scholarly journals Integration of Copper-Based and Reduced-Risk Fungicides for Control of Blumeriella jaapii on Sour Cherry

Plant Disease ◽  
2007 ◽  
Vol 91 (3) ◽  
pp. 294-300 ◽  
Author(s):  
Patricia S. McManus ◽  
Tyre J. Proffer ◽  
Raffaele Berardi ◽  
Barrett R. Gruber ◽  
James E. Nugent ◽  
...  
Keyword(s):  
Sour Cherry ◽  
Field Trials ◽  
Study Strategies ◽  
Blumeriella Jaapii ◽  
Cherry Leaf Spot ◽  
Dmi Fungicides ◽  
Resistant Strains ◽  
Protection Against Infection ◽  
Disease Pressure

Practical resistance to sterol demethylation inhibitor (DMI) fungicides among populations of Blumeriella jaapii, the cherry leaf spot (CLS) pathogen, was documented in 2005. In the present study, strategies to reduce selection for DMI-resistant strains of B. jaapii and adapt to possible restrictions on the use of chlorothalonil are described. Ten field trials were conducted on the sour cherry cultivars Balaton and Montmorency to test the efficacy of integrating respiration-inhibitor and copper-based fungicides into spray programs. Programs that included up to three sprays of copper-based fungicides were among the most effective for controlling CLS, although leaf phy-totoxicity was sometimes observed. Under high disease pressure, eliminating chlorothalonil compromised CLS control. ‘Balaton’ and ‘Montmorency’ did not differ in the percentage of leaves with CLS or defoliation resulting from CLS. The physical modes of action of representative DMI, QoI, and copper-based fungicides were evaluated in a leaf disk assay. Trifloxystrobin, a QoI fungicide, provided the best protection against infection by B. jaapii. All fungicides were more effective than water when applied 46 h postinfection, although differences were not statistically significant in one of two trials. Tebuconazole, a DMI, was the only fungicide that was more effective than water in preventing resporulation from existing lesions in both trials. Isolates of B. jaapii, which varied in DMI-sensitivity, all were sensitive to copper in vitro.

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.

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 Screening Cherry Germ Plasm for Resistance to Leaf Spot

Plant Disease ◽  
2003 ◽  
Vol 87 (5) ◽  
pp. 471-477 ◽  
Author(s):  
Phillip S. Wharton ◽  
Amy Iezzoni ◽  
Alan L. Jones
Keyword(s):  
Leaf Spot ◽  
Germ Plasm ◽  
Sour Cherry ◽  
Prunus Cerasus ◽  
Prunus Species ◽  
Disease Symptoms ◽  
Blumeriella Jaapii ◽  
Detached Leaf ◽  
Cherry Leaf Spot ◽  
White Spots

A detached leaf disk assay was developed for screening sour cherry (Prunus cerasus) cultivars for resistance to cherry leaf spot (Blumeriella jaapii). This assay was used to characterize the events occurring in cv. Montmorency (susceptible) and cv. GiSelA 6 [GI 148-1] (resistant) host-pathogen interactions, and to develop a disease scoring scheme to categorize disease severity in sour cherry trees. Forty-three seedlings grown from seeds collected in Russia were screened for resistance using the scoring scheme. Cross infection studies were also carried out with leaf spot isolates from four other Prunus species. These studies were made possible by the development of a new method of culturing B. jaapii isolates, using cherry fruit agar. This method enabled large amounts of inoculum to be produced within 2 weeks rather than a couple of months as required previously. In ‘Montmorency’, disease symptoms were first observed 4 days postinoculation (dpi), with the appearance of small white spots on the undersides of inoculated leaves. These spots gradually grew, producing erumpent spore masses in acervuli approximately 7 dpi. In ‘GI 148-1’, disease symptoms were also first observed 4 dpi, with the appearance of small transparent lesions. In the majority of cases, these lesions did not increase in size; however, acervuli occasionally were formed approximately 8 dpi. These contained small cirrhi and were often surrounded by an abscission zone. Of the sour cherry seedlings tested, only ‘Almaz’ open pollinated (o.p.) R1(1) was rated as resistant. ‘Almaz’ o.p. R1(1) and ‘GI 148-1’ were also rated as resistant to leaf spot isolates from other Prunus species. These results and the implications for breeding resistant sour cherry cultivars are discussed.

Identification of a Source of Resistance to Cherry Leaf Spot

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 500c-500
Author(s):  
S.L. Downey ◽  
R. Karle ◽  
A.F. Iezzoni ◽  
A.L. Jones
Keyword(s):  
Leaf Spot ◽  
Sour Cherry ◽  
The United States ◽  
Prunus Cerasus ◽  
Triploid Hybrid ◽  
Blumeriella Jaapii ◽  
Cherry Leaf Spot ◽  
Resistant Varieties ◽  
Leaf Drop ◽  
Production Areas

Cherry leaf spot caused by Blumeriella jaapii (Rhem) Arx. is a major fungal disease of sour cherry in most of the world's sour cherry production areas. This fungus causes premature defoliation, which, in conjunction with low temperature winter injury, can result in death of limbs and entire trees. `Montmorency', the only major sour cherry cultivar grown in the United States, is highly susceptible to this fungus and numerous fungicides are required to prevent this disease. In 1996, sour cherry seedlings and GI 148-1, a triploid hybrid developed in Germany from the cross sour cherry (Prunus cerasus Schattenmorelle) × P. canescens (Schmidt and Gruppe 1988 HortScience 23: 112), were inoculated with spores of B. jaapii obtained from infected sour cherry leaves in the orchard. Lesion counts were taken on days 7 and 14 and the number of lesions per cm2 was calculated. This experiment was repeated in 1997, including a full sibling of GI 148-1, GI 148-2. Sour cherry and GI 148-2 were highly susceptible to cherry leaf spot. Within 14 days, these selections exhibited an average of 19.4 and 5.4 necrotic lesions per cm2 respectively, sporulation, chlorosis, and eventually leaf drop. In contrast, GI 148-1 had significantly fewer lesions on average (1.4 lesions per cm2), no apparent sporulation, chlorosis or leaf drop. Different reactions exhibited by siblings GI 148-1 and GI 148-2 suggest that the resistance gene(s) in 148-1 are on the P. canescens chromosome(s), not from the sour cherry parent, and that the P. canescens parent was not homozygous. GI 148-1 is currently being used in a backcross breeding program to develop resistant varieties.

scholarly journals Selection of autochthonous sour cherry (Prunus cerasus L.) genotypes in Feketic region

Genetika ◽  
2012 ◽  
Vol 44 (2) ◽  
pp. 285-297 ◽  
Author(s):  
Sanja Radicevic ◽  
Radosav Cerovic ◽  
Milan Lukic ◽  
Svetlana Paunovic ◽  
Darko Jevremovic ◽  
...  
Keyword(s):  
Sour Cherry ◽  
Brown Rot ◽  
Fruit Weight ◽  
Field Resistance ◽  
Soluble Solids ◽  
Blumeriella Jaapii ◽  
Ripening Time ◽  
Fruit Species ◽  
Cherry Leaf Spot ◽  
Ring Spot

Autochthonous genotypes of fruit species are very important source of genetic variability and valuable material for breeding work. Fruit Research Institute-Cacak has a long tradition of studying autochthonous genotypes of temperate fruits sporadically spread and preserved in some localities in Serbia. Over 2005-2006, the following properties of nine autochthonous sour cherry genotypes grown in Feketic region were investigated: flowering and ripening time, pomological properties, biochemical composition of fruits and field resistance to causal agents of cherry diseases - cherry leaf spot (Blumeriella jaapii (Rehm.) v. Arx.), shot-hole (Clasterosporium carpophilum (L?v.) Aderh.) and brown rot (Monilinia laxa /Ader et Ruhl./ Honey ex Whetz.). The genotypes were tested for the presence of Prune dwarf virus and Prunus necrotic ring spot virus. In majority of genotypes fruits were large, with exceptional organoleptical properties, whereas ripening time was in the first ten or twenty days of June. The highest fruit weight was observed in F-1 genotype (8.1 g). The highest soluble solids and total sugars content were found in F- 4 genotype (17.60% and 14.25%, respectively). As for field resistance to causal agents of diseases and good pomo-technological properties, F-1, F-2, F-3, F-7 and F-8 genotypes were singled out.

scholarly journals Possibilities for reducing fungicide treatments in sour cherry production

2008 ◽  
pp. 3-6
Author(s):  
Maria Borovinova
Keyword(s):  
Pseudomonas Syringae ◽  
Leaf Spot ◽  
Sour Cherry ◽  
Brown Rot ◽  
Early Spring ◽  
Ergosterol Biosynthesis ◽  
Monilinia Fructigena ◽  
Blumeriella Jaapii ◽  
Cherry Leaf Spot ◽  
Ergosterol Biosynthesis Inhibitors

The aim of this study was to investigate the possibilities for reducing fungicide treatments of sour cherry. The study was conducted in fruit bearing sour cherry orchards of the Institute of Agriculture at Kyustendil during 1991-2005. Cherry leaf spot was controlled by postinfection applications of ergosterol biosynthesis inhibitors and dodine. Bacterial canker, brown rot, shot-hole syndrome were controlled by protective treatments with copper-containing fungicides in late autumn and early spring. Insecticide treatments were applied when it was necessary. Blumeriella jaapii is the main pathogen of sour cherry which can be controlled successfully by postinfection treatments. Their number could be reduced in some years. Sprays against leaf spot were effective against other diseases too. Protective treatments against Pseudomonas syringae with copper-containing fungicides were effective against shot-hole syndrome and Monilinia laxa as well as Monilinia fructigena.

scholarly journals Some aspects of reduced disease management against Blumeriella jaapii in sour cherry production

2011 ◽  
Vol 17 (1-2) ◽  
Author(s):  
I. J. Holb ◽  
A. Vámos ◽  
P. Lakatos ◽  
J. M. Gáll ◽  
F. Abonyi
Keyword(s):  
Disease Management ◽  
Leaf Spot ◽  
Sour Cherry ◽  
Blumeriella Jaapii ◽  
Cherry Leaf Spot

The aim of this study was to evaluate the effectiveness of reduced spray programmes against cherry leaf spot in integrated and organic sour cherry orchards. Altogether four spray programmes were performed i) standard integrated: sprays followed by forecasting systems during the season, ii) reduced integrated: sprays followed by forecasting systems but only 75% of the spray numbers used during the season-long spray programme, iii) standard oragnic: sprays applied every 7–14 days during the season and iv) reduced organic: 60 % of the spray numbers used during the season-long spray programme. Our study showed that cherry leaf spot did not increase above 3.1, 7.4, and 8.9% in 2008, 2009, and 2010, respectively, in the integrated orchards. However, leaf spot incidence was above 20% in all years in the organic field. Reduced spray programme did not increase significantly cherry leaf spot incidence in the integrated field in either years. However, leaf spot incidence increased significanly (above 20%) in the reduced spray programme for the organic orchard.

Mechanisms involved in effects of antimicrobial peptides, bactenectins ChBac3.4, ChBac5, and mini-ChBac7.5Nb, on bacterial cells

2017 ◽  
pp. 43-50
Author(s):  
О.В. Шамова ◽  
М.С. Жаркова ◽  
П.М. Копейкин ◽  
Д.С. Орлов ◽  
Е.А. Корнева
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Innate Immunity ◽  
Infectious Diseases ◽  
Metabolic Activity ◽  
Capra Hircus ◽  
Bacterial Cells ◽  
Antibiotic Resistant ◽  
Resistant Strains

Антимикробные пептиды (АМП) системы врожденного иммунитета - соединения, играющие важную роль в патогенезе инфекционных заболеваний, так как обладают свойством инактивировать широкий спектр патогенных бактерий, обеспечивая противомикробную защиту живых организмов. В настоящее время АМП рассматриваются как потенциальные соединения-корректоры инфекционной патологии, вызываемой антибиотикорезистентными бактериями (АБР). Цель данной работы состояла в изученим механизмов антибактериального действия трех пептидов, принадлежащих к семейству бактенецинов - ChBac3.4, ChBac5 и mini-ChBac7.5Nb. Эти химически синтезированные пептиды являются аналогами природных пролин-богатых АМП, обнаруженных в лейкоцитах домашней козы Capra hircus и проявляющих высокую антимикробную активность, в том числе и в отношении грамотрицательных АБР. Методы. Минимальные ингибирующие и минимальные бактерицидные концентрации пептидов (МИК и МБК) определяли методом серийных разведений в жидкой питательной среде с последующим высевом на плотную питательную среду. Эффекты пептидов на проницаемость цитоплазматической мембраны бактерий для хромогенного маркера исследовали с использованием генетически модифицированного штамма Escherichia coli ML35p. Действие бактенецинов на метаболическую активность бактерий изучали с применением маркера резазурина. Результаты. Показано, что все исследованные пептиды проявляют высокую антимикробную активность в отношении Escherichia coli ML35p и антибиотикоустойчивых штаммов Escherichia coli ESBL и Acinetobacter baumannii in vitro, но их действие на бактериальные клетки разное. Использован комплекс методик, позволяющих наблюдать в режиме реального времени динамику действия бактенецинов в различных концентрациях (включая их МИК и МБК) на барьерную функцию цитоплазматической мембраны и на интенсивность метаболизма бактериальных клеток, что дало возможность выявить различия в характере воздействия бактенецинов, отличающихся по структуре молекулы, на исследуемые микроорганизмы. Установлено, что действие каждого из трех исследованных бактенецинов в бактерицидных концентрациях отличается по эффективности нарушения целостности бактериальных мембран и в скорости подавления метаболизма клеток. Заключение. Полученная информация дополнит существующие фундаментальные представления о механизмах действия пролин-богатых пептидов врожденного иммунитета, а также послужит основой для биотехнологических исследований, направленных на разработку на базе этих соединений новых антибиотических препаратов для коррекции инфекционных заболеваний, вызываемых АБР и являющимися причинами тяжелых внутрибольничных инфекций. Antimicrobial peptides (AMPs) of the innate immunity are compounds that play an important role in pathogenesis of infectious diseases due to their ability to inactivate a broad array of pathogenic bacteria, thereby providing anti-microbial host defense. AMPs are currently considered promising compounds for treatment of infectious diseases caused by antibiotic-resistant bacteria. The aim of this study was to investigate molecular mechanisms of the antibacterial action of three peptides from the bactenecin family, ChBac3.4, ChBac5, and mini-ChBac7.5Nb. These chemically synthesized peptides are analogues of natural proline-rich AMPs previously discovered by the authors of the present study in leukocytes of the domestic goat, Capra hircus. These peptides exhibit a high antimicrobial activity, in particular, against antibiotic-resistant gram-negative bacteria. Methods. Minimum inhibitory and minimum bactericidal concentrations of the peptides (MIC and MBC) were determined using the broth microdilution assay followed by subculturing on agar plates. Effects of the AMPs on bacterial cytoplasmic membrane permeability for a chromogenic marker were explored using a genetically modified strain, Escherichia coli ML35p. The effect of bactenecins on bacterial metabolic activity was studied using a resazurin marker. Results. All the studied peptides showed a high in vitro antimicrobial activity against Escherichia coli ML35p and antibiotic-resistant strains, Escherichia coli ESBL and Acinetobacter baumannii, but differed in features of their action on bacterial cells. The used combination of techniques allowed the real-time monitoring of effects of bactenecin at different concentrations (including their MIC and MBC) on the cell membrane barrier function and metabolic activity of bacteria. The differences in effects of these three structurally different bactenecins on the studied microorganisms implied that these peptides at bactericidal concentrations differed in their capability for disintegrating bacterial cell membranes and rate of inhibiting bacterial metabolism. Conclusion. The obtained information will supplement the existing basic concepts on mechanisms involved in effects of proline-rich peptides of the innate immunity. This information will also stimulate biotechnological research aimed at development of new antibiotics for treatment of infectious diseases, such as severe in-hospital infections, caused by antibiotic-resistant strains.

Formulation and Evaluation of Mefloquine Hydrochloride Nanoparticles

2014 ◽  
Vol 7 (1) ◽  
pp. 2377-2386
Author(s):  
Dilip Kumar Gupta ◽  
B K Razdan ◽  
Meenakshi Bajpai
Keyword(s):  
Particle Size ◽  
Sustained Release ◽  
In Vitro Release ◽  
Entrapment Efficiency ◽  
Taste Masking ◽  
Diffusion Method ◽  
Drug Entrapment Efficiency ◽  
Resistant Strains ◽  
Vitro Release

The present study deals with the formulation and evaluation of mefloquine hydrochloride nanoparticles. Mefloquine is a blood schizonticidal quinoline compound, which is indicated for the treatment of mild-to-moderate acute malarial infections caused by mefloquine-susceptible multi-resistant strains of P. falciparum and P. vivax. The purpose of the present work is to minimize the dosing frequency, taste masking toxicity and to improve the therapeutic efficacy by formulating mefloquine HCl nanoparticles. Mefloquine nanoparticles were formulated by emulsion diffusion method using polymer poly(ε-caprolactone) with six different formulations. Nanoparticles were characterized by determining its particle size, polydispersity index, drug entrapment efficiency, drug content, particle morphological character and drug release. The particle size ranged between 100 nm to 240 nm. Drug entrapment efficacy was >95%. The in-vitro release of nanoparticles were carried out which exhibited a sustained release of mefloquine HCl from nanoparticles up to 24 hrs. The results showed that nanoparticles can be a promising drug delivery system for sustained release of mefloquine HCl.

scholarly journals Prevalence and Impact of Biofilms on Bloodstream and Urinary Tract Infections: A Systematic Review and Meta-Analysis

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 825
Author(s):  
Henrique Pinto ◽  
Manuel Simões ◽  
Anabela Borges
Keyword(s):  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Meta Analysis ◽  
Candida Spp ◽  
Treatment Interventions ◽  
Statistical Confidence ◽  
Resistant Strains ◽  
Meta Analyses ◽  
Tract Infections

This study sought to assess the prevalence and impact of biofilms on two commonly biofilm-related infections, bloodstream and urinary tract infections (BSI and UTI). Separated systematic reviews and meta-analyses of observational studies were carried out in PubMed and Web of Sciences databases from January 2005 to May 2020, following PRISMA protocols. Studies were selected according to specific and defined inclusion/exclusion criteria. The obtained outcomes were grouped into biofilm production (BFP) prevalence, BFP in resistant vs. susceptible strains, persistent vs. non-persistent BSI, survivor vs. non-survivor patients with BSI, and catheter-associated UTI (CAUTI) vs. non-CAUTI. Single-arm and two-arm analyses were conducted for data analysis. In vitro BFP in BSI was highly related to resistant strains (odds ratio-OR: 2.68; 95% confidence intervals-CI: 1.60–4.47; p < 0.01), especially for methicillin-resistant Staphylococci. BFP was also highly linked to BSI persistence (OR: 2.65; 95% CI: 1.28–5.48; p < 0.01) and even to mortality (OR: 2.05; 95% CI: 1.53–2.74; p < 0.01). Candida spp. was the microorganism group where the highest associations were observed. Biofilms seem to impact Candida BSI independently from clinical differences, including treatment interventions. Regarding UTI, multi-drug resistant and extended-spectrum β-lactamase-producing strains of Escherichia coli, were linked to a great BFP prevalence (OR: 2.92; 95% CI: 1.30–6.54; p < 0.01 and OR: 2.80; 95% CI: 1.33–5.86; p < 0.01). More in vitro BFP was shown in CAUTI compared to non-CAUTI, but with less statistical confidence (OR: 2.61; 95% CI: 0.67–10.17; p < 0.17). This study highlights that biofilms must be recognized as a BSI and UTI resistance factor as well as a BSI virulence factor.

Sign in / Sign up

Export Citation Format

Share Document