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

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.

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Symbiotic NCR Peptide Fragments Affect the Viability, Morphology and Biofilm Formation of Candida Species

International Journal of Molecular Sciences ◽

10.3390/ijms22073666 ◽

2021 ◽

Vol 22 (7) ◽

pp. 3666

Author(s):

Bettina Szerencsés ◽

Attila Gácser ◽

Gabriella Endre ◽

Ildikó Domonkos ◽

Hilda Tiricz ◽

...

Keyword(s):

Candida Species ◽

Biofilm Formation ◽

Therapeutic Potential ◽

Fungal Infections ◽

Combined Treatment ◽

Antimicrobial Activities ◽

Dilution Method ◽

Model Legume ◽

Anticandidal Activity

The increasing rate of fungal infections causes global problems not only in human healthcare but agriculture as well. To combat fungal pathogens limited numbers of antifungal agents are available therefore alternative drugs are needed. Antimicrobial peptides are potent candidates because of their broad activity spectrum and their diverse mode of actions. The model legume Medicago truncatula produces >700 nodule specific cysteine-rich (NCR) peptides in symbiosis and many of them have in vitro antimicrobial activities without considerable toxicity on human cells. In this work we demonstrate the anticandidal activity of the NCR335 and NCR169 peptide derivatives against five Candida species by using the micro-dilution method, measuring inhibition of biofilm formation with the XTT (2,3-Bis-(2-Methoxy-4-Nitro-5-Sulfophenyl)-2H-Tetrazolium-5-Carboxanilide) assay, and assessing the morphological change of dimorphic Candida species by microscopy. We show that both the N- and C-terminal regions of NCR335 possess anticandidal activity as well as the C-terminal sequence of NCR169. The active peptides inhibit biofilm formation and the yeast-hypha transformation. Combined treatment of C. auris with peptides and fluconazole revealed synergistic interactions and reduced 2-8-fold the minimal inhibitory concentrations. Our results demonstrate that shortening NCR peptides can even enhance and broaden their anticandidal activity and therapeutic potential.

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Impact of the biofungicide tetramycin on the development of Fusarium head blight, grain yield and deoxynivalenol accumulation in wheat

World Mycotoxin Journal ◽

10.3920/wmj2019.2494 ◽

2020 ◽

Vol 13 (2) ◽

pp. 235-246

Author(s):

W.Q. Shi ◽

L.B. Xiang ◽

D.Z. Yu ◽

S.J. Gong ◽

L.J. Yang

Keyword(s):

Fusarium Head Blight ◽

Fusarium Graminearum ◽

Spore Germination ◽

Field Experiments ◽

Synergistic Effects ◽

Field Trials ◽

Head Blight ◽

Mycelium Growth ◽

Key Aspects

Fusarium graminearum causes Fusarium head blight (FHB), a devastating disease that leads to extensive yield and quality loss in wheat and barley production. Integrated pest management (IPM) is required to control this disease and biofungicides, such as tetramycin, could be a novel addition to IPM strategies. The current study investigated in vitro tetramycin toxicity in Fusarium graminearum and evaluated its effectiveness for the control of Fusarium head blight FHB. Tetramycin was shown to affect three key aspects of Fusarium pathogenicity: spore germination, mycelium growth and deoxynivalenol (DON) production. The in vitro results indicated that tetramycin had strong inhibitory activity on the mycelial growth and spore germination. Field trials indicated that tetramycin treatment resulted in a significant reduction in both the FHB disease index and the level of DON accumulation. The reduced DON content in harvested grain was correlated with the amount of Tri5 mRNA determined by qRT-PCR. Synergistic effects between tetramycin and metconazole, in both the in vitro and field experiments were found. Tetramycin could provide an alternative option to control FHB.

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Antimicrobial Effects of Selected, Cultivated Red Seaweeds and Their Components in Combination with Tetracycline, against Poultry Pathogen Salmonella Enteritidis

Journal of Marine Science and Engineering ◽

10.3390/jmse8070511 ◽

2020 ◽

Vol 8 (7) ◽

pp. 511

Author(s):

Garima Kulshreshtha ◽

Alan Critchley ◽

Bruce Rathgeber ◽

Glenn Stratton ◽

Arjun H. Banskota ◽

...

Keyword(s):

Salmonella Enteritidis ◽

Combined Treatment ◽

Water Extract ◽

Antimicrobial Activities ◽

Human Consumption ◽

Drug Resistant ◽

Red Seaweeds ◽

Industry Standard ◽

Prophylactic Use

Poultry and its products are an economical source of high-quality protein for human consumption. In animal agriculture, antibiotics are used as therapeutic agents to treat disease in livestock, or as prophylactics to prevent disease and in so doing enhance production. However, the extensive use of antibiotics in livestock husbandry has come at the cost of increasingly drug-resistant bacterial pathogens. This highlights an urgent need to find effective alternatives to be used to treat infections, particularly in poultry and especially caused by drug-resistant Salmonella strains. In this study, we describe the combined effect of extracts of the red seaweeds Chondrus crispus (CC) and Sarcodiotheca gaudichaudii (SG) and compounds isolated from these in combinations with industry standard antibiotics (i.e., tetracycline and streptomycin) against Salmonella Enteritidis. Streptomycin exhibited the higher antimicrobial activity against S. Enteritidis, as compared to tetracycline with a MIC25 and MIC50 of 1.00 and 1.63 μg/mL, respectively. The addition of a water extract of CC at a concentration of 200 µg/mL in addition to tetracycline significantly enhanced the antibacterial activity (log CFU/mL 4.7 and 4.5 at MIC25 and MIC50, respectively). SG water extract, at 400 and 800 µg/mL (p = 0.05, n = 9), also in combination with tetracycline, showed complete inhibition of bacterial growth. Combinations of floridoside (a purified red seaweed component) and tetracycline (MIC25 and MIC50) in vitro revealed that only the lower concentration (i.e., 15 μg/mL) of floridoside potentiated the activity of tetracycline. Sub-lethal concentrations of tetracycline (MIC50 and MIC25), in combination with floridoside, exhibited antimicrobial activities that were comparable to full-strength tetracycline (23 μg/mL). Furthermore, the relative transcript levels of efflux-related genes of S. Enteritidis, namely marA, arcB and ramA, were significantly repressed by the combined treatment of floridoside and tetracycline, as compared to control MIC treatments (MIC25 and MIC50). Taken together, these findings demonstrated that the red seaweeds CC and SG and their selected, purified components can be used to increase the lifetime of existing, patented antibiotics and can also help to reduce costly (economic and environmental) therapeutic and prophylactic use of antibiotics in poultry. To our knowledge, this is the first report of antibiotic potentiation of existing industry standard antibiotics using red seaweeds and their selected extracts against S. Enteritidis.

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Verticillium Wilt in Oilseed Rape—the Microbiome is Crucial for Disease Outbreaks as Well as for Efficient Suppression

Plants ◽

10.3390/plants9070866 ◽

2020 ◽

Vol 9 (7) ◽

pp. 866 ◽

Cited By ~ 1

Author(s):

Daria Rybakova ◽

Mariann Wikström ◽

Fia Birch-Jensen ◽

Joeke Postma ◽

Ralf Udo Ehlers ◽

...

Keyword(s):

Verticillium Wilt ◽

Severe Disease ◽

Disease Outbreaks ◽

Field Trials ◽

Growth Conditions ◽

Assessment Method ◽

Serratia Plymuthica ◽

Hierarchical Selection

Microbiome management is a promising way to suppress verticillium wilt, a severe disease in Brassica caused by Verticillium longisporum. In order to improve current biocontrol strategies, we compared bacterial Verticillium antagonists in different assays using a hierarchical selection and evaluation scheme, and we integrated outcomes of our previous studies. The result was strongly dependent on the assessment method chosen (in vitro, in vivo, in situ), on the growth conditions of the plants and their genotype. The most promising biocontrol candidate identified was a Brassica endophyte Serratia plymuthica F20. Positive results were confirmed in field trials and by microscopically visualizing the three-way interaction. Applying antagonists in seed treatment contributes to an exceptionally low ecological footprint, supporting efficient economic and ecological solutions to controlling verticillium wilt. Indigenous microbiome, especially soil and seed microbiome, has been identified as key to understanding disease outbreaks and suppression. We suggest that verticillium wilt is a microbiome-driven disease caused by a reduction in microbial diversity within seeds and in the soil surrounding them. We strongly recommend integrating microbiome data in the development of new biocontrol and breeding strategies and combining both strategies with the aim of designing healthy microbiomes, thus making plants more resilient toward soil-borne pathogens.

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Performance and Resistance to Phytophthora Crown and Root Rot in Squash Lines

HortTechnology ◽

10.21273/horttech04636-20 ◽

2020 ◽

Vol 30 (5) ◽

pp. 608-618 ◽

Cited By ~ 1

Author(s):

Kyle E. LaPlant ◽

Gregory Vogel ◽

Ella Reeves ◽

Christine D. Smart ◽

Michael Mazourek

Keyword(s):

Root Rot ◽

Cucurbita Pepo ◽

Field Experiments ◽

Phytophthora Capsici ◽

Severe Disease ◽

Field Trials ◽

Disease Symptoms ◽

Resistant Lines ◽

Oomycete Pathogen ◽

Crown And Root Rot

Phytophthora crown and root rot, caused by the oomycete pathogen Phytophthora capsici, is a devastating disease of squash and pumpkin (Cucurbita pepo). No currently available cultivars provide complete resistance to this disease. Three newly developed squash lines and four hybrids were evaluated in greenhouse and field experiments for their resistance to phytophthora crown and root rot as well as for their horticultural performance. The three newly developed lines ranked among the most resistant entries included in 2 years of field trials. In addition, in a separate greenhouse experiment, one of the lines was shown to display the least severe disease symptoms among a group of accessions previously reported to possess partial resistance to phytophthora crown and root. Furthermore, the resistance was observed to be robust to several isolates of P. capsici. However, the phytophthora-resistant lines had reduced yield relative to standard squash cultivars. These lines are useful for continued breeding efforts toward a phytophthora crown and root rot-resistant cultivar.

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Antifungal volatiles from macrobasidiomycetes inhibits Fusarium oxysporum f.sp. lycopersici

Madras Agricultural Journal ◽

10.29321/maj.10.000476 ◽

2021 ◽

Vol 108 (March) ◽

pp. 1-4

Author(s):

Praveen Thangaraj ◽

◽

Krishnamoorthy Akkana Subbiah ◽

Sivakumar Uthandi ◽

Amirtham D ◽

...

Keyword(s):

Fungal Pathogen ◽

Biocontrol Agent ◽

Antimicrobial Activities ◽

Biological Properties ◽

Coprinus Cinereus ◽

Vegetable Crops ◽

Headspace Volatiles ◽

Antifungal Volatiles ◽

Area Percentage

Several macrobasidiomycete fungi have potential biological properties naturally to combat fungal diseases. F.oxysporum f.sp. lycopersici is a soilborne ascomycetous fungus, which causes disease in several vegetable crops. The present study aimed to explore the antifungal activity of VOCs produced by several macrobasidiomycete fungi against F. oxysporum f.sp. lycopersici. The VOCs emitted by macrobasidiomycete fungi were demonstrated by the inverted sealed plate assay against the target pathogen. Among the mushroom isolate tested in vitro, the VOCs exhibited from Coprinus cinereus inhibited 70 % mycelial growth of F. oxysporum f.sp. lycopersici, followed by Ganoderma lucidum (60.28 %) and Lentinus edodes (35.28 %). In addition to inhibition of the pathogen, the headspace volatiles emitted by the effective isolate were trapped by Tenax column and subjected to GC-MS analysis. A total of 15 and 25 VOCs were identified from C. cinereus and G. lucidum, respectively. Among them, Alfa copaene showed a peak area percentage of 7.82 (14.99 RT) in Coprinus cinereus. followed by 2 undecanone. Similarly, trichloromethane and 1- pentanol produced from G. lucidum, showed high relative abundance of 71.5 per cent at 9.84 RT and 70.3 per cent at 2.69 RT, respectively. The VOCs produced by macrobasidiomycete fungi could possess antimicrobial activities against the fungal pathogen. These volatile compounds may be explored as a novel biocontrol agent against soil borne pathogens of vegetable crop.

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Fungicidal preparations from Inula viscosa

Plant Protection Science ◽

10.17221/10575-pps ◽

2017 ◽

Vol 38 (SI 2 - 6th Conf EFPP 2002) ◽

pp. 629-630 ◽

Cited By ~ 12

Author(s):

Y. Cohen ◽

A. Baider ◽

B. Ben-Daniel ◽

Y. Ben-Daniel

Keyword(s):

Field Experiments ◽

Fungicidal Activity ◽

Plasmopara Viticola ◽

Gray Mold ◽

Effective Control ◽

Grape Vine ◽

Perennial Plant ◽

Agricultural Use

Inula viscosa is a perennial plant native to the Mediterranean Basin. Extracts made from the shoots of this plant exhibited a strong fungicidal activity in vitro and in vivo. TLC analyses revealed at least 7 fungicidal compounds. Most are lipophilic. When such extracts were sprayed on the leaf surface of crop plants they effectively controlled downy mildew in grape, cucumber and tobacco; late blight in potato and tomato; gray mold in cucumber and tomato; and, powdery mildew in cucurbits and cereals. Field experiments conducted with grape vine and potato resulted in effective control of Plasmopara viticola and Phytophthora infestans, respectively. The data suggest that Inula viscosa is a useful source of herbal fungicidal preparations for agricultural use.

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Effect of Fungicide Application on the Management of Avocado Branch Canker (Formerly Dothiorella Canker) in California

Plant Disease ◽

10.1094/pdis-06-12-0518-re ◽

2013 ◽

Vol 97 (7) ◽

pp. 897-902 ◽

Cited By ~ 6

Author(s):

M. Twizeyimana ◽

V. McDonald ◽

J. S. Mayorquin ◽

D. H. Wang ◽

F. Na ◽

...

Keyword(s):

Field Experiment ◽

Mycelial Growth ◽

Fungal Pathogens ◽

Field Experiments ◽

Field Trials ◽

Persea Americana ◽

Lesion Length ◽

Length Data ◽

Branch Canker

Members of the Botryosphaeriaceae family have been associated with branch cankers of avocado trees (Persea americana) in California. Canker infections are initiated by spores entering the host plant through fresh wounds such as pruning wounds. With high-density planting becoming more common in the California avocado industry, more intensive pruning may increase the occurrence of branch canker. The objective of this study was to evaluate the preventive ability of some commercial fungicides belonging to different chemical families against fungal pathogens associated with avocado branch canker. Initially, 12 fungicides were tested in vitro for their effect on the inhibition of mycelial growth of three isolates of Dothiorella iberica and isolates (five per species) of Neofusicoccum australe, N. luteum, N. parvum, and Phomopsis sp. Subsequently, azoxystrobin, fludioxonil, metconazole, and pyraclostrobin, selected because of their low effective concentrations that reduce 50% of mycelial growth (EC50 values), and myclobutanil, selected for its high EC50 value, were tested in two field experiments. Azoxystrobin and fludioxonil were used in a premix with propiconazole and cyprodinil, respectively, in field trials. Significant differences (P < 0.05) were observed among fungicides in field trials. Azoxystrobin + propiconazole had the highest percent inhibition at 52 and 62% (internal lesion length) in trial 1 and trial 2, respectively, although this level of inhibition was not significantly different from that of metconazole. A significant correlation (r = 0.51, P < 0.05) was observed between internal lesion length data in the field experiment and EC50 data from in vitro fungicide screening. Application of azoxystrobin + propiconazole and metconazole can play a key role in protecting Californian avocado against fungi causing avocado branch canker.

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Phage PPPL-1, a New Biological Agent to Control Bacterial Canker Caused by Pseudomonas syringae pv. actinidiae in Kiwifruit

Antibiotics ◽

10.3390/antibiotics10050554 ◽

2021 ◽

Vol 10 (5) ◽

pp. 554

Author(s):

Yu-Rim Song ◽

Nguyen Trung Vu ◽

Jungkum Park ◽

In Sun Hwang ◽

Hyeon-Ju Jeong ◽

...

Keyword(s):

Pseudomonas Syringae ◽

Biocontrol Agent ◽

Control Agent ◽

Bacterial Canker ◽

Control Efficacy ◽

Antibiotic Resistant ◽

Canker Disease ◽

Recent Emergence ◽

Phage Cocktail

Pseudomonas syringae pv. actinidiae (Psa) is a Gram-negative bacterium that causes bacterial canker disease in kiwifruit. Copper or antibiotics have been used in orchards to control this disease, but the recent emergence of antibiotic-resistant Psa has called for the development of a new control agent. We previously reported that the bacteriophage (or phage) PPPL-1 showed antibacterial activity for both biovar 2 and 3 of Psa. To investigate the possibility of PPPL-1 to control bacterial canker in kiwifruit, we further tested the efficacy of PPPL-1 and its phage cocktail with two other phages on suppressing disease development under greenhouse conditions using 6 weeks old kiwifruit plants. Our results showed that the disease control efficacy of PPPL-1 treatment was statistically similar to those of phage cocktail treatment or AgrimycinTM, which contains streptomycin and oxytetracycline antibiotics as active ingredients. Moreover, PPPL-1 could successfully kill streptomycin-resistant Psa isolates, of which the treatment of BuramycinTM carrying only streptomycin as an active ingredient had no effect in vitro. The phage PPPL-1 was further characterized, and stability assays showed that the phage was stable in the field soil and at low temperature of 0 ± 2 °C. In addition, the phage could be scaled up quickly up to 1010 pfu/mL at 12 h later from initial multiplicity of infection of 0.000005. Our results indicate that PPPL-1 phage is a useful candidate as a biocontrol agent and could be a tool to control the bacterial canker in kiwifruit by Psa infection in the field conditions.

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Impact of SDH Mutations in Alternaria solani on Recently Developed SDHI Fungicides Adepidyn and Solatenol

Plant Disease ◽

10.1094/pdis-12-20-2718-re ◽

2021 ◽

Author(s):

Sarah Rodriguez ◽

Rhodesia Celoy ◽

Ipsita Mallik ◽

Julie Sherman Pasche ◽

Neil C Gudmestad

Keyword(s):

Early Blight ◽

Field Experiments ◽

Alternaria Solani ◽

Potato Production ◽

Field Trials ◽

Intrinsic Activity ◽

In Vitro Assays ◽

Commercial Application ◽

Quinone Outside Inhibitor

Early blight, caused by Alternaria solani, is observed annually in all midwestern potato production areas. The use of foliar fungicides remains a primary management strategy. However, A. solani has developed reduced-sensitivity or resistance to many single-site fungicides such as quinone outside inhibitor (QoI, FRAC group 11), succinate dehydrogenase inhibitor (SDHI, FRAC group 7), demethylation inhibitors (DMI, FRAC group 3), and anilinopyrimidine (AP, FRAC group 9) fungicides. Boscalid, fluopyram, solatenol, and adepidyn are EPA-registered SDHI fungicides used commercially on a variety of crops, including potato. Five SDH mutations have been characterized previously in A. solani that affect the efficacy of boscalid while only one of these mutations has been demonstrated to negatively affect fluopyram efficacy. Conidial germination assays were used to determine if a shift in sensitivity has occurred in these SDHI fungicides. Alternaria solani isolates collected prior to the commercial application of SDHI fungicides (baseline) and were compared to recently collected isolates (non-baseline). Greenhouse evaluations were conducted also to evaluate the efficacy of boscalid, fluopyram, solatenol, and adepidyn on A. solani isolates possessing individual SDH mutations. Additionally, field trials were conducted to determine the effects application of these SDHI fungicides on the frequency of SDH mutations. Fluopyram, solatenol, and adepidyn had high intrinsic activity against A. solani when compared to boscalid, based on in vitro assays. The application of adepidyn and solatenol resulted in greater early blight control than the application of boscalid and fluopyram in greenhouse experiments. Molecular characterization of A. solani isolates collected from the field trials determined that the frequency of the H134R-mutation can increase in response to more recently developed SDHI fungicides. In contrast, the H278R/Y- and H133R-mutations decreased to the point of being nearly absent in these field experiments.

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