Biological activity of Pyraclostrobin against Coniella granati causing pomegranate crown rot

Plant Disease ◽  
2021 ◽  
Author(s):  
Xue Yang ◽  
Chun-Yan Gu ◽  
Yang Bai ◽  
Jia-Zhi Sun ◽  
Hao-Yu Zang ◽  
...  
Keyword(s):  
Biological Activity ◽  
Mycelial Growth ◽  
Field Trials ◽  
Crown Rot ◽  
Germination Inhibition ◽  
Control Efficacy ◽  
Intracellular Organelle ◽  
Transmission Electron ◽  
Excellent Control ◽  
Conidium Germination

Pomegranate crown rot caused by Coniellagranati is one of the most severe diseases of pomegranate. To date, no fungicides have been registered for controlling this disease in China. Pyraclostrobin, belonging to strobilurin fungicides, has a broad spectrum of activity against many phytopathogens. In this study, based on the mycelial growth and conidial germination inhibition methods, we investigated the biological activity of pyraclostrobin against C. granati at the presence of 50 μg/mL SHAM using 80 isolates collected from different orchards in China during 2012-2018. The EC50 (50% effective concentration) values ranged from 0.040-0.613 μg/mL for mycelial growth and 0.013-0.110 μg/mL for conidium germination, respectively. Treated with pyraclostrobin, the hyphae morphology changed and conidial production of C. granati decreased significantly. The result of transmission electron microscope showed that treatment of pyraclostrobin could make the cell wall thinner, and lead to ruptured cell membrane and formation of intracellular organelle autophagosomes. The pyraclostrobin showed good protective and curative activities against C. granati on detached pomegranate fruits. In field trials, pyraclostrobin showed excellent control efficacy against this disease in which the treatment of 25% pyraclostrobin EC 1000× provided 92.25% and 92.58% control efficacy in 2019 and 2020, respectively, significantly higher than that of other treatments. Therefore, pyraclostrobin could be a candidate fungicide for the control of pomegranate crown rot.

scholarly journals Baseline Sensitivity of Botrytis cinerea to the Succinate Dehydrogenase Inhibitor Isopyrazam and Efficacy of this Fungicide

Plant Disease ◽  
2016 ◽  
Vol 100 (7) ◽  
pp. 1314-1320 ◽  
Author(s):  
Yingying Song ◽  
Zhengqun Zhang ◽  
Lele Chen ◽  
Leiming He ◽  
Hongbao Lu ◽  
...  
Keyword(s):  
Succinate Dehydrogenase ◽  
Botrytis Cinerea ◽  
Spore Germination ◽  
Mycelial Growth ◽  
Field Trials ◽  
Baseline Sensitivity ◽  
Control Efficacy ◽  
Frequency Distributions ◽  
Geographical Regions ◽  
Succinate Dehydrogenase Inhibitor

Isopyrazam is a new broad-spectrum, foliar-absorbed and -translocated succinate dehydrogenase inhibitor fungicide. In this study, 159 Botrytis cinerea isolates collected from different geographical regions of Shandong Province of China were characterized for baseline sensitivity to isopyrazam. Furthermore, the protective and curative activity of isopyrazam on strawberry fruit and the control efficacy in the field were also determined. In contrast to its mycelial growth, the spore germination of B. cinerea was inhibited completely by lower concentrations of isopyrazam, about 1 μg ml−1 on yeast-peptone-acetate medium. Frequency distributions of isopyrazam 50% effective concentration (EC50) values were unimodal curves, with mean EC50 values of 0.07 ± 0.04 (standard deviation) and 0.68 ± 0.36 μg ml−1 for the inhibition of spore germination and mycelial growth, respectively. In addition, there was no positive multiple resistance between isopyrazam and other classes of botryticides such as diethofencarb, iprodione, pyrimethanil, or SYP-Z048. In field trials conducted during 2014 and 2015, isopyrazam used at a concentration of active ingredient at 150 and 200 g ha−1 provided a control efficacy ranging from 76.7 to 87.8% on leaves and from 81.5 to 90.7% on fruit. These results suggest that isopyrazam has the potential to play an important role in the management of gray mold.

scholarly journals Pharmacological Characteristics and Control Efficacy of a Novel SDHI Fungicide Pydiflumetofen Against Sclerotinia sclerotiorum

Plant Disease ◽  
2019 ◽  
Vol 103 (1) ◽  
pp. 77-82 ◽  
Author(s):  
Yabing Duan ◽  
Qian Xiu ◽  
Haoran Li ◽  
Tao Li ◽  
Jianxin Wang ◽  
...  
Keyword(s):  
Oilseed Rape ◽  
Sclerotinia Sclerotiorum ◽  
Field Trials ◽  
Cell Membrane Permeability ◽  
Sclerotinia Stem Rot ◽  
Baseline Sensitivity ◽  
Control Efficacy ◽  
Pharmacological Mechanism ◽  
Excellent Control ◽  
And Control

Pydiflumetofen is a novel succinate dehydrogenase inhibitor fungicide. In the current research, we determined the sensitivity of 166 Sclerotinia sclerotiorum strains to pydiflumetofen using mycelial growth inhibition method. The results suggest that pydiflumetofen exhibited a strong inhibitory activity against S. sclerotiorum and the EC50 values ranged from 0.0058 to 0.0953 μg ml−1, with a mean EC50 value of 0.0250 μg ml−1. However, the baseline sensitivity was not normally distributed because of a high variation factor. After treatment with pydiflumetofen, cell membrane permeability increases, but exopolysaccharide and oxalic acid production decreases, which contributes to reduced virulence of S. sclerotiorum and leads to failure of disease infection. In addition, protective and curative activity was performed on detached oilseed rape leaves by artificial inoculation. Pydiflumetofen exhibited excellent protective and curative effects against S. sclerotiorum on oilseed rape, and the protective effect was better than the curative effect. Further, field trials were conducted to evaluate the potential of pydiflumetofen in controlling Sclerotinia stem rot (SSR) caused by S. sclerotiorum on oilseed rape. Compared with the currently used fungicides, pydiflumetofen not only exhibited excellent control efficacy against SSR, but also dramatically reduced the dosage of fungicides in the field. Thus, this study provides important references for revealing pharmacological mechanism of pydiflumetofen against S. sclerotiorum and managing SSR on oilseed rape caused by benzimidazole- and dicarboximide-resistant populations.

scholarly journals In vitro biological activity of Hydroclathrus clathratus and its use as an extracellular bioreductant for silver nanoparticle formation

2020 ◽  
Vol 9 (1) ◽  
pp. 416-428 ◽  
Author(s):  
Raghad R. Alzahrani ◽  
Manal M. Alkhulaifi ◽  
Nouf M. Al-Enazi
Keyword(s):  
Biological Activity ◽  
Unsaturated Fatty Acids ◽  
Multidrug Resistant ◽  
Chemical Components ◽  
Resistant Bacteria ◽  
Transmission Electron ◽  
Hydroclathrus Clathratus ◽  
Adaptive Nature ◽  
First Time

AbstractThe adaptive nature of algae results in producing unique chemical components that are gaining attention due to their efficiency in many fields and abundance. In this study, we screened the phytochemicals from the brown alga Hydroclathrus clathratus and tested its ability to produce silver nanoparticles (AgNPs) extracellularly for the first time. Lastly, we investigated its biological activity against a variety of bacteria. The biosynthesized nanoparticles were characterized by UV-visible spectroscopy, Fourier-transform infrared spectroscopy, dynamic light scattering, transmission electron microscopy, and energy-dispersive spectroscopy. The biological efficacy of AgNPs was tested against eighteen different bacteria, including seven multidrug-resistant bacteria. Phytochemical screening of the alga revealed the presence of saturated and unsaturated fatty acids, sugars, carboxylic acid derivatives, triterpenoids, steroids, and other components. Formed AgNPs were stable and ranged in size between 7 and 83 nm and presented a variety of shapes. Acinetobacter baumannii, Staphylococcus aureus, Methicillin-resistant S. aureus (MRSA), and MDR A. baumannii were the most affected among the bacteria. The biofilm formation and development assay presented a noteworthy activity against MRSA, with an inhibition percentage of 99%. Acknowledging the future of nano-antibiotics encourages scientists to explore and enhance their potency, notably if they were obtained using green, rapid, and efficient methods.

scholarly journals Separate and combined Hanseniaspora uvarum and Metschnikowia pulcherrima metabolic volatiles are attractive to Drosophila suzukii in the laboratory and field

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
R. Jones ◽  
M. T. Fountain ◽  
C. S. Günther ◽  
P. E. Eady ◽  
M. R. Goddard
Keyword(s):  
Yeast Species ◽  
Field Trapping ◽  
Field Trials ◽  
Economic Losses ◽  
Drosophila Suzukii ◽  
Control Efficacy ◽  
Hanseniaspora Uvarum ◽  
Metschnikowia Pulcherrima ◽  
Rich Diversity ◽  
Relative Attractiveness

AbstractDrosophila suzukii flies cause economic losses to fruit crops globally. Previous work shows various Drosophila species are attracted to volatile metabolites produced by individual fruit associated yeast isolates, but fruits naturally harbour a rich diversity of yeast species. Here, we report the relative attractiveness of D. suzukii to yeasts presented individually or in combinations using laboratory preference tests and field trapping data. Laboratory trials revealed four of 12 single yeast isolates were attractive to D. suzukii, of which Metschnikowia pulcherrima and Hanseniaspora uvarum were also attractive in field trials. Four out of 10 yeast combinations involving Candida zemplinina, Pichia pijperi, M. pulcherrima and H. uvarum were attractive in the laboratory. Whilst a combination of M. pulcherrima + H. uvarum trapped the greatest number of D. suzukii in the field, the efficacy of the M. pulcherrima + H. uvarum combination to trap D. suzukii was not significantly greater than traps primed with volatiles from only H. uvarum. While volatiles from isolates of M. pulcherrima and H. uvarum show promise as baits for D. suzukii, further research is needed to ascertain how and why flies are attracted to certain baits to optimise control efficacy.

scholarly journals Synergistic Effect of Combined Application of a New Fungicide Fluopimomide with a Biocontrol Agent Bacillus methylotrophicus TA-1 for Management of Gray Mold in Tomato

Plant Disease ◽  
2019 ◽  
Vol 103 (8) ◽  
pp. 1991-1997 ◽  
Author(s):  
Xiaoxue Ji ◽  
Jingjing Li ◽  
Zhen Meng ◽  
Shouan Zhang ◽  
Bei Dong ◽  
...  
Keyword(s):  
Field Experiments ◽  
Biocontrol Agent ◽  
Severe Disease ◽  
Combined Treatment ◽  
Field Trials ◽  
Antimicrobial Activities ◽  
Gray Mold ◽  
Control Efficacy ◽  
Bacillus Methylotrophicus

Gray mold caused by Botrytis cinerea can be a severe disease of tomato infecting leaves and fruits of tomato plants. Chemical control is currently the most effective and reliable method; however, application of fungicides has many drawbacks. The combination of biological control agents with newly developed fungicides may be a practicable method to control B. cinerea. Fluopimomide is a newly developed fungicide with a novel mode of action. Bacillus methylotrophicus TA-1, isolated from rhizosphere soil of tomato, is a bacterial strain with a broad spectrum of antimicrobial activities. Little information is currently available about the effect of fluopimomide and its integrated effect on B. cinerea. Therefore, laboratory, pot, and field experiments were carried out to determine the effects of fluopimomide alone and in combination with B. methylotrophicus TA-1 against gray mold on tomato. The in vitro growth of B. methylotrophicus TA-1 was unaffected by 100 mg liter−1 fluopimomide. Inhibition of B. cinerea mycelial growth was significantly increased under combined treatment of fluopimomide and B. methylotrophicus TA-1. In greenhouse experiments, efficacy against gray mold was significantly greater by an integration of fluopimomide and B. methylotrophicus TA-1 than by either alone; control efficacy of fluopimomide at 50 and 100 g ha−1 in combination with B. methylotrophicus TA-1 at 108 colony-forming units (cfu) ml−1 reached 70.16 and 69.32%, respectively, compared with the untreated control. In both field trials during 2017 and 2018, control efficacy was significantly higher for the combination of fluopimomide at 50 and 100 g ha−1 in combination with B. methylotrophicus TA-1 than for either treatment alone. The results from this study indicated that integration of the new fungicide fluopimomide with the biocontrol agent B. methylotrophicus TA-1 synergistically increased control efficacy of the fungicide against gray mold of tomato.

scholarly journals Evaluating the Sensitivity and Efficacy of Fungicides with Different Modes of Action Against Botryosphaeria dothidea

Plant Disease ◽  
2018 ◽  
Vol 102 (9) ◽  
pp. 1785-1793 ◽  
Author(s):  
Yingying Song ◽  
Lili Li ◽  
Chao Li ◽  
Zengbin Lu ◽  
Xingyuan Men ◽  
...  
Keyword(s):  
Field Trials ◽  
Apple Fruit ◽  
Effective Concentration ◽  
Botryosphaeria Dothidea ◽  
Control Efficacy ◽  
Frequency Distributions ◽  
Considerable Potential ◽  
Ring Rot ◽  
Fungal Plant Pathogen ◽  
The Mean

Botryosphaeria dothidea, the causal agent of apple ring rot, is an important fungal plant pathogen that can cause serious reductions in crop yield, and fungicides still play a crucial role in management. In the present study, the sensitivity of B. dothidea to fludioxonil, fluazinam, and pyrisoxazole was assessed in 162 isolates. Moreover, the protective and curative activity of the three fungicides on detached apple fruit as well as the control efficacy in the field were determined. The results showed that the mean 50% effective concentration (EC50) values (± standard deviation) were 0.01 ± 0.008, 0.04 ± 0.03, and 0.02 ± 0.01 μg ml−1, with individual EC50 values of 0.002 to 0.05, 0.003 to 0.19, and 0.005 to 0.26 μg ml−1 for fludioxonil, fluazinam, and pyrisoxazole, respectively. In addition, the frequency distributions of EC50 values were both unimodal curves. However, significant correlations (P < 0.05) were found between fludioxonil and iprodione, between fluazinam and iprodione, as well as between pyrisoxazole and difenoconazole. In field trials conducted during 2016 and 2017, the control efficacy ranged from 75.91 to 87.41% when fludioxonil was applied at 100 to 150 mg active ingredient (a.i.) kg−1, 81.90 to 85.13% when fluazinam was applied at 400 mg a.i. kg−1, and 77.43 to 80.97% when pyrisoxazole was applied at 400 mg a.i. kg−1. The control efficacy of the fungicides in storage was higher than 60%, with the exception of fluazinam. These results demonstrated that fludioxonil, fluazinam, and pyrisoxazole have considerable potential to control apple ring rot.

Activity of A Novel Succinate Dehydrogenase Inhibitor Fungicide Pydiflumetofen against Fusarium fujikuroi causing Rice Bakanae Disease

Plant Disease ◽  
2021 ◽  
Author(s):  
Yang Bai ◽  
Chun-Yan Gu ◽  
Rui Pan ◽  
Muhammad Abid ◽  
Hao-Yu Zang ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Succinate Dehydrogenase ◽  
Field Trials ◽  
Cell Membrane Permeability ◽  
Cross Resistance ◽  
Fusarium Fujikuroi ◽  
Control Efficacy ◽  
Bakanae Disease ◽  
Geographical Regions ◽  
Succinate Dehydrogenase Inhibitor

New fungicides are tools to manage fungal diseases and overcome emerging resistance in fugnal pathogens. In this study, a total of 121 isolates of Fusarium fujikuroi, the causal agent of rice bakanae disease (RBD), were collected from various geographical regions of China, and their sensitivity to a novel succinate dehydrogenase inhibitor (SDHI)fungicide ‘pydiflumetofen’ was evaluated. The 50% effective concentration (EC50) value of pydiflumetofen for mycelial growth suppression ranged from 0.0101 to 0.1012 μg/ml and for conidial germination inhibition ranged from 0.0051to 0.1082 μg/ml. Pydiflumetofen treated hyphae showed contortion and increased branching, cell membrane permeability, and glycerol content significantly. The result of electron microscope transmission indicated that pydiflumetofen damaged the mycelial cell wall and the cell membrane, and almost broken up the cells, which increased the intracellular plasma leakage. There was no cross-resistance between pydiflumetofen and the widely used fungicides such as carbendazim, prochloraz, and phenamacril. Pydiflumetofen was found safe to seeds and rice seedlings of four rice cultivars, used up to 400 μg/ml. Seed treatment significantly decreased the rate of diseased plants in the greenhouse as well as in field trials in 2017 and 2018. Pydiflumetofen showed superb results against RBD, when used at 10 or 20 g a.i./100 kg of treated seeds, providing over 90% control efficacy (the highest control efficacy was up to 97%), which was significantly higher than that of 25% phenamacril (SC) at 10g or carbendazim at 100 g. Pydiflumetofen is highly effective against F. fujikuroi growth and sporulation as well as RBD in the field.

scholarly journals Characterization of Antagonistic Bacillus methylotrophicus Isolated From Rhizosphere and Its Biocontrol Effects on Maize Stalk Rot

2019 ◽  
Vol 109 (4) ◽  
pp. 571-581 ◽  
Author(s):  
Xingkai Cheng ◽  
Xiaoxue Ji ◽  
Yanzhen Ge ◽  
Jingjing Li ◽  
Wenzhe Qi ◽  
...  
Keyword(s):  
Biochemical Characterization ◽  
Disease Incidence ◽  
Field Trials ◽  
Control Measures ◽  
Disease Suppression ◽  
Effective Control ◽  
Stalk Rot ◽  
Bacillus Methylotrophicus ◽  
Transmission Electron ◽  
Potential Biocontrol Agent

Stalk rot is one of the most serious and widespread diseases in maize, and effective control measures are currently lacking. Therefore, this study aimed to develop a new biological agent to manage this disease. An antagonistic bacterial strain, TA-1, was isolated from rhizosphere soil and identified as Bacillus methylotrophicus based on morphological and biochemical characterization and 16S ribosomal RNA and gyrB gene sequence analyses. TA-1 exhibited a strong antifungal effect on the growth of Fusarium graminearum mycelium, with 86.3% inhibition at a concentration of 108 CFU per ml. Transmission electron microscopy showed that TA-1 could disrupt the cellular structure of the fungus, induce necrosis, and degrade the cell wall. Greenhouse and field trials were performed to evaluate the biocontrol efficacy of TA-1 on maize stalk rot, and the results of greenhouse experiment revealed that the bacterium significantly reduced disease incidence and disease index. Seeds treated with a 108 CFU ml−1 cell suspension had the highest disease suppression at 86.8%. Results of field trials show that seed bacterization with TA-1 could not only reduce maize stalk rot incidence but also increase maize height, stem diameter, and grain yield. The lipopeptide antibiotics were isolated from the culture supernatants of TA-1 and identified as surfactins and iturins. Consequently, B. methylotrophicus TA-1 is a potential biocontrol agent against maize stalk rot.

scholarly journals Sensitivity of Cercospora beticola Isolates to Azoxystrobin

2020 ◽  
Vol 69 (1-2) ◽  
pp. 1-4
Author(s):  
Milijanka Balandžić ◽  
Vera Stojšin ◽  
Mila Grahovac ◽  
Ferenc Bagi ◽  
Mladen Petreš ◽  
...  
Keyword(s):  
Biological Activity ◽  
High Risk ◽  
Sugar Beet ◽  
Mycelial Growth ◽  
Cercospora Beticola ◽  
Experimental Site ◽  
Sugar Beets ◽  
Qoi Fungicides ◽  
Moderately Resistant ◽  
Very High

SummarySugar beet leaf spot, caused by the air-borne fungus Cercospora beticola Sacc., leads to a decrease in sugar beet leaf mass and the consequent regrowth of leaves based on exploiting the sugar reserves stored in the plant’s roots, thus ultimately resulting in lower yields and sugar contents of sugar beets. Azoxystrobin belongs to the group of QoI fungicides, which inhibit mitochondrial respiration by blocking cytochrome c reductase. The QoI fungicides are characterized by a very high risk of resistance interfering with their biological activity. For the purpose of testing the azoxystrobin sensitivity of the Cercospora beticola population found at the site of Rimski Šančevi, a collection of 84 isolates was assembled and tested for sensitivity to azoxystrobin by measuring the mycelial growth on fungicide-amended media with the addition of SHAM. The results obtained indicate that none of the isolates tested exhibited complete sensitivity to azoxystrobin, 4% were found to have reduced sensitivity, 26% were moderately resistant and 70% were highly resistant. A higher proportion of resistant isolates recorded is associated with the loss of azoxystrobin biological efficacy at the experimental site.

scholarly journals Genetic Variance for Fusarium Crown Rot Tolerance in Durum Wheat

2020 ◽  
Author(s):  
Gururaj Kadkol ◽  
Jess Meza ◽  
Steven Simpfendorfer ◽  
Steve Harden ◽  
Brian Cullis
Keyword(s):  
Durum Wheat ◽  
Bread Wheat ◽  
Genetic Variance ◽  
Field Trials ◽  
Crown Rot ◽  
Tolerance Index ◽  
Fusarium Crown Rot ◽  
N Yield ◽  
Good Repeatability ◽  
Tolerance Indices

AbstractTolerance to the cereal disease Fusarium crown rot (FCR) was investigated in a set of 34 durum wheat genotypes, with Suntop, (bread wheat) and EGA Bellaroi (durum) as tolerant and intolerant checks, in a series of replicated field trials over four years with inoculated (FCR-i) and non-inoculated (FCR-n) plots of the genotypes. The genotypes included conventional durum lines and lines derived from crossing durum with 2-49, a bread wheat line with the highest level of partial resistance to FCR. A split plot trial design was chosen to optimize the efficiency for the prediction of FCR tolerance for each genotype. A multi-environment trial (MET) analysis was undertaken which indicated that there was good repeatability of FCR tolerance across years. Based on an FCR tolerance index, Suntop was the most tolerant genotype and EGA Bellaroi was very intolerant, but many durum wheats had FCR tolerance indices which were comparable to Suntop. These included some conventional durum lines, V101030, TD1702, V11TD013*3X-63 and DBA Bindaroi, as well as genotypes from crosses with 2-49 (V114916 and V114942). The correlation between FCR tolerance and FCR-n yield predictions was moderately negative indicating it could be somewhat difficult to develop high yielding FCR-tolerant genotypes. However, FCR tolerance showed a positive correlation with FCR-i yield predictions in seasons of high disease expression indicating it could be possible to screen for FCR tolerance using only FCR-i treatments. These results are the first demonstration of genetic diversity in durum germplasm for FCR tolerance and they provide a basis for breeding for this trait.

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