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 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 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 Characterization and optimization of extracellular enzymes production by Aspergillus niger strains isolated from date by-products

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Reda Bellaouchi ◽  
Houssam Abouloifa ◽  
Yahya Rokni ◽  
Amina Hasnaoui ◽  
Nabil Ghabbour ◽  
...  
Keyword(s):  
Aspergillus Niger ◽  
Culture Medium ◽  
Extracellular Enzymes ◽  
Enzyme Expression ◽  
Specific Enzyme ◽  
Enzymatic Production ◽  
High Production Rate ◽  
High Production ◽  
Incubation Temperatures ◽  
By Products

Abstract Background This work aims to study the optimal conditions of the fermentation culture medium used for the production of extracellular enzymes (amylase, cellulase, lipase, and protease) from previously isolated Aspergillus niger strains in date by-products. Results The five most powerful isolates selected based on the zone of degradation formed on Petri plates by the substrate were subjected to the quantitative evaluation of their enzymatic production. All five strains showed almost similar API-ZYM profiles, with minor variations observed at the level of some specific enzyme expression. The production of cellulase and amylase was depending on pH and incubation temperatures. ASP2 strain demonstrated the high production rate of amylase (at pH 5 and 30 °C) and cellulase (at pH 6 and 30 °C) for 96 h of incubation. Conclusion The A. niger showed the ability to produce several extracellular enzymes and can be used in the valorization of different agroindustrial residues.

Chemical control of fungal growth and ochratoxin A production by Aspergillus isolated from Moroccan grapes

2018 ◽  
Vol 7 (2) ◽  
pp. 84-91
Author(s):  
Adil Laaziz ◽  
Souad Qjidaa ◽  
Yousra El Hammoudi ◽  
Abdelouahed Hajjaji ◽  
Amina Bouseta
Keyword(s):  
Ochratoxin A ◽  
Radial Growth ◽  
Culture Medium ◽  
Fungal Growth ◽  
Sublethal Concentration ◽  
Agar Culture ◽  
Total Inhibition ◽  
Yeast Autolysate ◽  
Germination And Growth ◽  
Czapek Yeast Autolysate Agar

The aim of this study was to evaluate the effect of three fungicides azoxystrobin (Ortiva), hexaconazole (Hexa) and pyrimethanil (Pyrus) for their ability to inhibit the radial growth and ochratoxin A (OTA) production by five ochratoxigenic strains of Aspergillus carbonarius and A. niger previously iso-lated from Moroccan grapes. Our results showed that, the addition of the fungicides to the Czapek Yeast Autolysate agar culture medium reduced the growth of the ochratoxigenic strains. Pyrimethanil caused total inhibition of spore germination and growth of the five strains, for all dose tested. Where-as hexaconazole totally inhibited the growth of 4 strains and gave growth for the MUCL 49227 strain (2.67 mm/day) at sublethal concentration. The reduction in radial growth was less marked for azoxystrobin, with growth rate varying between 0 and 6.37 mm/day depending on the strain and the azoxystrobin concentration. Analysis of variance showed that the effect of single factors (fungicides, concentration and strain) and their interactions on growth and OTA production were highly significant (P=0.000).These findings suggest that the use of tested fungicides have to potential for reduction in production of OTA.

Two-Day Yeast and Mold Enumeration Using the ISO-GRID® Membrane Filtration System in Conjunction with YM-11 Agar

1996 ◽  
Vol 59 (4) ◽  
pp. 416-419 ◽  
Author(s):  
PHYLLIS ENTIS ◽  
IRINA LERNER
Keyword(s):  
Membrane Filtration ◽  
Culture Medium ◽  
Food Product ◽  
Food Samples ◽  
Potato Dextrose Agar ◽  
Plate Method ◽  
Product Categories ◽  
Filtration System ◽  
Pure Cultures ◽  
Yeasts And Molds

A 2-day yeast and mold enumeration procedure using the ISO-GRID® membrane filtration system in conjunction with a new culture medium, YM-11 agar, was compared to the conventional 5-day pour plate method using antibiotic-supplemented potato dextrose agar. Performance of the new method was evaluated using both pure cultures of yeasts and molds and 275 food samples, representing 25 different food products. The 2-day ISO-GRID® method yielded counts equivalent to or significantly higher than the 5-day pour plate method in 23 of the 25 food product categories.

Effects of Culture Media, Exposure Time and Temperature on Near-Ultraviolet-Induced Sporulation of Alternaria alternata

1985 ◽  
Vol 48 (4) ◽  
pp. 316-319
Author(s):  
CHENG-I WEI ◽  
DIANE D. SWARTZ ◽  
JOHN A. CORNELL
Keyword(s):  
Exposure Time ◽  
Alternaria Alternata ◽  
Culture Medium ◽  
Culture Media ◽  
Media Exposure ◽  
Potato Dextrose Agar ◽  
Uv Exposure ◽  
Strain Atcc ◽  
Ultraviolet Exposure ◽  
Near Ultraviolet

Effects of culture media, near-ultraviolet exposure time, and temperature on sporulation of Alternaria alternata were investigated. Strains RL 671-2 and ATCC 36068 were cultivated on Potato Dextrose Agar (PDA), V8 Juice Agar (V8 Agar) and Mycological Agar (MA). The best culture medium for sporulation of strain RL 671-2 was PDA, followed by V8 agar, with only negligible numbers of spores appearing on MA. Near-UV exposure significantly increased sporulation in strain RL 671-2 on PDA and V8 agar. Significantly higher (P<0.01) spore counts were found in PDA cultures of this strain exposed to near-UV at 35 than at 20°C. On V8 agar significantly more spores were observed at 20 than at 35°C. MA was not a satisfactory medium for sporulation of ATCC 36068. Both PDA and V8 agar equally supported sporulation for this strain (ATCC 36068) at all exposure times.

scholarly journals Comparison of the Fungistatic Activity of Selected Essential Oils Relative to Fusarium graminearum Isolates

Molecules ◽  
2019 ◽  
Vol 24 (2) ◽  
pp. 311 ◽  
Author(s):  
Teresa Krzyśko-Łupicka ◽  
Weronika Walkowiak ◽  
Marietta Białoń
Keyword(s):  
Chemical Composition ◽  
Growth Inhibition ◽  
Fusarium Graminearum ◽  
Linear Growth ◽  
Growth Index ◽  
Potato Dextrose Agar ◽  
Fungistatic Activity ◽  
Lemon Oil ◽  
Rosemary Oil ◽  
Fungal Colony

The aim of the study was to determine the chemical composition of lemon, rosewood, geranium and rosemary oils, and compare their effect on the sensitivity of Fusarium graminearum ZALF 24 and Fusarium graminearum ZALF 339 isolated from infected cereals. The tested oils were added to Potato Dextrose Agar (PDA) medium at concentrations of 0.125%, 0.25%, 0.5%, 1.0% and 2.0%. The activity of the oils on inhibition of the linear growth of mycelium was evaluated by measuring the growth of fungal colonies (growth index), while the fungistatic activity was evaluated on the basis of the percentage growth inhibition of a fungal colony and calculated according to Abbott’s formula. The sensitivity of the test strains was variable and depended on the type and concentration of the tested oils. Geranium and rosewood oils in all of the concentrations completely inhibited the growth of the used isolates. In contrast, lemon oil relative to F. graminearum ZALF 339 showed the highest activity at a concentration of 1.0% and rosemary oil, 0.5%. The highest activity against F. graminearum ZALF 24 was shown by the oils of rosemary and lemon at concentrations from 1.0% to 2.0%. The susceptibility of Fusarium graminearum isolates was differentiated and depended on the type and concentration of tested oils.

FUNGI IN FOODS--I. EFFECT OF INHIBITOR AND INCUBATION TEMPERATURE ON ENUMERATION1

1970 ◽  
Vol 33 (10) ◽  
pp. 433-434 ◽  
Author(s):  
John A. Koburger
Keyword(s):  
Incubation Temperature ◽  
Potato Dextrose Agar ◽  
Incubation Temperatures ◽  
Growth Of Bacteria

Antibiotics were far superior to acidification for controlling bacteria when counting fungi in foods. Yeast and mold counts from Potato Dextrose Agar containing antibiotics were much higher than those obtained in the acidified medium, and growth of bacteria was never a problem. When incubation temperatures of 32 and 22 C were compared, more colonies appeared at 22 C.

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