scholarly journals Resistance to Boscalid, Fluopyram and Fluxapyroxad in Blumeriella jaapii from Michigan (U.S.A.): Molecular Characterization and Assessment of Practical Resistance in Commercial Cherry Orchards

2021 ◽  
Vol 9 (11) ◽  
pp. 2198
Author(s):  
Jacqueline Gleason ◽  
Jingyu Peng ◽  
Tyre J. Proffer ◽  
Suzanne M. Slack ◽  
Cory A. Outwater ◽  
...  
Keyword(s):  
Leaf Spot ◽  
Target Genes ◽  
Leaf Spot Disease ◽  
Tart Cherry ◽  
Blumeriella Jaapii ◽  
The Past ◽  
Quinone Outside Inhibitor ◽  
Cherry Leaf Spot ◽  
Time Period ◽  
Succinate Dehydrogenase Inhibitor

Management of cherry leaf spot disease, caused by the fungus Blumeriella jaapii, with succinate dehydrogenase inhibitor (SDHI) fungicides has been ongoing in Michigan tart cherry orchards for the past 17 years. After boscalid-resistant B. jaapii were first isolated from commercial orchards in 2010, premixes of SDHI fungicides fluopyram or fluxapyroxad with a quinone outside inhibitor were registered in 2012. Here, we report widespread resistance to fluopyram (FluoR), fluxapyroxad (FluxR), and boscalid (BoscR) in commercial orchard populations of B. jaapii in Michigan from surveys conducted between 2016 and 2019. A total of 26% of 1610 isolates from the 2016–2017 surveys exhibited the fully-resistant BoscR FluoR FluxR phenotype and only 7% were sensitive to all three SDHIs. Practical resistance to fluopyram and fluxapyroxad was detected in 29 of 35 and 14 of 35 commercial tart cherry orchards, respectively, in surveys conducted in 2018 and 2019. Sequencing of the SdhB, SdhC, and SdhD target genes from 22 isolates with varying resistance phenotypes showed that BoscS FluoR FluxS isolates harbored either an I262V substitution in SdhB or an S84L substitution in SdhC. BoscR FluoR FluxR isolates harbored an N86S substitution in SdhC, or contained the N86S substitution with the additional I262V substitution in SdhB. One BoscR FluoR FluxR isolate contained both the I262V substitution in SdhB and the S84L substitution in SdhC. These mutational analyses suggest that BoscR FluoR FluxR isolates evolved from fully sensitive BoscS, FluoS, FluxS isolates in the population and not from boscalid-resistant isolates that were prevalent in the 2010–2012 time period.

scholarly journals Effects of Cherry Leaf Spot on Photosynthesis in Tart Cherry ‘Montmorency’ Foliage

2012 ◽  
Vol 102 (7) ◽  
pp. 656-661 ◽  
Author(s):  
B. R. Gruber ◽  
E. L. Kruger ◽  
P. S. McManus
Keyword(s):  
Leaf Spot ◽  
Leaf Spot Disease ◽  
Tart Cherry ◽  
Blumeriella Jaapii ◽  
Leaf Physiology ◽  
Cherry Leaf Spot ◽  
Leaf Level ◽  
New Perspective ◽  
Serious Disease ◽  
First Time

Results described here span a total of three field seasons and quantitatively depict the effects of an economically important fungal pathogen (Blumeriella jaapii) on tart cherry (Prunus cerasus ‘Montmorency’) leaf physiology. For the first time, leaf photosynthesis, stomatal conductance (gs), maximum ribulose-1,5-bisphosphate carboxylation rate (Vcmax), and maximum electron transport (Jmax) were measured as functions of visible cherry leaf spot disease (CLS) severity. Defined as the proportion of chlorotic and necrotic tissue per leaf, CLS severity was estimated from leaves of mature ‘Montmorency’ trees in 2007, 2008, and 2009. Briefly, as visible disease severity increased, all of the leaf-level physiological parameters decreased significantly (P < 0.01) and disproportionately. Thus, the effects of visible symptoms on leaf photosynthetic metabolic function encroached upon asymptomatic tissue as well. Impairment of photosynthetic metabolism in ‘Montmorency’ tart cherry leaves due to CLS appears to be mediated through disproportionately large perturbations in gs, Vcmax, and Jmax. These findings offer a new perspective on the amount of damage that this serious disease can inflict.

scholarly journals Boscalid Resistance in Blumeriella jaapii: Distribution, Effect on Field Efficacy, and Molecular Characterization

Plant Disease ◽  
2019 ◽  
Vol 103 (6) ◽  
pp. 1112-1118 ◽  
Author(s):  
Cory A. Outwater ◽  
Tyre J. Proffer ◽  
Nikki L. Rothwell ◽  
Jingyu Peng ◽  
George W. Sundin
Keyword(s):  
Field Trials ◽  
Phytopathogenic Fungi ◽  
Current Season ◽  
Slow Growth Rate ◽  
Blumeriella Jaapii ◽  
Quinone Outside Inhibitor ◽  
Cherry Leaf Spot ◽  
Field Efficacy ◽  
Sdhb Gene ◽  
Succinate Dehydrogenase Inhibitor

Cherry leaf spot (CLS), caused by the fungus Blumeriella jaapii, is a major disease of tart cherry (Prunus cerasus L.) trees, leading to early defoliation that results in uneven ripening and poor fruit quality in the current season, reduced fruit set in the following season, and increased potential for winter injury and tree death. Pristine (BASF Corporation, Research Triangle Park, NC), a commonly used fungicide for CLS management in Michigan, is a premix of boscalid, a succinate dehydrogenase inhibitor, and pyraclostrobin, a quinone outside inhibitor. Reduced efficacy of Pristine for CLS control was observed in field trials and commercial orchards and highlights the importance of fungicide resistance monitoring. A total of 1,189 isolates from 31 commercial orchards in Michigan, 111 isolates from nontreated trees (four locations in Michigan and two locations in Ohio), and 133 isolates from a research orchard were collected during 2010, 2011, and 2012 and assayed on boscalid-amended media at concentrations ranging from 0 to 25 μg ml−1. Because of the very slow growth rate of B. jaapii in culture, we determined the minimum inhibitory concentration (MIC) of boscalid as opposed to the effective concentration that inhibits mycelial growth to 50% of the control. Isolates from nontreated trees had MIC values ranging from 0.1 to 0.5 μg ml−1; the MIC of isolates from commercial orchards ranged from 0.1 to >25 μg ml−1, and isolates from the research orchard ranged from 2.5 to >25 μg ml−1. Isolates with MIC values ≥25 μg ml−1 were considered boscalid resistant and comprised 0% of the nontreated isolates, 30.4% of the commercial isolates, and 42.1% of the research orchard isolates. Sequencing of the sdhB gene of resistant isolates led to the detection of the amino acid mutation H260R, which is known to confer boscalid resistance in other phytopathogenic fungi. Our results indicate that the occurrence of the H260R mutation in Michigan populations of B. jaapii is correlated with the reduction in sensitivity to boscalid observed in commercial orchards.

scholarly journals Effects of Copper-Based Fungicides on Foliar Gas Exchange in Tart Cherry

Plant Disease ◽  
2009 ◽  
Vol 93 (5) ◽  
pp. 512-518 ◽  
Author(s):  
B. R. Gruber ◽  
L. R. R. Davies ◽  
E. L. Kruger ◽  
P. S. McManus
Keyword(s):  
Gas Exchange ◽  
Late Summer ◽  
The United States ◽  
Leaf Spot Disease ◽  
Tart Cherry ◽  
Mature Trees ◽  
Blumeriella Jaapii ◽  
Cherry Leaf Spot ◽  
Leaf Surface Area ◽  
Old Trees

In the Great Lakes region of the United States, cherry growers are poised to re-adopt copper-based fungicides to manage cherry leaf spot disease (CLS), caused by Blumeriella jaapii. However, application of copper is often associated with leaf bronzing. In growth chamber experiments, bronzing was observed on foliage of tart cherry (Prunus cerasus ‘Montmorency’) seedlings 1 week following application of a copper-based fungicide, only when leaves were also exposed to nightly dew. In potted, 1-year-old trees outdoors, light-saturated rates of net CO2 assimilation (A) and stomatal conductance (gs) were not affected by treatment with copper sulfate, chlorothalonil, tebuconazole, or trifloxystrobin compared to a nonsprayed control. In 2005 and 2006, A and gs were measured during late summer on leaves of mature trees in an orchard subjected to the following fungicide programs: synthetic fungicides only; synthetic fungicides integrated with copper-based fungicides; or not sprayed. Bronzing symptoms were observed on trees sprayed with copper. Regression analysis revealed that neither A nor gs decreased as leaf surface area affected by bronzing increased (R2 = 0.004, P = 0.80 and R2 = 0.006, P = 0.74, respectively). Leaf bronzing associated with application of copper-based fungicides may therefore be inconsequential to foliar gas exchange in tart cherry during late summer.

scholarly journals A Copper-based Fungicide Has Minimal Effects on Tart Cherry Fruit Quantity and Quality

HortScience ◽  
2010 ◽  
Vol 45 (1) ◽  
pp. 48-53 ◽  
Author(s):  
Barrett R. Gruber ◽  
Libby R.R. Davies ◽  
Patricia S. McManus
Keyword(s):  
Repeated Measures ◽  
Soluble Solids ◽  
Leaf Spot Disease ◽  
Tart Cherry ◽  
Fresh Weight ◽  
Blumeriella Jaapii ◽  
Program Effect ◽  
Cherry Leaf Spot ◽  
Solids Concentration ◽  
Collection Date

Copper-based fungicides are effective for managing cherry leaf spot disease incited by Blumeriella jaapii (Rehm) Arx. However, their application has been associated with bronzing discoloration of tart cherry (Prunus cerasus L.) foliage. This work explored the consequences of foliar applications of a copper-based fungicide for tart cherry fruit quantity and quality. ‘Montmorency’ tart cherry trees were subjected to one of the following fungicide programs in 2007, 2008, and 2009: synthetic fungicides only, synthetic fungicides integrated with a copper-based fungicide, or not sprayed. Each year, the number of fruits per shoot and fruit fresh weight and soluble solids concentration (SSC) were measured three to six times during drupe development. Repeated measures indicated no collection date × fungicide program effect on the mean number of fruits (P ≥ 0.48) and SSC (P ≥ 0.14) in all years or on fresh weight in 2008 and 2009 (P ≥ 0.58). There was a collection date × fungicide program effect (P = 0.02) on mean fresh weight in 2007. On 6 July 2007, trees assigned to the integrated copper program were observed having 23% and 27% lower fruit fresh weights than trees assigned to the nonsprayed and synthetic programs, respectively. However, pairwise comparisons indicated no difference in fresh weight between the integrated copper and the nonsprayed programs (P = 0.26) and no difference between the integrated copper and synthetic programs (P = 0.25) on the final collection date of 2007. In 2007, fresh weight decreased slightly (slope = –0.08, P = 0.05) as leaf bronzing severity increased, whereas SSC increased slightly (slope = 0.31, P = 0.06). In 2008 and 2009, there was no relationship between bronzing severity and fresh weight or SSC (P ≥ 0.34). These results indicate that applied copper does not lead to fewer fruits per shoot or reductions in fresh weight or SSC of mature fruit and that the observed range of leaf bronzing severity had little to no influence on fresh weight and SSC.

scholarly journals Draft Genome Sequence Resource for Blumeriella jaapii, the Cherry Leaf Spot Pathogen

2020 ◽  
Vol 110 (9) ◽  
pp. 1507-1510
Author(s):  
Jingyu Peng ◽  
J. Alejandro Rojas ◽  
Hyunkyu Sang ◽  
Tyre J. Proffer ◽  
Cory A. Outwater ◽  
...  
Keyword(s):  
Leaf Spot ◽  
Draft Genome ◽  
Resistance Mechanisms ◽  
Phytopathogenic Fungi ◽  
Blumeriella Jaapii ◽  
Cherry Leaf Spot ◽  
Long Reads ◽  
The Family ◽  
Sterol Demethylation Inhibitors ◽  
High Quality Genome

Blumeriella jaapii is the causal agent of cherry leaf spot (CLS), the most important disease of tart cherry in the Midwestern United States. Infection of leaves by B. jaapii leads to premature defoliation, which places trees at heightened risk of winter injury and death. Current management of CLS relies primarily on the application of three important fungicide classes, quinone outside inhibitors, sterol demethylation inhibitors, and succinate dehydrogenase inhibitors. Here, we present the first high-quality genome of B. jaapii through a hybrid assembly of PacBio long reads and Illumina short reads. The assembled draft genome of B. jaapii is 47.4 Mb and consists of 95 contigs with a N50 value of 1.5 Mb. The genomic information of B. jaapii, representing the most complete sequenced genome of the family Dermateaceae (Ascomycota) to date, provides a valuable resource for identifying fungicide resistance mechanisms of this pathogen and expands our knowledge of the phytopathogenic fungi in this family.

scholarly journals Overexpression of the 14α-Demethylase Target Gene (CYP51) Mediates Fungicide Resistance in Blumeriella jaapii

2006 ◽  
Vol 72 (4) ◽  
pp. 2581-2585 ◽  
Author(s):  
Zhonghua Ma ◽  
Tyre J. Proffer ◽  
Janette L. Jacobs ◽  
George W. Sundin
Keyword(s):  
Leaf Spot ◽  
Fungicide Resistance ◽  
Target Gene ◽  
Direct Repeat ◽  
Efflux Pumps ◽  
Blumeriella Jaapii ◽  
Cherry Leaf Spot ◽  
Dmi Fungicides ◽  
Long Interspersed Nuclear Element ◽  
Demethylation Inhibitor

ABSTRACT Sterol demethylation inhibitor (DMI) fungicides are widely used to control fungi pathogenic to humans and plants. Resistance to DMIs is mediated either through alterations in the structure of the target enzyme CYP51 (encoding 14α-demethylase), through increased expression of the CYP51 gene, or through increased expression of efflux pumps. We found that CYP51 expression in DMI-resistant (DMIR) isolates of the cherry leaf spot pathogen Blumeriella jaapii was increased 5- to 12-fold compared to that in DMI-sensitive (DMIS) isolates. Analysis of sequences upstream of CYP51 in 59 DMIR isolates revealed that various forms of a truncated non-long terminal direct repeat long interspersed nuclear element retrotransposon were present in all instances. Similar inserts upstream of CYP51 were not present in any of 22 DMIS isolates examined.

Perpetuation of Cherry Leaf Spot Disease in Ornamental Cherry

2014 ◽  
Vol 163 (3) ◽  
pp. 194-201
Author(s):  
Jacqueline Joshua ◽  
Margaret T. Mmbaga
Keyword(s):  
Leaf Spot ◽  
Leaf Spot Disease ◽  
Spot Disease ◽  
Cherry Leaf Spot

scholarly journals Some aspects of disease management of cherry leaf spot (Blumeriella jaapii) with special reference to pesticide use

2010 ◽  
Vol 16 (1) ◽  
Author(s):  
I. J. Holb ◽  
P. Lakatos ◽  
F. Abonyi
Keyword(s):  
Disease Management ◽  
Special Reference ◽  
Leaf Spot ◽  
Chemical Control ◽  
Pesticide Use ◽  
Control Approach ◽  
Blumeriella Jaapii ◽  
Cherry Leaf Spot ◽  
Sterol Demethylation Inhibitors ◽  
Fallen Leaves

In this review, some aspects of disease management of cherry leaf spot (Blumeriella jaapii) are summarised with special reference to pesticide use. In the first part of the review, we show the non-chemical control approach (e. g. removal of fallen leaves, planting resistant cultivar) against leaf spot. In the second part of the review, the effect of pesticides including fertilizers (urea) and fungicides on cherry leaf spot are discussed. Special attention are given to the fungicides of copper, dodine, captafol, captan, benomil, chlorothalonil, sterol demethylation inhibitors (e.g. fenarimol, fenbuconazole, myclobutanil, tebuconazole), and strobilurins about their effectiveness against cherry leaf spot. In the final part of the review, possibilities of cherry leaf spot control are discussed in integrated and organic cherry orchards.

Cercospora nicotianae Isolates from Flue-Cured Tobacco in North Carolina Found with G143A and F129L Mutations in Cytochrome b Gene

2020 ◽  
Vol 21 (4) ◽  
pp. 288-290
Author(s):  
Andrew Ernst ◽  
Lindsey Thiessen
Keyword(s):  
North Carolina ◽  
Leaf Spot ◽  
Fungicide Resistance ◽  
Single Point ◽  
Leaf Spot Disease ◽  
Single Point Mutation ◽  
Resistance Mutations ◽  
Quinone Outside Inhibitor ◽  
Frogeye Leaf Spot ◽  
Qoi Resistance

Frogeye leaf spot of tobacco caused by Cercospora nicotianae (Ellis & Everhart) is a widespread disease of cultivated tobacco. Recently, flue-cured tobacco producers in North Carolina reported losses due to frogeye leaf spot disease despite the use of strobilurin fungicides. Isolates (n = 4) were obtained in 2018 from affected tobacco leaves from Cumberland, Lenoir, and Nash counties. In 2019, isolates (n = 28) were collected from a field in Wilson county. After sequencing the cytb region of 32 isolates, 30 contained a single point mutation conferring a G143A or F129L amino acid change that resulted in quinone outside inhibitor (QoI) fungicide resistance. Although these resistance mutations have been found in air-cured tobacco in Kentucky, to the best of our knowledge, the present study is the first to report QoI resistance mutations in C. nicotianae populations in flue-cured tobacco and a first report in North Carolina.

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