scholarly journals In vitro effect of salinity and pH on Fusarium sp., the causal agent of sweet-potato root rot

2021 ◽  
Vol 3 (2) ◽  
pp. 42-47
Author(s):  
Lavinia Diana Nicoleta Barbu ◽  
◽  
Oana Alina Boiu Secoia
Keyword(s):  
Sweet Potato ◽  
Root Rot ◽  
Reference Strain ◽  
Saline Water ◽  
Fungal Growth ◽  
Prolonged Incubation ◽  
Wide Range ◽  
Fusarium Sp ◽  
Vitro Effect

Fusarium root rot in a common pathogen of sweet potato, with a wide range of host plants. In the current study six new isolates of Fusarium sp., collected from infected sweet potato plants, along with a reference strain of Fusarium oxysporum, had their growth behavior studied in various pH and saline conditions. In vitro studies showed that salinity higher than 6% NaCl in the PDA substrate significantly reduces the fungal growth. At 12% NaCl, four of seven strains revealed complete mycelia inhibition. However, for the other two isolates, and for the reference strain, 12% salinity only reduced the growth with 77.4%. Regarding the fungal growth at different pH values, it was noticed that tested fusaria were not perturbed at up to 8.5 alkalinity. However, at a pH of 4.5, the growth rate was reduced, although the growth differences were diminished during prolonged incubation time. Considering the in vitro results, saline water should be tested as preventive immersion treatment on the sweet potato sprouts, before their planting, in order to reduce the incidence of Fusarium infection.

An evaluation of potential seed treatments to control Fusarium solani f.sp. phaseoli, the cause of foot and root rot of Phaseolus vulgaris

1977 ◽  
Vol 89 (1) ◽  
pp. 235-238 ◽  
Author(s):  
P. E. Russell ◽  
A. E. A. Mussa
Keyword(s):  
Phaseolus Vulgaris ◽  
Fusarium Solani ◽  
Root Rot ◽  
Similar Pattern ◽  
Fungal Growth ◽  
Systemic Fungicide ◽  
Product Concentration ◽  
Low Concentrations ◽  
High Concentrations

SummaryTwo systemic fungicides, benomyl and thiabendazole, were more active than the non-systemic fungicide Drazoxolon in inhibiting fungal growth in vitro. A similar pattern was obtained in glasshouse trials with benomyl and thiabendazole giving adequate protection at low concentrations while Drazoxolon was ineffective unless applied at 50% the commercial product concentration. A field trial using thiabendazole, Drazoxolon and a mixture of benomyl and thiram confirmed the glasshouse results.Some phytotoxicity was noticed with high concentrations of both benomyl and thiabendazole, but satisfactory disease control was achieved using fungicide concentrations which did not induce phytotoxicity.

scholarly journals Effects of Temperature and pH on Fusarium oxysporum and Soybean Seedling Disease

Plant Disease ◽  
2019 ◽  
Vol 103 (12) ◽  
pp. 3234-3243
Author(s):  
David R. Cruz ◽  
Leonor F. S. Leandro ◽  
Gary P. Munkvold
Keyword(s):  
Fusarium Oxysporum ◽  
Root Rot ◽  
Radial Growth ◽  
Culture Media ◽  
Fungal Growth ◽  
Artificial Culture ◽  
Vitro Assay ◽  
Seedling Disease ◽  
Soybean Seedlings

Fusarium oxysporum (Fo) is an important pathogen that reduces soybean yield by causing seedling disease and root rot. This study assessed the effects of pH and temperature on Fo fungal growth and seedling disease. In an in vitro assay, 14 Fo isolates collected from symptomatic soybean roots across Iowa in 2007 were grown on artificial culture media at five pH levels (4, 5, 6, 7, and 8) and incubated at four temperatures (15, 20, 25, or 30°C). In a rolled-towel assay, soybean seeds from Fo-susceptible cultivar Jack were inoculated with a suspension of a pathogenic or a nonpathogenic Fo isolate; both isolates were previously designated for their relative aggressiveness in causing root rot at 25°C. The seeds were placed in rolled germination paper, and the rolls were incubated in all combinations of buffer solutions at four pH levels (4, 5, 6, and 7), and four temperatures (15, 20, 25, or 30°C). There was a significant interaction between temperature and pH (P < 0.05) for in vitro radial growth and root rot severity. Isolates showed the most in vitro radial growth after incubation at pH 6 and 25°C. For the rolled-towel assay, the pathogenic isolate caused the most severe root rot at pH 6 and 30°C. Gaussian regression analysis estimates for optimal conditions were pH 6.3 at 27.1°C for maximal fungal growth and pH 5.9 at 30°C for maximal root rot severity. These results indicate that optimal pH and temperature conditions are similar for Fo growth and disease in soybean seedlings and suggest that Fo may be a more important seedling pathogen when soybeans are planted under warm conditions in moderately acidic soils.

In vitrorumen fungi growth in a medium containing sodium hydroxide treated wheat straw using competitive PCR assay

2009 ◽  
Vol 2009 ◽  
pp. 174-174
Author(s):  
M H Sakhavati ◽  
T Mohammadabadi ◽  
M Danesh Mesgaran ◽  
M R Nassiry ◽  
A Fani Maleki
Keyword(s):  
Sodium Hydroxide ◽  
Wheat Straw ◽  
Fungal Growth ◽  
Dry Weight ◽  
Competitive Pcr ◽  
Pcr Assay ◽  
Wide Range ◽  
Pure Cultures ◽  
Microbial Attachment

Rumen fungi produce a wide range of polysaccharide degrading enzymes during growth on cell walls and can degrade 0.25 -0.65 of plant tissue dry weight in pure cultures (Orpin, 1983). It has been proposed that sodium hydroxide may break-down hemicellulose and cellulose and expose them to microbial attachment and improve digestibility (Gotoet al., 1993). The aim of the present study was to determinein vitrorumen fungal growth using a quantitative competitive PCR assay (QC-PCR) and dry matter (DM) and neutral detergent fibre (NDF) disappearance from a medium containing untreated (US) or sodium hydroxide treated wheat straw (TS).

scholarly journals An Emerging Strawberry Fungal Disease Associated with Root Rot, Crown Rot and Leaf Spot Caused by Neopestalotiopsis rosae in Mexico

Plant Disease ◽  
2020 ◽  
Vol 104 (8) ◽  
pp. 2054-2059 ◽  
Author(s):  
Angel Rebollar-Alviter ◽  
Hilda Victoria Silva-Rojas ◽  
Dionicio Fuentes-Aragón ◽  
Uriel Acosta-González ◽  
Merari Martínez-Ruiz ◽  
...  
Keyword(s):  
Leaf Spot ◽  
Root Rot ◽  
Phylogenetic Reconstruction ◽  
Elongation Factor ◽  
Fungal Disease ◽  
Crown Rot ◽  
Internal Transcribed Spacer Region ◽  
Pathogenicity Tests ◽  
Vitro Effect

In the 2017 strawberry season, several transplant losses reaching 50% were observed in Zamora, Michoacán Valley, Mexico, due to a new fungal disease associated with root rot, crown rot, and leaf spot. In this year the disease appeared consistently and increased in the following seasons, becoming a concern among strawberry growers. Thus, the aim of this research was to determine the etiology of the disease and to determine the in vitro effect of fungicides on mycelial growth of the pathogen. Fungal isolates were obtained from symptomatic strawberry plants of the cultivars ‘Albion’ and ‘Festival’ and were processed to obtain monoconidial isolates. Detailed morphological analysis was conducted. Concatenated phylogenetic reconstruction was conducted by amplifying and sequencing the translation elongation factor 1 α, β-tubulin partial gene, and the internal transcribed spacer region of rDNA. Pathogenicity tests involving inoculation of leaves and crowns reproduced the same symptoms as those observed in the field, fulfilling Koch’s postulates. Morphology and phylogenetic reconstruction indicated that the causal agent of the described symptoms was Neopestalotiopsis rosae, marking the first report anywhere in the world of this species infecting strawberry. N. rosae was sensitive to cyprodinil + fludioxonil, captan, iprodione, difenoconazole, and prochloraz.

The in vitro effect of allelopathy and various fungi on marsh reed grass (Calamagrostis canadensis)

1997 ◽  
Vol 75 (2) ◽  
pp. 236-241 ◽  
Author(s):  
Richard S. Winder
Keyword(s):  
Biological Control ◽  
Weed Biological Control ◽  
Factors Affecting ◽  
Calamagrostis Canadensis ◽  
Potential Biocontrol Agent ◽  
Agar Media ◽  
Fusarium Sp ◽  
Vitro Effect ◽  
Allelopathic Compounds

Allelopathy and endophytic fungi were evaluated as factors affecting the biological control of marsh reed grass, Calamagrostis canadensis (Michx.) Beauv., a weed of boreal reforestation areas. Leachate from marsh reed grass straw inhibited root growth into liquid and agar media and increased foliar necrosis. Most seedlings harboring endophytic species of Fusarium and Chaetomium were healthy in agar controls, but all such seedlings were diseased when grown in agar with straw leachate. The straw leachate and various fungi had distinct impacts on the virulence of Colletotrichum sp., a potential biocontrol agent for marsh reed grass. In comparisons of control and allelopathic media, Colletotrichum sp. stimulated the overall vigor of reed grass while reducing vigor in the allelopathic medium. Individual isolates of fungi in the genera Epicoccum, Drechslera, and Fusarium were uniformly antagonistic to Colletotrichum, whereas antagonism in individual isolates of Chaetomium, Alternaria, and Stemphylium depended on the presence or absence of allelopathy. Another Fusarium isolate increased the virulence of Colletotrichum sp. in both media, as did two applications of Colletotrichum sp. Allelopathic compounds, Fusarium sp., and Colletotrichum sp. are potential components of a strategy for biological control of marsh reed grass. Key words: weed, biological control, bioherbicide, mycoherbicide.

scholarly journals Antimicrobial activity of endophytic fungus Fusarium sp. isolated from medicinal honeysuckle plant

2016 ◽  
Vol 68 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Huiru Zhang ◽  
Xinchen Sun ◽  
Chunping Xu
Keyword(s):  
Antimicrobial Activity ◽  
Endophytic Fungus ◽  
Pathogenic Bacteria ◽  
New Drugs ◽  
Bioactive Metabolites ◽  
Gel Chromatography ◽  
Physiological Characterization ◽  
Wide Range ◽  
Fusarium Sp

Endophytes of plants have a wide range of strains comprising important sources of various bioactive metabolites. An endophytic fungus was isolated from honeysuckle, an important Chinese medicinal plant. The phylogenetic and physiological characterization indicated that the isolated strain JY2corresponded to Fusarium sp. The culture filtrate of JY2displayed antagonism activity against some pathogenic bacteria owing to the existence of antimicrobial compounds. The filtrate revealed the strongest in vitro antimicrobial activity on Pseudomonas aeruginosa by increasing the permeability of cell membranes. The antibacterial extract was fractionated and purifiedusing silica gel chromatography. Five different bioactive compounds were isolated by bioactivity-guided fractionation from the culture extracts of JY2, and preliminarily identified by HPLC-MS spectral data. These results suggest that Fusarium sp. features a potentially remarkable antimicrobial activity and could be valuable to discover the new drugs or agents for antimicrobial purposes.

scholarly journals COMPARATIVE ASSESSMENT OF FUNGICIDAL ACTIVITY OF PREPARATIONS FOR PRESOWING TREATMENT OF WINTER WHEAT

2021 ◽  
Vol 4 (28) ◽  
pp. 149-158
Author(s):  
N.M. Sidorov ◽  
◽  
E.A. Gyrnets ◽  
M.M. Astakhov ◽  
K.Yu. Saenko ◽  
...  
Keyword(s):  
Root Rot ◽  
Seed Treatment ◽  
Fungal Pathogens ◽  
Fungicidal Activity ◽  
Plant Protection ◽  
Aerial Mycelium ◽  
Plant Protection Products ◽  
Inhibitory Effect ◽  
Wide Range

The massive use of one-component fungicides has caused the problem of the emergence of resistant forms of phytopathogens. The development of multicomponent plant protection products is one of the ways of dealing with such a situation. The aim of the study is to determine the effectiveness of multicomponent chemical dressing agents in suppressing the most common fungal pathogens and seed infections in vitro. This work was performed in 2020 in the Federal Research Center for Biological Plant Protection (Krasnodar) in the laboratory of the creation of microbiological plant protection products and a collection of microorganisms. Fungi of the Fusarium, Microdochium, Bipolaris, Alternaria, Penicillium, Rhizoctonia, Septoria, Pyrenophora genera were used as test objects. The fungicidal activity of chemical preparations against economically significant phytopathogens causing root rot was evaluated in laboratory conditions by the method of serial dilutions followed by sowing on a nutrient medium. In addition, the effectiveness of the preparations was investigated by the method of treated seeds phytoexamination according to GOST 12044–93. The preparations, which included triazoles and phenylpyrroles, had the strongest inhibitory effect (100 %) on pathogens of Rhizoctonia, helminthosporiosis and septoria. The preparation containing compounds of the group of triazoles and strobilurins suppressed the growth of Rhizoctonia solani only. The preparations’ inhibitory effect on a number of phytopathogenic fungi was manifested in growth retardation, absence of aerial mycelium development and mycelium pigmentation. Concerning the causative agents of Fusarium root rot, the two-component preparations efficacy ranged from 51 % to 74.4 %; three-component one – from 42.9 % to 84.7 % depending on the species of the genus Fusarium. Presowing seed treatment made it possible to inhibit the growth of fungi of the genera Fusarium, Mucor, Aspergillus; significantly inhibit the development of the fungus Alternaria (spread in the experimental variant – 1.7 %, in the control variant – 46.7 %). From the data obtained, it can be concluded that multicomponent preparations based on triazoles and phenylpyrroles are highly effective in suppressing a wide range of phytopathogens and can be recommended for presowing seed treatment.

scholarly journals Pathogenicity and chemical control of Alternaria sp. on date palm (Phoenix dactylifera L.)

2021 ◽  
Vol 8 (2) ◽  
pp. 386-391
Author(s):  
Abdulnabi Abbdul Ameer Matrood ◽  
Claudia Adriana Ramírez Valdespino ◽  
Muhannad Abdulridha Al-Waeli ◽  
Mohammad Imad Khrieba ◽  
Abdelhak Rhouma
Keyword(s):  
Chemical Control ◽  
Date Palm ◽  
Management Strategies ◽  
Severity Index ◽  
Phoenix Dactylifera ◽  
Wide Range ◽  
Alternaria Sp ◽  
Fusarium Sp

Recently, a wide range of symptoms including light yellow lesions gradually turning into brown stripes were noticed on date palm leaves in Iraq. In this context, the aim of this study were to isolate the phytopathogens associated with these symptoms, evaluate their pathogenicity and assess the efficacy of two fungicides (Score and Pentanol) under in vitro and in vivo conditions. Two fungal species (Alternaria sp. and Fusarium sp.) were isolated from the symptomatic leaves of date palm. The results of pathogenicity tested proved the ability of Alternaria sp. inoculated separately or in combination with Fusarium sp. to infect the leaves of date palm trees with disease severity index (DSI) values of 67.33% and 65.99%, respectively. The effect of Score (88.76%) and Pentanol (82.91%) against Alternaria sp. was examined by poisoned food technique, which leads a significant increase in mycelial growth inhibition (for 300% of commercial recommended dose of fungicide). Test results indicate that prophylactic spraying of date palm leaves with Score or Pentanol effectively controlled Alternaria sp. with DSI values of 22.65% and 17.87%, respectively. To control Alternaria sp. in field within integrated pest management strategies, chemical control using Score or Pentanol should be taken in consideration.

Plasma Microparticles Have Different Effects on Thrombin Generation in Platelet-Rich and Platelet-Poor Plasma.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1760-1760
Author(s):  
Gleb E. Ivanov ◽  
N. Macartney ◽  
E. Stephens ◽  
N. Bowen ◽  
S. Lees ◽  
...  
Keyword(s):  
Thrombin Generation ◽  
Platelet Rich Plasma ◽  
Maximal Velocity ◽  
Physiological Level ◽  
Wide Range ◽  
Coagulation Tests ◽  
Platelet Concentration ◽  
Vitro Effect ◽  
Free Plasma

Abstract Circulating peripheral blood microparticles (MPs) of various cell origin have been described and measured in physiological and a wide range of pathological conditions. MPs are likely to play a role in coagulation either by exposure of procoagulant phospholipids or expression of tissue factor (TF), but the degree of this contribution to global haemostasis is not yet clear. We studied thrombin generation (TG) parameters (lag, peak thrombin, initial velocity (Vini) and maximal velocity (Vmax) in platelet-free (PFP) and platelet-rich plasma (PRP) of normal volunteers (n=9) in presence of corn trypsin inhibitor, using calibrated automated thrombography (CAT). MP-rich plasma was prepared by ultracentrifugation of PFP and reconstitution of pelleted MPs in a reduced volume of autologous MP-free plasma. TG was also measured in MP-depleted supernatant and platelet-free plasma (PFP) filtered through 0.1 μm filter. In MP-rich plasma, triggered with 5pM TF, with no addition of exogenous phospholipids, we found significantly increased peak TG, compared with PFP and supernatant (70.8 +/− 6.3 vs 51.4 +/− 5.0 vs 28.4 +/− 2.2 nM/L thrombin, p=0.024 and p<0.0001 respectively). MP-rich fraction also produced raised Vini (10.3 +/− 0.9 vs 5.0 +/− 0.6 thrombin nM/L/min, p=0.019) and Vmax (18.3 +/− 2.4 vs 6.8 +/− 1.0 thrombin nM/L/min, p=0.004) compared with MP-depleted supernatant. Ultracentrifugation resulted in reduction of peak TG almost by half, compared with native PFP. The augmenting effect of MP-rich plasma on thrombin peak and velocity was shown to be abolished by filtration. In our experiments removal of MPs by filtration of PFP did not affect routine clinical coagulation tests, but resulted in a significant reduction of peak TG (from 51.4 +/− 5.0 to 23.9 +/− 1.4 thrombin nM, p=0.0002), Vini (from 10.2 +/− 0.4 to 5.6 +/− 0.6, p=0.02) and Vmax (from 15.2 +/− 1.8 to 5.9 +/− 0.2, p=0.02) as compared to PFP. In order to assess the contribution of MPs to TG in presence of platelets, MP-rich plasma was added to various dilutions of PRP, using low concentration of TF (0.5pM) as a trigger. Interestingly, addition of MP-rich fraction only marginally augmented PRP with a platelet concentration of 150x109/L, but the enhancement of peak and velocity of TG became more pronounced when platelet concentration was reduced to 1.5x109/L. In a separate set of experiments, we studied TG in PRP in which MP concentration was reduced by dilution with filtered MP-free plasma as compared to PRP diluted with MP-containing PFP. Reduction in PRP MP content did not lead to a significant decrease in TG even at a low platelet concentration (1.5x109/L), when MP concentration was reduced to about 100 times below the physiological level. Our results indicate that MPs contained in PFP of normal donors significantly affect thrombin generation peak and velocity when compared to PFP in which MPs were eliminated by either ultracentifugation or filtration. The in vitro effect of an increased number of MPs on TG is less noticeable in presence of near-physiological platelet count, but contribution of MPs to TG at low platelet concentrations may potentially protect from bleeding in thrombocytopenic states and explain differences in bleeding phenotype. CAT measurement of TG in MP-rich vs MP-poor plasma could serve as a useful tool in assessing these differences.

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