scholarly journals Fungicide resistance in Cercospora species causing cercospora leaf blight and purple seed stain of soybean in Argentina

2020 ◽  
Vol 69 (9) ◽  
pp. 1678-1694 ◽  
Author(s):  
Francisco J. Sautua ◽  
Vinson P. Doyle ◽  
Paul P. Price ◽  
Alejandro Porfiri ◽  
Paula Fernandez ◽  
...  
Keyword(s):  
Fungicide Resistance ◽  
Leaf Blight ◽  
Purple Seed Stain

scholarly journals Fungicide Resistance in Cercospora kikuchii, a Soybean Pathogen

Plant Disease ◽  
2015 ◽  
Vol 99 (11) ◽  
pp. 1596-1603 ◽  
Author(s):  
Paul P. Price ◽  
Myra A. Purvis ◽  
Guohong Cai ◽  
Guy B. Padgett ◽  
Clark L. Robertson ◽  
...  
Keyword(s):  
Fungicide Resistance ◽  
Radial Growth ◽  
Management Strategies ◽  
Leaf Blight ◽  
Cross Resistance ◽  
Multiple Resistance ◽  
Cercospora Kikuchii ◽  
Qoi Fungicides ◽  
Quinone Outside Inhibitor ◽  
Purple Seed Stain

Isolates of Cercospora kikuchii, a soybean (Glycine max) pathogen causing Cercospora leaf blight and purple seed stain, were tested to determine baseline sensitivities (n = 50) to selected quinone outside inhibitor (QoI) fungicides by conducting radial growth assays on fungicide-amended media. Baseline effective fungicide concentration to inhibit 50% of fungal radial growth (EC50) values were compared with EC50 values for isolates collected in 2011 (n = 50), 2012 (n = 50), and 2013 (n = 36) throughout soybean-producing areas in Louisiana. Median EC50 values for isolates subjected to QoI fungicides were significantly (P = 0.05) higher across all 3 years. Cross-resistance to QoI fungicides was observed in resistant isolates collected in 2011 to 2013. Discriminatory doses were developed for QoI fungicides to distinguish between sensitive and resistant isolates. On average, 89% of all isolates screened in 2011 to 2013 were resistant to QoI fungicides. At a discriminatory dose of thiophanate methyl (TM), a methyl benzimidazole carbamate (MBC) fungicide, at 5 μg/ml, resistance was detected in the 2000, 2011, 2012, and 2013 collections at 23, 38, 29, and 36%, respectively. Isolates exhibiting multiple resistance to QoI fungicides and TM also were detected in 2011, 2012, and 2013 at frequencies of 34, 26, and 31%, respectively. Based on these results, Cercospora leaf blight management strategies in Louisiana using solo applications of QoI or MBC fungicides in soybean should be reconsidered.

The G143A Mutation is Responsible for Strobilurin Fungicide Resistance in Cercospora cf. flagellaris, a Leaf Blight and Purple Seed Stain Pathogen of Louisiana Soybean

2016 ◽  
Vol 17 (3) ◽  
pp. 197-197 ◽  
Author(s):  
Sebastian Albu ◽  
Trey Price ◽  
Vinson Doyle ◽  
Boyd Padgett ◽  
Ray Schneider
Keyword(s):  
Cytochrome B ◽  
Mississippi River ◽  
Fungicide Resistance ◽  
Radial Growth ◽  
Leaf Blight ◽  
Cytochrome B Gene ◽  
Pathogen Population ◽  
Lower Mississippi River ◽  
Strobilurin Fungicide ◽  
Purple Seed Stain

Cercospora leaf blight and purple seed stain are economically important diseases of soybean throughout the Lower Mississippi River Valley and Gulf South USA. Fungicide resistance was documented in Louisiana in the pathogen population using radial growth assays. Using some of the same isolates, a portion of the cytochrome b gene was sequenced. The G143A mutation was found in resistant isolates, and results correlated with radial growth assays 97% of the time. Accepted for publication 1 September 2016.

scholarly journals Growth Potential of Different Fungicide Resistant Alternaria solani Isolates of Tomato Leaf Blight Pathogen, under In Vitro, in the Presence of Different Fungicide, Growth Temperature and pH Ion Concentration

2020 ◽  
Vol 2 (5) ◽  
Author(s):  
V. A. Chavan ◽  
S. G. Borkar ◽  
Nivedita A Kadam
Keyword(s):  
Growth Rate ◽  
Fungicide Resistance ◽  
Plant Disease ◽  
Plant Pathogens ◽  
Alternaria Solani ◽  
Leaf Blight ◽  
Growth Potential ◽  
Resistant Isolate ◽  
Cross Resistance

Evolution of fungicide resistance in plant pathogens and cross resistance to other fungicides in such pathogens is one of major concerns in sustainable plant disease management. Frequent and unwarranted use of fungicides to control plant diseases not only pollute the earth soil and environment, but also causes the development of fungicide resistance in the plant pathogens, which makes it difficult to manage the plant disease. In India, particularly in western Maharashtra, Alternaria leaf blight pathogen of tomato developed resistance and cross resistance to various fungicides. How these fungicide resistant isolates grow in the different fungicidal environment is reported in the present investigation. Eight different fungicide resistant isolates of Alternaria solani responsible for causing leaf blight in tomato crop were tested for their growth potential, under in vitro condition, on the potato-dextrose-agar(PDA) growth media amended with different fungicides viz. Dithane M-45, Blitox, Kavach, Ridomil, Nativo, Bavistin, Captaf and Score. Different fungicide resistant isolates showed different pattern of growth i.e. complete inhibition of growth, reduced growth or enhancement of growth on different fungicide amended PDA media. The growth of Dithane M-45 resistant isolate was enhanced by fungicide Kavach and Bavistin while reduced by fungicide Blitox. The growth of this fungicide resistant isolate was completely inhibited by fungicide Ridomil, Nativo, Captaf and Score. The maximum enhancement of growth was for Nativo resistant isolate to Bavistin amended PDA media. Bavistin resistant isolate had decreased growth on all fungicides amended PDA media. The minimum reduction in growth was recorded for Kavach resistant isolate on Dithane M-45 fungicide amended PDA media. The growth rate (cm/day) of these fungicide resistant isolates was maximum at 220C temperature as compared to 25 and 300C temperature on the routine PDA growth medium. Captaf resistant isolate produced more growth followed by Nativo, Dithane M-45 and score resistant isolate. The minimum growth was observed for Blitox resistant isolate. As the temperature increases, the growth rate decreased. The growth of fungicide resistant isolates was favored by neutral pH of 7.0 and decreased toward the acidic and alkaline condition. Captaf resistant isolate produced more growth followed by Nativo and score resistant isolates. The minimum growth was produced by Blitox resistant isolate. More growth of fungicide resistant Alternaria isolate means production of more inoculum for disease initiation and spread which is favored at 22 °C temperature and further indicate which fungicide should be used to restrict/manage the growth of particular Alternaria fungicide resistant isolate.

scholarly journals Cercospora cf. flagellaris and Cercospora cf. sigesbeckiae Are Associated with Cercospora Leaf Blight and Purple Seed Stain on Soybean in North America

2016 ◽  
Vol 106 (11) ◽  
pp. 1376-1385 ◽  
Author(s):  
S. Albu ◽  
R. W. Schneider ◽  
P. P. Price ◽  
V. P. Doyle
Keyword(s):  
United States ◽  
Sexual Reproduction ◽  
Mating Type ◽  
Phylogenetic Signal ◽  
Phylogenetic Analyses ◽  
The United States ◽  
Leaf Blight ◽  
Internal Transcribed Spacer Region ◽  
Type Locus ◽  
Purple Seed Stain

Cercospora kikuchii has long been considered the causal agent of Cercospora leaf blight (CLB) and purple seed stain (PSS) on soybean, but a recent study found C. cf. flagellaris associated with CLB and PSS in Arkansas (United States) and Argentina. Here, we provide a broader perspective on the distribution of C. cf. flagellaris on soybean and alternate hosts within the United States (Arkansas, Louisiana, Mississippi, Missouri, and Kansas). We used a multilocus phylogenetic approach with data from actin, calmodulin, translation elongation factor 1-α, histone 3, the internal transcribed spacer region of rDNA and the mating-type locus to determine that two species, C. cf. flagellaris (200 of 205 isolates) and C. cf. sigesbeckiae (five of 205 isolates), are associated with CLB and PSS in the United States. In our phylogenetic analyses, species-level lineages were generally well-supported, though deeper-level evolutionary relationships remained unresolved, indicating that these genes do not possess sufficient phylogenetic signal to resolve the evolutionary history of Cercospora. We also investigated the potential for sexual reproduction in C. cf. flagellaris in Louisiana by determining the frequency of MAT1-1/MAT1-2 mating-type idiomorphs within the Louisiana population of C. cf. flagellaris. Though the MAT 1-2 idiomorph was significantly more common in our collection, the presence of both mating types suggests the potential for sexual reproduction exists.

Multi-host species of Cercospora are associated with Cercospora leaf blight and purple seed stain of soybean

2018 ◽  
Vol 43 (2) ◽  
pp. 170-177
Author(s):  
L. L. Borges ◽  
T. F. Ferreira ◽  
M. G. Lana ◽  
I. D. Caliman ◽  
B. H. Bluhm ◽  
...  
Keyword(s):  
Host Species ◽  
Leaf Blight ◽  
Purple Seed Stain

scholarly journals Genome Resource for Two Stemphylium vesicarium Isolates Causing Stemphylium Leaf Blight of Onion in New York

2020 ◽  
Vol 33 (4) ◽  
pp. 562-564
Author(s):  
Sandeep Sharma ◽  
Frank S. Hay ◽  
Sarah J. Pethybridge
Keyword(s):  
New York ◽  
Comparative Genomics ◽  
Fungicide Resistance ◽  
Population Biology ◽  
Management Strategies ◽  
Leaf Blight ◽  
The Other ◽  
Brown Spot ◽  
Stemphylium Vesicarium ◽  
Genomic Studies

Stemphylium leaf blight caused by Stemphylium vesicarium was recently identified as an emerging disease and dominant in the foliar disease complex affecting onion in New York. Here, we report the genomes of two isolates of S. vesicarium, On16-63 and On16-391. The availability of the genomes will accelerate genomic studies of S. vesicarium, including population biology, sexual reproduction, and fungicide resistance. Additionally, comparative genomics with the other published genome of S. vesicarium causing brown spot of pear will help understand pathogen biology and underpin the development of management strategies for this disease.

scholarly journals Draft genome sequence data of Cercospora kikuchii, a causal agent of Cercospora leaf blight and purple seed stain of soybeans

Data in Brief ◽  
2019 ◽  
Vol 27 ◽  
pp. 104693 ◽  
Author(s):  
Francisco J. Sautua ◽  
Sergio A. Gonzalez ◽  
Vinson P. Doyle ◽  
Marcelo F. Berretta ◽  
Manuela Gordó ◽  
...  
Keyword(s):  
Genome Sequence ◽  
Sequence Data ◽  
Draft Genome ◽  
Leaf Blight ◽  
Causal Agent ◽  
Draft Genome Sequence ◽  
Cercospora Kikuchii ◽  
Genome Sequence Data ◽  
Purple Seed Stain
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