp4, and Rpp5 was evaluated by backcrossing it with a susceptible variety. It was also evaluated eight lines which carry these Rpp genes against five Asian soybean rust (ASR) isolates, in order to determine the likely range of resistance against ASR isolates differing in pathogenicity. The results indicated that a high level of resistance against various ASR isolates could be retained in lines carrying the three Rpp genes in susceptible genetic backgrounds, although minor influences of plant genetic background and ASR pathogenicity to the ASR resistance could occur. Thus, lines with the pyramided three Rpp genes should be effective against a complex pathogen population consisting of diverse Phakopsora pachyrhizi isolates.

scholarly journals Effect of Silicon Absorption on Soybean Resistance to Phakopsora pachyrhizi in Different Cultivars

Plant Disease ◽  
2012 ◽  
Vol 96 (1) ◽  
pp. 37-42 ◽  
Author(s):  
Geneviève Arsenault-Labrecque ◽  
James G. Menzies ◽  
Richard R. Bélanger
Keyword(s):  
Glycine Max ◽  
Soybean Rust ◽  
Phakopsora Pachyrhizi ◽  
Chemical Analyses ◽  
Disease Symptoms ◽  
Soybean Cultivars ◽  
Soybean Resistance ◽  
Soybean Plants ◽  
Si Content ◽  
Innate Ability

Silicon (Si) is recognized for its prophylactic role in alleviating diseases when absorbed by plants and has been proposed as a possible solution against soybean rust, caused by Phakopsora pachyrhizi. However, little is known about its potential effects on soybean (Glycine max) because the plant's ability to absorb Si is poorly defined. In this work, our objectives were to evaluate and quantify the absorption of Si in leaves of different soybean cultivars and to determine if such absorption was able to enhance resistance to soybean rust. In a first set of experiments with cv. Williams 82, hydroponic plants were supplied or not with Si and inoculated with urediniospores of P. pachyrhizi. Chemical analyses revealed no significant differences in the plants' Si content regardless of the treatment, which translated into no effect on rust incidence. However, in a second set of experiments with different cultivars, plants of Korean cultivar Hikmok sorip absorbed nearly four times more Si than those of Williams 82. At the same time, plants from this cultivar exhibited a near absence of disease symptoms when supplied with Si. This resistance appeared to be the result of hypersensitive (HR) reactions that were triggered when plants were fed with Si. These results support the concept that a plant's innate ability to absorb Si will dictate the benefits conferred by a treatment with Si and provide evidence that Si can protect soybean plants against soybean rust through mediated resistance.

scholarly journals Foliar fortification of Copper (Cu) in Glycine max L. for the protection against Asian Soybean Rust (Phakopsora pachyrhizi Syd. & P.Syd.)

2020 ◽  
Vol 7 (4) ◽  
Author(s):  
Edevan Bedin ◽  
Andréia Caverzan ◽  
Diógenes Cecchin Silveira ◽  
Geraldo Chavarria
Keyword(s):  
Glycine Max ◽  
Grain Yield ◽  
Lignin Content ◽  
Foliar Spray ◽  
Plant Performance ◽  
Soybean Rust ◽  
Phakopsora Pachyrhizi ◽  
Asian Soybean Rust ◽  
Glycine Max L ◽  
Rust Severity

The Asian Soybean Rust caused by the fungus Phakopsora pachyrhizi is one of the serious phytosanitary problems faced by soybean [Glycine max (L.) Merrill], which cause up to 80% yield loss. An alternative for the integrated management of the disease is the use of mineral nutrition together with phytosanitary treatments. Thus, the objective of this study is to understand the effect of foliar fortification with copper (Cu) along with phytosanitary treatments in the soybean reaction to Rust by lignin content variation in leaf tissues, and how it reflects the yield. The experimental design was a randomized block with four replicates. Four concentrations Cu (30, 60, 90, 120 g Cu ha-1) were tested in two distinct sources (cuprous oxide and copper carbonate) together with phytosanitary treatments. Evaluations were made to determine the progression of Asian Rust severity, micronutrient content in leaves and grains, as well as lignin content in leaves. The grain yield components and productivity were also evaluated. The Cu contents in the soybean leaves and grains were influenced by foliar spraying. Foliar spray with Cu retarded the disease progression, reducing the severity of Asian Rust and positively impacting grain yield. The amount of lignin present in the leaves was altered considerably with the application of the Cu associated with phytosanitary treatments. The results suggest that the leaf nutrition with copper together with phytosanitary treatments, may reduce the rust severity and improvement the plant performance. Future research with Cu application and analysis of specific enzymes, secondary metabolites and cell wall thickness may further contribute to the understanding of the role of Cu in defence against Asian Soybean Rust.

scholarly journals Diagrammatic scale for assessment of soybean rust severity

2006 ◽  
Vol 31 (1) ◽  
pp. 63-68 ◽  
Author(s):  
Cláudia V. Godoy ◽  
Lucimara J. Koga ◽  
Marcelo G. Canteri
Keyword(s):  
Glycine Max ◽  
Scale Validation ◽  
Soybean Rust ◽  
Phakopsora Pachyrhizi ◽  
Stimulus Response ◽  
Accuracy And Precision ◽  
Rust Severity ◽  
Severity Levels ◽  
Diagrammatic Scale

A diagrammatic scale to assess soybean (Glycine max) rust severity, caused by the fungus Phakopsora pachyrhizi, was developed in this study. Leaflets showing different severity levels were collected for determination of the minimum and maximum severity limits; intermediate levels were determined according to "Weber-Fechner's stimulus-response law". The proposed scale showed the levels of 0.6; 2; 7; 18; 42, and 78.5%. Scale validation was performed by eight raters (four inexperienced and four experienced), who estimated the severity of 44 soybean leaflets showing rust symptoms, with and without the use of the scale. Except for rater number eight, all showed a tendency to overestimate severity without the aid of the diagrammatic scale. With the scale, the raters obtained better accuracy and precision levels, although the tendency to overestimate was maintained. Experienced raters were more accurate and precise than inexperienced raters, and assessment improvements with the use of the scale were more significant for inexperienced raters.

Phakopsora meibomiae (soybean rust).

2021 ◽  
Author(s):  
Keyword(s):  
Glycine Max ◽  
North America ◽  
South America ◽  
Host Range ◽  
Soybean Rust ◽  
Broad Host Range ◽  
Phakopsora Pachyrhizi ◽  
Legume Species ◽  
Asian Species ◽  
The World

Abstract P. meibomiae is a rust native to the tropical and subtropical regions of the Americas that has a broad host range among legume species. It infects soyabean (Glycine max), but is less aggressive on that host than the Asian soyabean rust species, Phakopsora pachyrhizi, which has invaded and spread widely throughout the Americas. Due to the fact that the American species has not caused epidemics on soyabean in South America or invaded North America, it can be considered to be much less invasive than the Asian species. Given its broad host range, the possibility exists that strains of P. meibomiae could be a threat to other legumes cultivated in warm parts of the world.

scholarly journals New soybean (Glycine max Fabales, Fabaceae) sources of qualitative genetic resistance to Asian soybean rust caused by Phakopsora pachyrhizi (Uredinales, Phakopsoraceae)

2008 ◽  
Vol 31 (2) ◽  
pp. 505-511 ◽  
Author(s):  
Pedro Henrique Braga Pierozzi ◽  
Aliny Simony Ribeiro ◽  
José Ubirajara Vieira Moreira ◽  
Larissa Di Cássia Laperuta ◽  
Breno Francovig Rachid ◽  
...  
Keyword(s):  
Glycine Max ◽  
Genetic Resistance ◽  
Soybean Rust ◽  
Phakopsora Pachyrhizi ◽  
Asian Soybean Rust

scholarly journals Prediction of Short-Distance Aerial Movement of Phakopsora pachyrhizi Urediniospores Using Machine Learning

2017 ◽  
Vol 107 (10) ◽  
pp. 1187-1198 ◽  
Author(s):  
L. Wen ◽  
C. R. Bowen ◽  
G. L. Hartman
Keyword(s):  
Machine Learning ◽  
Random Forest ◽  
Short Distance ◽  
Soybean Rust ◽  
Machine Learning Techniques ◽  
Phakopsora Pachyrhizi ◽  
Primary Means ◽  
Soybean Plants ◽  
Selection Operator ◽  
Active Trap

Dispersal of urediniospores by wind is the primary means of spread for Phakopsora pachyrhizi, the cause of soybean rust. Our research focused on the short-distance movement of urediniospores from within the soybean canopy and up to 61 m from field-grown rust-infected soybean plants. Environmental variables were used to develop and compare models including the least absolute shrinkage and selection operator regression, zero-inflated Poisson/regular Poisson regression, random forest, and neural network to describe deposition of urediniospores collected in passive and active traps. All four models identified distance of trap from source, humidity, temperature, wind direction, and wind speed as the five most important variables influencing short-distance movement of urediniospores. The random forest model provided the best predictions, explaining 76.1 and 86.8% of the total variation in the passive- and active-trap datasets, respectively. The prediction accuracy based on the correlation coefficient (r) between predicted values and the true values were 0.83 (P < 0.0001) and 0.94 (P < 0.0001) for the passive and active trap datasets, respectively. Overall, multiple machine learning techniques identified the most important variables to make the most accurate predictions of movement of P. pachyrhizi urediniospores short-distance.

scholarly journals Transcriptome analyses and virus induced gene silencing identify genes in the Rpp4-mediated Asian soybean rust resistance pathway

2013 ◽  
Vol 40 (10) ◽  
pp. 1029 ◽  
Author(s):  
Aguida M. A. P. Morales ◽  
Jamie A. O'Rourke ◽  
Martijn van de Mortel ◽  
Katherine T. Scheider ◽  
Timothy J. Bancroft ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factors ◽  
Gene Silencing ◽  
Differentially Expressed ◽  
Soybean Rust ◽  
Phakopsora Pachyrhizi ◽  
R Gene ◽  
Virus Induced Gene Silencing ◽  
Asian Soybean Rust ◽  
Defence Responses

Rpp4 (Resistance to Phakopsora pachyrhizi 4) confers resistance to Phakopsora pachyrhizi Sydow, the causal agent of Asian soybean rust (ASR). By combining expression profiling and virus induced gene silencing (VIGS), we are developing a genetic framework for Rpp4-mediated resistance. We measured gene expression in mock-inoculated and P. pachyrhizi-infected leaves of resistant soybean accession PI459025B (Rpp4) and the susceptible cultivar (Williams 82) across a 12-day time course. Unexpectedly, two biphasic responses were identified. In the incompatible reaction, genes induced at 12 h after infection (hai) were not differentially expressed at 24 hai, but were induced at 72 hai. In contrast, genes repressed at 12 hai were not differentially expressed from 24 to 144 hai, but were repressed 216 hai and later. To differentiate between basal and resistance-gene (R-gene) mediated defence responses, we compared gene expression in Rpp4-silenced and empty vector-treated PI459025B plants 14 days after infection (dai) with P. pachyrhizi. This identified genes, including transcription factors, whose differential expression is dependent upon Rpp4. To identify differentially expressed genes conserved across multiple P. pachyrhizi resistance pathways, Rpp4 expression datasets were compared with microarray data previously generated for Rpp2 and Rpp3-mediated defence responses. Fourteen transcription factors common to all resistant and susceptible responses were identified, as well as fourteen transcription factors unique to R-gene-mediated resistance responses. These genes are targets for future P. pachyrhizi resistance research.

scholarly journals Pathogenic Variation of Phakopsora pachyrhizi Isolates on Soybean in the United States from 2006 to 2009

Plant Disease ◽  
2012 ◽  
Vol 96 (1) ◽  
pp. 75-81 ◽  
Author(s):  
M. Twizeyimana ◽  
G. L. Hartman
Keyword(s):  
United States ◽  
Resistance Genes ◽  
The United States ◽  
Soybean Rust ◽  
Phakopsora Pachyrhizi ◽  
Soybean Genotype ◽  
Pathogenic Variation ◽  
Differential Set ◽  
Soybean Genotypes ◽  
Soybean Leaves

The introduction of Phakopsora pachyrhizi, the cause of soybean rust, into the United States is a classic case of a pathogen introduction that became established in a new geographical region overwintering on a perennial host (kudzu, Pueraria lobata). The objective of our study was to classify the pathogenic variation of P. pachyrhizi isolates collected in the United States, and to determine the spatial and temporal associations. In total, 72 isolates of P. pachyrhizi collected from infected kudzu and soybean leaves in the United States were purified, then established and increased on detached soybean leaves. These isolates were tested for virulence and aggressiveness on a differential set of soybean genotypes that included six genotypes with known resistance genes (Rpp), one resistant genotype without any known characterized resistance gene, and a susceptible genotype. Three pathotypes were identified among the 72 U.S. P. pachyrhizi isolates based on the virulence of these isolates on the genotypes in the differential set. Six aggressiveness groups were established based on sporulating-uredinia production recorded for each isolate on each soybean genotype. All three pathotypes and all six aggressiveness groups were found in isolates collected from the southern region and from both hosts (kudzu or soybean) in 2008. Shannon's index based on the number of pathotypes indicated that isolates from the South region were more diverse (H = 0.83) compared with the isolates collected in other regions. This study establishes a baseline of pathogenic variation of P. pachyrhizi in the United States that can be further compared with variation reported in other regions of the world and in future studies that monitor P. pachyrhizi virulence in association to deployment of rust resistance genes.

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