scholarly journals Transmission of Microdochium albescens from seeds to seedlings in the pre-germinated cultivation system of irrigated rice

2020 ◽  
Vol 50 (2) ◽  
Author(s):  
Bruno Tabarelli Scheidt ◽  
Jaquelini Garcia ◽  
Ricardo Trezzi Casa ◽  
Cileide Maria Medeiros Coelho ◽  
Amauri Bogo ◽  
...  
Keyword(s):  
Culture Medium ◽  
Rice Seedlings ◽  
Untreated Seed ◽  
Agar Culture ◽  
Irrigated Rice ◽  
Cultivation System ◽  
True Leaf ◽  
Seed System ◽  
Water Saturated ◽  
Potato Sucrose Agar

ABSTRACT: The fungus Microdochium albescens is one of the main pathogens associated with irrigated rice seeds in southern Brazil. The objective of the present study was to quantify the transmission of M. albescens from naturally infected seeds to the crown, coleoptile, and first true leaf of the seedlings of six cultivars growing in pre-germinated cultivation system of irrigated rice. Seeding was carried out on a water-saturated substrate, using four untreated seed lots for each of the six cultivars. At 14 days after sowing, the crown, coleoptile, and first true leaf of the seedlings were carefully highlighted, and the samples were disinfected and plated onto potato-sucrose-agar culture medium. M. albescens was transmitted asymptomatically to crown, coleoptile, and first true leaf, at rates of 39.3%, 25.8%, and 5.4%, respectively (these values represent the average incidence of the six cultivars). This is the first report that proves that M. albescens is transmitted from infected seeds to irrigated rice seedlings in a pre-germinated seed system.

scholarly journals Fungi on irrigated rice seeds produced in the pre-germinated system in the Alto Vale do Itajaí region, Santa Catarina state, Brazil

2020 ◽  
Vol 50 (8) ◽  
Author(s):  
Bruno Tabarelli Scheidt ◽  
Juliano Berghetti ◽  
Flávio Chupel Martins ◽  
Ricardo Trezzi Casa ◽  
Welliton Recalcatti ◽  
...  
Keyword(s):  
Culture Medium ◽  
Bipolaris Oryzae ◽  
Santa Catarina ◽  
Agar Culture ◽  
Irrigated Rice ◽  
Rice Seeds ◽  
Potato Sucrose Agar ◽  
Santa Catarina State

ABSTRACT: The aim of this research was to identify and quantify fungi infecting irrigated rice seeds produced in the 2015/16, 2016/17 and 2017/18 harvests in the pre-germinated system in the Alto Vale do Itajaí Region, Santa Catarina State, Brazil. A total of 479 lots of eight cultivars were analyzed. Seeds were disinfected and sown in potato-sucrose-agar culture medium with incubation for seven days at 25ºC ± 2ºC and photoperiod of 12 hours. The main fungus detected in the three crops season was Microdochium albescens with 54.9% of average incidence, followed by Alternaria padwikii (7.7%) and Bipolaris oryzae (3.3%).

scholarly journals Control of Microdochium albescens in pre-germinated and dryland rice seeds

2022 ◽  
Vol 52 (4) ◽  
Author(s):  
Bruno Tabarelli Scheidt ◽  
Evandro Zacca Ferreira ◽  
Flávio Chupel Martins ◽  
Juliano Berghetti ◽  
Marília Michalski De Pieri ◽  
...  
Keyword(s):  
Seed Germination ◽  
Seed Treatment ◽  
Culture Medium ◽  
Rice Seedlings ◽  
Germination Test ◽  
Thiophanate Methyl ◽  
Fungicide Treatment ◽  
Cultivation Systems ◽  
Rice Seeds ◽  
Potato Sucrose Agar

ABSTRACT: The fungus Microdochium albescens can interfere in the germination of seeds and in the death of rice seedlings; however, there is not technical indication for its control by seed treatment. This research evaluated the efficiency of fungicides in the treatment of pre-germinated and dryland rice seeds in the control of M. albescens. Seeds of the cultivars, Epagri 109, SCS116 Satoru, SCS121 CL and SCS122 Miura were treated with the following fungicides (g a.i./100 kg of seeds): fluazinam + thiophanate methyl (9.45 + 63), pyraclostrobin + thiophanate methyl (5 + 45), carboxin + thiram (60 + 60), metalaxyl-M + thiabendazole + fludioxonil (3 + 22.5 + 3.75), carbendazim + thiram (45 + 105), carbendazim (45). Seeds without fungicide treatment constituted the control. The treated seeds were sown in potato-sucrose-agar (PSA) culture medium and incubated at 25 ± 2 °C and photoperiod of 12 hours for 14 days. Treated seeds were also submitted to the germination test. Fluazinam + thiophanate methyl and metalaxyl-M + thiabendazole + fludioxonil showed greater control of M. albescens, not differing statistically between them, in the five cultivars and in the two cultivation systems. The tested fungicides provided seed germination above 90% in the four cultivars.

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.

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 Viability and location of Microdochium albescens in irrigated rice seeds produced in pre-germinated cropping system

2021 ◽  
Vol 47 (1) ◽  
pp. 57-59
Author(s):  
Bruno Tabarelli Scheidt ◽  
Juliano Berghetti ◽  
Ricardo Trezzi Casa ◽  
Flávio Chupel Martins ◽  
Weliton Recalcatti ◽  
...  
Keyword(s):  
Culture Medium ◽  
Cropping System ◽  
Seed Storage ◽  
Irrigated Rice ◽  
Rice Seeds

ABSTRACT The aims of this study were to quantify the viability of Microdochium albescens in irrigated rice seeds stored during the time between harvests and to quantify its incidence in the seed structures. Samples of irrigated rice seeds of the cultivars SCS122 Miura and SCS121 CL were monthly collected and stored during the time between harvests 2018/19. Pathology analysis and viability quantification were performed in the laboratory. The location of the fungus in the seeds was determined by separating lemma, palea, endosperm and embryo, with subsequent disinfestation and sowing in culture medium. The fungus M. albescens showed 77.8% seed storage viability for nine months, considering the average of lots and cultivars. Average incidence was 48% in the lemma, 43.7% in the palea, 24.7% in the endosperm and 20.7% in the embryo. The fungus M. albescens remains viable in rice seeds between harvests, while mycelium is detected at a higher incidence in the external tissues of caryopsis.

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 A note on some physical conditions for cultivating Oxyrrhis marina

1959 ◽  
Vol 38 (3) ◽  
pp. 599-604 ◽  
Author(s):  
M. R. Droop
Keyword(s):  
Culture Medium ◽  
Sea Water ◽  
Soil Extract ◽  
Agar Culture ◽  
Wire Loop ◽  
Oxyrrhis Marina ◽  
Physical Conditions ◽  
Series Of Experiments ◽  
Saccharomyces Exiguus

This note concerns a series of experiments to determine the best conditions of salinity, temperature and pH for cultivating the euryhaline phagotrophic dinoflagellate Oxyrrhis marina Dujardin.The strain of Oxyrrhis employed was isolated from a brackish pool at Tvarminne, Finland (Droop, 1953a, b). The culture medium for the experiments contained soil extract and an artificial sea water, SW 1 (NaCl, MgCl26H2O, KCl, and CaSO42H2O in the proportions by weight 15:2.5:0.4:0.5), and for food a small quantity of the yeast Saccharomyces exiguus was administered daily from an agar culture with a wire loop.

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