scholarly journals Effect of Fungicides on Colony Growth of Colletotrichum Lindemuthianum (Sacc. & Magn.) Scrib.

2008 ◽  
Vol 48 (2) ◽  
pp. 201-212
Author(s):  
Juliana Sartori ◽  
Antonio Maringoni
Keyword(s):  
Culture Medium ◽  
High Sensitivity ◽  
Colony Growth ◽  
Potato Dextrose Agar ◽  
Colletotrichum Lindemuthianum ◽  
Cross Resistance ◽  
Agar Culture ◽  
Thiophanate Methyl ◽  
Low Sensitivity

Effect of Fungicides on Colony Growth ofColletotrichum Lindemuthianum(Sacc. & Magn.) Scrib.Colletotrichum lindemuthianum(Sacc. & Magn.) Scrib. is the causal agent of the anthracnose of common bean (Phaseolus vulgarisL.), a fungal disease of a great significance in brazilian bean cultures. The goals of this work were to evaluate thein vitrocolony growth and to determine the ED50interval of twentyC. lindemuthianumisolates from different regions of Brazil to five fungicides of different active ingredients and to some blendings (carbendazim, chlorothalonil, thiophanate-methyl, chlorothalonil + thiophanate-methyl, trifloxystrobin, propiconazole and trifloxystrobin + propiconazole), at concentrations of 0, 1, 10, 100 and 1000 μg/ml, in a potato-dextrose-agar culture medium. The results revealed seven isolates with low sensitivity to carbendazim and thiophanate-methyl (ED50interval greater than 1000 μg/ml) thus suggesting cross-resistance. Isolate sensitivity to chlorothalonil ranged from ED50interval less than 1 μg/ml to greater than 1000 μg/ml. Those isolates with high sensitivity to thiophanate-methyl, ED50interval less than 1 μg/ml, did also show it with respect to chlorothalonil + thiophanate-methyl. Sixteen isolates showed a high sensitivity to trifloxystrobin with a ED50interval less than 1 μg/ml. Nineteen isolates ofC. lindemuthianumshowed high sensitivity to propiconazole and to trifloxystrobin + propiconazole with ED50interval less than 1 μg/ml. Isolates with low sensitivity to carbendazim and thiophanate-methyl were sensitive to propiconazole and to trifloxystrobin + propiconazole. Variability was found in the sensitivity of the colony growth ofC. lindemuthianumisolates from different regions of Brazil to the fungicides evaluated.

scholarly journals Obtaining monokaryotic and dikaryotic mycelial cultures of two Amazonian strains of Geastrum (Geastraceae, Basidiomycota)

2020 ◽  
Vol 50 (1) ◽  
pp. 61-67
Author(s):  
Marcos Diones Ferreira SANTANA ◽  
Ruby VARGAS-ISLA ◽  
Janaina da Costa NOGUEIRA ◽  
Thiago ACCIOLY ◽  
Bianca Denise Barbosa da SILVA ◽  
...  
Keyword(s):  
Culture Medium ◽  
Culture Media ◽  
Brazilian Amazon ◽  
Potato Dextrose Agar ◽  
Morphological Description ◽  
Agar Culture ◽  
Biotechnological Potential ◽  
Sexual Crosses ◽  
High Diversity

ABSTRACT The high diversity of the genus Geastrum and the difficulty of obtaining mycelial cultures impairs the study of the ecophysiology and the exploration of the biotechnological potential of the taxon. In this study, different culture media were tested to obtain mycelial cultures for G. lloydianum and G. subiculosum collected in the Brazilian Amazon. Data on spore germination, and isolation of monokaryotic cultures and in vitro sexual reproduction are presented, as well as a brief morphological description of the cultures obtained. For both species, Potato Dextrose Agar (PDA) was the most promising of the tested culture media. The highest growth in agar culture ever recorded for this genus is reported (4.9 mm per week for G. lloydianum and 7.5 mm for G. subiculosum). In the PDA culture medium, spores germinated after 35-40 days of incubation and the isolation of monokaryotic cultures of the two species, as well as in vitro sexual crosses, were successfully performed.

scholarly journals Efficiency of Blotter test and agar culture medium to detect Fusarium graminearum and Pyricularia grisea in wheat seeds

2017 ◽  
Vol 39 (3) ◽  
pp. 297-302
Author(s):  
Meyriele Pires de Camargo ◽  
Maria Heloisa Duarte de Moraes ◽  
José Otávio Machado Menten
Keyword(s):  
Fusarium Graminearum ◽  
Culture Medium ◽  
Potato Dextrose Agar ◽  
Pyricularia Grisea ◽  
Agar Culture ◽  
Hypochlorite Solution ◽  
Three Samples ◽  
Seed Health ◽  
Incubation Temperatures ◽  
Wheat Seeds

Abstract: Seeds can be considered one of the most efficient forms to disseminate pathogens. Therefore, the use of healthy seeds is extremely important to establish a crop, and seed health testing must be performed to determine the seed sanitary quality. This study aimed to compare the efficiency of seed health testing to detect Pyricularia grisea and Fusarium graminearum in three samples of wheat seeds. Methods evaluated were Blotter test with freezing (BTF) and potato-dextrose-agar culture medium (PDA). The incubation temperatures were 20 ºC and 25 ºC. From each sample, a subsample was submitted to seed asepsis using hypochlorite solution (1%) and another analyzed without seed asepsis. The temperatures evaluated did not influence the detection of the pathogens. P. grisea incidence ranged from 4.5 to 17% with BTF without seed asepsis. The BTF with seed asepsis and PDA (with and without seed asepsis) presented pathogen incidence no higher than 1.5%. Moreover, results suggested that most part of P. grisea inoculum was presented externally on seed tissues. PDA medium was more efficient to detect F. graminearum, independently of seed asepsis. By this method, pathogen incidence ranged from 3 to 39%. F. graminearum incidence using BTF with seed asepsis varied from 0.5 to 1.5% and BTF without seed asepsis presented a pathogen incidence of 5.0 to 12.5%. The Blotter test with freezing was more efficient to detect P. grisea while the PDA medium was more efficient to detect F. graminearum.

scholarly journals Two Mutations in β-Tubulin 2 Gene Associated with Thiophanate-Methyl Resistance in Colletotrichum cereale Isolates from Creeping Bentgrass in Mississippi and Alabama

Plant Disease ◽  
2010 ◽  
Vol 94 (2) ◽  
pp. 207-212 ◽  
Author(s):  
Joseph R. Young ◽  
Maria Tomaso-Peterson ◽  
Karla de la Cerda ◽  
Francis P. Wong
Keyword(s):  
Amino Acid ◽  
Creeping Bentgrass ◽  
Colony Growth ◽  
Amino Acid Sequences ◽  
Common Disease ◽  
Thiophanate Methyl ◽  
Colletotrichum Cereale ◽  
In Vitro Bioassays ◽  
Β Tubulin

Turfgrass anthracnose, caused by Colletotrichum cereale (≡C. graminicola), has become a common disease of creeping bentgrass putting greens during the summer in Mississippi and Alabama over the last 15 years. Thiophanate-methyl is a single-site mode-of-action fungicide applied to control C. cereale. In vitro bioassays were performed to evaluate the sensitivity of 103 isolates to thiophanate-methyl concentrations ranging from 0.039 to 10 μg/ml. Eighty-three isolates were collected from creeping bentgrass in Mississippi and Alabama that had been exposed to thiophanate-methyl. An additional 20 isolates were included from nonexposed turfgrasses. Radial colony growth in amended media was relative to nonamended media for all in vitro bioassays. With thiophanate-methyl at 10 μg/ml, relative growth of exposed isolates ranged from 77.5 to 130.7% with a mean of 99.3% compared with nonexposed, baseline isolates that ranged from 0.0 to 48.7% with a mean of 20.4%. A representative sample of thiophanate-methyl-exposed and nonexposed isolates was used to determine the mechanism of resistance by comparing amino acid sequences of the β-tubulin 2 protein. All of the thiophanate-methyl-exposed isolates that were sequenced had a point mutation resulting in substitutions from glutamic acid to alanine at position 198 or from phenylalanine to tyrosine at position 200 of the β-tubulin 2 protein. These amino acid substitutions in C. cereale isolates from Mississippi and Alabama appear to confer resistance to thiophanate-methyl and differ from those reported previously for this pathogen.

scholarly journals Co-application of Difenoconazole with Thymol Results in Suppression of a Parastagonospora Nodorum Mutant Strain Resistant to this Triazole

2019 ◽  
Author(s):  
M I Kartashov ◽  
L A Shcherbakova ◽  
N V Statsyuk ◽  
V G Dzhavakhiya
Keyword(s):  
Mutant Strain ◽  
In Vitro Study ◽  
Potato Dextrose Agar ◽  
Sensitive Strain ◽  
Resistant Isolate ◽  
Leaf Blotch ◽  
Low Sensitivity ◽  
Parastagonospora Nodorum ◽  
Principal Possibility

Results of in vitro study of thymol, a natural chemosensitizer, as a potential agent for overcoming of difenoconazole resistance of Parastagonospora nodorum causing glume and leaf blotch of wheat are first reported. The level of difenoconazole resistance of a natural mutant PNm1 strain with low sensitivity to the Dividend fungicide (a.i. difenoconazole) was determined by the cultivation of this isolate on potato dextrose agar in the presence of the fungicide at sub-lethal and lethal (in relation to the initial fungicide-sensitive strain) concentrations. A principal possibility of the thymol use to overcome resistance of P. nodorum to DMI (demethylation inhibitors) fungicides is shown. Co-application of this compound with Dividend SC, 3 % resulted in a significant reduction of resistance of the mutant strain and enhancement of its sensitivity to difenoconazole up to the level corresponding to the initial non-resistant isolate.

scholarly journals In Vitro Effect ofZingiber officinaleExtract on Growth ofStreptococcus mutansandStreptococcus sanguinis

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Arash Azizi ◽  
Shabnam Aghayan ◽  
Saeed Zaker ◽  
Mahdieh Shakeri ◽  
Navid Entezari ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Culture Medium ◽  
Zingiber Officinale ◽  
Bacterial Suspension ◽  
Tooth Decay ◽  
Agar Culture ◽  
Solid Agar ◽  
Vitro Effect ◽  
Serial Dilutions

Background and Objectives. Tooth decay is an infectious disease of microbial origin. Considering the increasing prevalence of antibiotic resistance due to their overuse and also their side effects, medicinal plants are now considered for use against bacterial infections. This study aimed to assess the effects of different concentrations ofZingiber officinaleextract on proliferation ofStreptococcus mutansandStreptococcus sanguinisin vitro.Materials and Methods. In this experimental study, serial dilutions of the extract were prepared in two sets of 10 test tubes for each bacterium (total of 20). Standard amounts of bacterial suspension were added; 100ƛof each tube was cultured on prepared solid agar plates and incubated at 37°C for 24 hours. Serial dilutions of the extract were prepared in another 20 tubes and 100ƛof each tube was added to blood agar culture medium while being prepared. The mixture was transferred to the plates. The bacteria were inoculated on plates and incubated as described.Results. The minimum inhibitory concentration (MIC) was 0.02 mg/mL forS. mutansand 0.3 mg/mL forS. sanguinis. The minimum bactericidal concentration (MBC) was 0.04 mg forS. mutansand 0.6 mg forS. sanguinis.Conclusion.Zingiber officinaleextract has significant antibacterial activity againstS. mutansandS. sanguiniscariogenic microorganisms.

scholarly journals In Vitro Qualitative Phytochemical Screening, Tlc-Bioautography and Spot Screening of Bistorta Amplexicaulis (D.DON) Greene Extracts

2021 ◽  
Vol 50 (3) ◽  
pp. 613-622
Author(s):  
Irsa Shafique ◽  
Saiqa Andleeb ◽  
Shaukat Ali ◽  
Rozina Ghulam Mustafa ◽  
Anum Naseer
Keyword(s):  
Biological Activities ◽  
High Sensitivity ◽  
Significant Inhibition ◽  
Screening Methods ◽  
Leaf Extracts ◽  
Tlc Bioautography ◽  
Antioxidant Agents ◽  
Direct Bioautography ◽  
Low Sensitivity

The biological activities of Bistorta amplexicaulis (D.Don) Greene rhizome and leaves extracts were evaluated. In vitro antibacterial activity, direct bioautography, and spot screening of TLC developed bands were investigated against seven bacterial pathogens. Screening of phytochemical constituents was also done through both qualitative and thin layer chromatographic methods. DMSO extracts of rhizome indicated high sensitivity (12.33 ± 1.52 and 11.33 ± 0.57 mm) against Escherichia coli. Whereas methanolic and acetonic extracts of rhizome indicated significant inhibition (11.66 ± 1.15 and 11.33 ± 0.57 mm) of S. marcesscens. All leaf extracts revealed low sensitivity against E. coli. TLC-bioautography and spot screening methods showed the significant use of B. amplexicaulis as an antibacterial agent. Antioxidant activity indicated that acetone and DMSO extracts of rhizome and methanolic leaf extract have maximum scavenging potential. Among the screened phytochemicals, terpenoids, phenols, and quinones were detected in all extracts indicating the potential use of B. amplexicaulis as both antibacterial and antioxidant agents. Bangladesh J. Bot. 50(3): 613-622, 2021 (September)

scholarly journals Variation Among Isolates of Colletotrichum dematium var. truncata from Soybean and Three Colletotrichum spp. to Benomyl

1969 ◽  
Vol 66 (1) ◽  
pp. 35-43
Author(s):  
A. Rodríguez-Marcano ◽  
J. B. Sinclair
Keyword(s):  
Fungal Pathogen ◽  
Radial Growth ◽  
Growing Season ◽  
Colony Growth ◽  
Spore Production ◽  
Potato Dextrose Agar ◽  
Southern Illinois ◽  
Colletotrichum Dematium ◽  
Colletotrichum Spp

Three isolates of the fungal pathogen Colletotrichum dematium var. truncata were obtained from soybean (Glycine max) during the 1975 growing season in central and southern Illinois and labeled Cd-1, Cd-2 and Cd-3. The three isolates produced curved conidia measuring between 17.8 to 23.3 µ long and 3.2 to 5.1 µ wide. Growth rate and spore production were variable among the three isolates with Cd-3 producing the most spores per cm2 of colony growth and Cd-2 producing the largest colony growth at 25° C. Isolate Cd-1, found to be tolerant to benomyl in vitro, showed a uniform radial-growth pattern on potato-dextrose agar amended with 1 to 350 µg/ml commercial benomyl, while isolates Cd-2 and Cd-3 showed a bimodal-type growth curve. Colletotrichum glycine and Coltetotrichum musae were sensitive to benomyl.

scholarly journals Comparison of methods for the quantification of cell-free DNA isolated from cell culture supernatant

Tumor Biology ◽  
2019 ◽  
Vol 41 (8) ◽  
pp. 101042831986636 ◽  
Author(s):  
Abel Jacobus Bronkhorst ◽  
Vida Ungerer ◽  
Stefan Holdenrieder
Keyword(s):  
Cell Culture ◽  
Culture Medium ◽  
Culture Supernatant ◽  
Quantitative Polymerase Chain Reaction ◽  
High Sensitivity ◽  
Cell Types ◽  
Cell Culture Supernatant ◽  
Cell Free Dna ◽  
Free Dna

Gaining a better understanding of the biological properties of cell-free DNA constitutes an important step in the development of clinically meaningful cell-free DNA–based tests. Since the in vivo characterization of cell-free DNA is complicated by the immense heterogeneity of blood samples, an increasing number of in vitro cell culture experiments, which offer a greater level of control, are being conducted. However, cell culture studies are currently faced with three notable caveats. First, the concentration of cell-free DNA in vitro is relatively low. Second, the median amount and size of cell-free DNA in culture medium varies greatly between cell types. Third, the amount and size of cell-free DNA in the culture medium of a single cell line fluctuates over time. Although these are interesting findings, it can also be a great source of experimental confusion and emphasizes the importance of method optimization and standardization. Therefore, in this study, we compared five commonly used cell-free DNA quantification methods, including quantitative polymerase chain reaction, Qubit Double-Stranded DNA High Sensitivity assay, Quant-iT PicoGreen Assay, Bioanalyzer High Sensitivity DNA assay, and NanoDrop Onec. Analysis of the resulting data, along with an interpretation of theoretical values (i.e. the theoretical detection and quantification limits of the respective methods), enables the calculation of optimal conditions for several important preanalytical steps pertaining to each quantification method and different cell types, including the (1) time-point at which culture medium should be collected for cell-free DNA extraction, (2) amount of cell culture supernatant from which to isolate cell-free DNA, (3) volume of elution buffer, and (4) volume of cell-free DNA sample to use for quantification.

Dexamethasone-induced increase in in vitro clonogenicity of human neoplasms.

1984 ◽  
Vol 2 (8) ◽  
pp. 944-947 ◽  
Author(s):  
J C Sloman ◽  
M J Murphy
Keyword(s):  
Culture Medium ◽  
Human Tumor ◽  
Colony Growth ◽  
Dose Response Relationship ◽  
Hormone Effect ◽  
Minimum Number ◽  
Corticosteroid Receptor ◽  
The Mean ◽  
Corticosteroid Hormone

The addition of the corticosteroid hormone, dexamethasone, to the culture medium results in a significant enhancement of tumor colony growth in the human tumor clonogenic assay. Taking 20 as the mean minimum number of colonies per dish that allows evaluation of 122 cultured tumors, 67 were fully evaluable in the presence of dexamethasone whereas only 34 were evaluable when it was omitted. The addition of dexamethasone significantly (P less than .05) increased the number of evaluable tumors by 23. Tumors cultured included those of the breast, lung, colon, ovary, kidney, and stomach. The response to dexamethasone showed a dose-response relationship over a concentration range typical of corticosteroid receptor-mediated reactions, and it appeared to be steroid specific. Possible mechanisms for this hormone effect are discussed.

scholarly journals Sensitivity loss by Corynespora cassiicola, isolated from soybean, to the fungicide carbendazim

2014 ◽  
Vol 40 (3) ◽  
pp. 273-276 ◽  
Author(s):  
Aveline Avozani ◽  
Erlei Melo Reis ◽  
Rosane Baldiga Tonin
Keyword(s):  
Mycelial Growth ◽  
Culture Medium ◽  
Potato Dextrose Agar ◽  
Controlled Environment ◽  
Corynespora Cassiicola ◽  
Sensitivity Loss ◽  
West Region ◽  
Environment Temperature ◽  
Control Failure

Soybean target leaf spot, caused by the fungus Corynespora cassiicola, is controlled especially by leaf application of fungicides. In the last seasons, in the central-west region of Brazil, the disease chemical control efficiency has been low. This led to the hypothesis that the control failure could be due to the reduction or loss of the fungus sensitivity to fungicides. To clarify this fact, in vitro experiments were conducted to determine mycelial sensitivity of five C. cassiicola isolates to fungicides. Mycelial growth was assessed based on the growth of the mycelium on the culture medium, in Petri dishes. The medium potato-dextrose-agar was supplemented with the concentrations 0; 0.01; 0.1; 1; 10; 20 and 40 mg/L of the active ingredients carbendazim, cyproconazole, epoxiconazole, flutriafol and tebuconazole. The experiment was conducted and repeated twice in a controlled environment, temperature of 25±2ºC and photoperiod of 12 hours. Data on the percentage of mycelial inhibition were subjected to logarithmic regression analysis and the concentration that inhibits 50% of the mycelial growth (IC50) was calculated. Loss of sensitivity to carbendazim was observed for three fungal isolates, IC50 > 40 mg/L. Considering all five isolates, the IC50 for tebuconazole ranged from 1.89 to 2.80 mg/L, for epoxiconazol from 2.25 to 2.91, for cyproconazole from 9.21 to 20.32 mg/L, and for flutriafol from 0.77 to 2.18 mg/L. In the absence of information on the reference IC50 determined for wild isolates, the lowest values generated in our study can be used as standard to monitor the fungus sensitivity.

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