Assay of the inhibitory effect of pentachlorophenol and formaldehyde on mycelial growth and development of reproductive structures inAspergillus niger

1999 ◽  
Vol 44 (5) ◽  
pp. 519-522 ◽  
Author(s):  
M. T. Bomar ◽  
M. Bomar
Keyword(s):  
Growth And Development ◽  
Mycelial Growth ◽  
Inhibitory Effect ◽  
Reproductive Structures

scholarly journals Diffusible Compounds Produced by Hanseniaspora osmophila and Gluconobacter cerinus Help to Control the Causal Agents of Gray Rot and Summer Bunch Rot of Table Grapes

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 664
Author(s):  
Matías Olivera ◽  
Ninoska Delgado ◽  
Fabiola Cádiz ◽  
Natalia Riquelme ◽  
Iván Montenegro ◽  
...  
Keyword(s):  
Mycelial Growth ◽  
Inhibitory Effect ◽  
Biocontrol Agents ◽  
Environmental Cost ◽  
Antifungal Compounds ◽  
Table Grapes ◽  
Dual Cultures ◽  
Bunch Rot ◽  
Direct Bioautography

Gray and summer bunch rot are important diseases of table grapes due to the high economic and environmental cost of their control with synthetic fungicides. The ability to produce antifungal compounds against the causal agents Botrytis, Aspergillus, Penicillium, and Rhizopus of two microorganisms isolated from table grapes and identified as Hanseniaspora osmophila and Gluconobacter cerinus was evaluated. In dual cultures, both biocontrol agents (together and separately) inhibited in vitro mycelial growth of these pathogens. To identify the compounds responsible for the inhibitory effect, extractions were carried out with organic solvents from biocontrol agents separately. Through dual cultures with pathogens and pure extracts, only the hexane extract from H. osmophila showed an inhibitory effect against Botrytis cinerea. To further identify these compounds, the direct bioautography technique was used. This technique made it possible to determine the band displaying antifungal activity at Rf = 0.05–0.2. The compounds present in this band were identified by GC-MS and compared to the NIST library. The most abundant compounds, not previously reported, corresponded to alkanes, ketones, alcohols, and terpenoids. H. osmophila and G. cerinus have the potential to control the causal agents of gray and summer bunch rot of table grapes.

scholarly journals Brassinolide Enhances the Level of Brassinosteroids, Protein, Pigments, and Monosaccharides in Wolffia arrhiza Treated with Brassinazole

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1311
Author(s):  
Magdalena Chmur ◽  
Andrzej Bajguz
Keyword(s):  
Plant Growth ◽  
Growth And Development ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
Plant Growth And Development ◽  
Concentration Dependent Manner ◽  
Spectrophotometric Methods ◽  
Synthetic Inhibitor ◽  
Wolffia Arrhiza ◽  
First Time

Brassinolide (BL) represents brassinosteroids (BRs)—a group of phytohormones that are essential for plant growth and development. Brassinazole (Brz) is as a synthetic inhibitor of BRs’ biosynthesis. In the present study, the responses of Wolffia arrhiza to the treatment with BL, Brz, and the combination of BL with Brz were analyzed. The analysis of BRs and Brz was performed using LC-MS/MS. The photosynthetic pigments (chlorophylls, carotenes, and xanthophylls) levels were determined using HPLC, but protein and monosaccharides level using spectrophotometric methods. The obtained results indicated that BL and Brz influence W. arrhiza cultures in a concentration-dependent manner. The most stimulatory effects on the growth, level of BRs (BL, 24-epibrassinolide, 28-homobrassinolide, 28-norbrassinolide, catasterone, castasterone, 24-epicastasterone, typhasterol, and 6-deoxytyphasterol), and the content of pigments, protein, and monosaccharides, were observed in plants treated with 0.1 µM BL. Whereas the application of 1 µM and 10 µM Brz caused a significant decrease in duckweed weight and level of targeted compounds. Application of BL caused the mitigation of the Brz inhibitory effect and enhanced the BR level in duckweed treated with Brz. The level of BRs was reported for the first time in duckweed treated with BL and/or Brz.

scholarly journals Induction of Soil Suppressiveness Against Rhizoctonia solani by Incorporation of Dried Plant Residues into Soil

2006 ◽  
Vol 96 (12) ◽  
pp. 1372-1379 ◽  
Author(s):  
Masahiro Kasuya ◽  
Andriantsoa R. Olivier ◽  
Yoko Ota ◽  
Motoaki Tojo ◽  
Hitoshi Honjo ◽  
...  
Keyword(s):  
Rhizoctonia Solani ◽  
Mycelial Growth ◽  
Inhibitory Effect ◽  
Volatile Substance ◽  
Disease Suppression ◽  
Plant Residues ◽  
Infested Soil ◽  
Antagonistic Bacteria ◽  
Damping Off ◽  
Soil Suppressiveness

Suppressive effects of soil amendment with residues of 12 cultivars of Brassica rapa on damping-off of sugar beet were evaluated in soils infested with Rhizoctonia solani. Residues of clover and peanut were tested as noncruciferous controls. The incidence of damping-off was significantly and consistently suppressed in the soils amended with residues of clover, peanut, and B. rapa subsp. rapifera ‘Saori’, but only the volatile substance produced from water-imbibed residue of cv. Saori exhibited a distinct inhibitory effect on mycelial growth of R. solani. Nonetheless, disease suppression in such residue-amended soils was diminished or nullified when antibacterial antibiotics were applied to the soils, suggesting that proliferation of antagonistic bacteria resident to the soils were responsible for disease suppression. When the seed (pericarps) colonized by R. solani in the infested soil without residues were replanted into the soils amended with such residues, damping-off was suppressed in all cases. In contrast, when seed that had been colonized by microorganisms in the soils containing the residues were replanted into the infested soil, damping-off was not suppressed. The evidence indicates that the laimosphere, but not the spermosphere, is the site for the antagonistic microbial interaction, which is the chief principle of soil suppressiveness against Rhizoctonia damping-off.

scholarly journals Fungicidal effect of silver nanoparticles on toxigenic fungi in cocoa

2016 ◽  
Vol 51 (12) ◽  
pp. 1929-1936 ◽  
Author(s):  
Raquel Villamizar-Gallardo ◽  
Johann Faccelo Osma Cruz ◽  
Oscar Orlando Ortíz-Rodriguez
Keyword(s):  
Silver Nanoparticles ◽  
Fusarium Solani ◽  
Theobroma Cacao ◽  
Mycelial Growth ◽  
Culture Media ◽  
Fungal Growth ◽  
Inhibitory Effect ◽  
Plant Tissues ◽  
Inhibition Effect ◽  
Toxigenic Fungi

Abstract: The objective of this work was to evaluate the microbicidal effect of silver nanoparticles (AgNPs) on potentially toxigenic fungi affecting cocoa (Theobroma cacao) crops. These fungi, isolated from diseased cocoa pods, were characterized phenotypically and genotypically. The microbicidal effect was assessed by measuring radial mycelial growth, in synthetic culture media, and at different AgNP concentrations in plant tissues. The inhibition effect was monitored in Petri dishes, and changes in fungal structures were observed through scanning electron microscopy. Two potentially toxigenic fungi were highly prevalent: Aspergillus flavus and Fusarium solani. The inhibition assays, performed in liquid and solid synthetic culture media, showed that AgNPs did not significantly affect the growth of these fungi, even at the highest concentration (100 ppm). By contrast, they showed a positive inhibitory effect in plant tissues, especially in the cortex, when infected with A. flavus, in which an 80 ppm dose completely inhibited fungal growth. However, once fungi have managed to penetrate inside the pods, their growth is unavoidable, and AgNP effect is reduced. On F. solani, the studied nanomaterial only induced some texture and pigmentation changes. The microbicidal effect of chemically synthesized silver nanoparticles is greater in plant tissues than in culture media.

scholarly journals Insecticidal and Antifungal Activities of Chemically-Characterized Essential Oils from the Leaves of Withania frutescens L.

Life ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 88
Author(s):  
El Moussaoui Abdelfattah ◽  
Allali Aimad ◽  
Mohammed Bourhia ◽  
Khalid Chebbac ◽  
Ahmad Mohammad Salamatullah ◽  
...  
Keyword(s):  
Insecticidal Activity ◽  
Mycelial Growth ◽  
Callosobruchus Maculatus ◽  
Mortality Rates ◽  
Inhibitory Effect ◽  
Gas Chromatography Mass Spectrometry ◽  
Contact Toxicity ◽  
Inhalation Toxicity ◽  
Phytochemical Constituents ◽  
Significant Mortality

The current study was conducted to investigate antifungal and insecticidal activities of essential oil extracted from the Moroccan Withania frutescens L. (EOW), and their chemical composition was profiled. To achieve this goal, EOW was extracted by the hydro-distillation method and their phytochemical constituents were characterized by gas chromatography-mass spectrometry analyses (GC-MS). Insecticidal activity was evaluated by use of four tests: contact toxicity, inhalation toxicity, and repellent tests. Antifungal activity was evaluated on Fusarium oxysporum f. sp. Ciceris (F. oxysporum) using different concentrations of EOW. GC/MS analysis revealed that EOW was rich in carvacrol (31.87%), thymol (30.08%), and camphor (9.13%). At a 1-µL/L dose, EOW exhibited mortality rates of 23.13 ± 1.07% and 24.41 ± 1.21% against Callosobruchus maculatus (C.maculatus) by inhalation and contact, respectively. Notably, EOW dose of 20 μL/L caused significant mortality rates of 95.1 ± 3.5% and 76.69 ± 1.71% by inhalation and contact, respectively. EOW exhibited an inhibitory effect on mycelial growth against the tested fungi F. oxysporum of 100% and 93.5 ± 1.1% for the 9 and 4.5 mg/mL doses, respectively. The reduced mycelial growth rate for F. oxysporum was recorded to be 0.3 ± 0.1 and 0.6 ± 0.1 mm/h for the EOW doses of 2.25 and 4.5 mg/mL, respectively. The outcome of the present work showed that EOW has a promising antifungal and insecticidal activity, and it can therefore be employed as a natural alternative insecticidal and mycocidal agent to replace the chemically-synthesized ones.

scholarly journals Inhibitory effect of the glucosinolate–myrosinase system on Phytophthora cinnamomi and Pythium spiculum

2019 ◽  
Vol 55 (No. 2) ◽  
pp. 93-101 ◽  
Author(s):  
Francisco Teodoro Arroyo Cordero ◽  
Rocío Rodríguez-Arcos ◽  
Ana Jiménez-Araujo ◽  
Rafael Guillén-Bejarano ◽  
María José Basallote ◽  
...  
Keyword(s):  
Mycelial Growth ◽  
High Performance ◽  
Phytophthora Cinnamomi ◽  
Inhibitory Effect ◽  
Reversed Phase ◽  
Field Application ◽  
Additional Information ◽  
Array Detection ◽  
Important Additional Information

Glucosinolate extracts from sprouts of common Brassica nigra, B. juncea cv. Scala, B. carinata cv. Eleven, and Sinapis alba cv. Ludique were analysed by reversed phase high-performance liquid chromatography-diode array detection-mass spectrometry. The effect of the glucosinolate–myrosinase system on in vitro mycelial growth of Phytophthora cinnamomi Rands and Pythium spiculum B. Paul was assessed. Likewise, sinigrin and sinalbin monohydrate commercial standards were also tested. The extracts from B. carinata, which contained 159 mmol/g plant DW equivalent (85% sinigrin, 5% gluconapin, and 3% glucotropaeolin), were the most effective against Phytophthora and Pythium isolates used in this study. However, the extract from S. alba, which contained 1 180 mmol/g (100% sinalbin), did not inhibit the mycelial growth of the isolates tested. The use of the glucosinolate-myrosinase system provides important additional information to advance in the implementation of field application of brassicaceous amendments for the control of soil-borne pathogens.

scholarly journals Effect of photosensitisers on growth and morphology of Phytophthora citrophthora coupled with leaf bioassays in pear seedlings

2020 ◽  
Vol 56 (No. 2) ◽  
pp. 74-82 ◽  
Author(s):  
Antonios Zambounis ◽  
Oksana Sytar ◽  
Dimitris Valasiadis ◽  
Zoe Hilioti
Keyword(s):  
Mycelial Growth ◽  
Biological Effects ◽  
Dry Weight ◽  
Colony Growth ◽  
Inhibitory Effect ◽  
Economic Losses ◽  
Inhibitory Effects ◽  
Phytophthora Citrophthora ◽  
Irregular Shapes ◽  
Zoospore Production

The phytopathogenic oomycetes of the genus Phytophthora cause devastating economic losses worldwide.<br />Naphthodianthrone compounds, present in plant extracts of buckwheat and Saint John’s wort act as photosensitiser<br />agents and exhibit antimicrobial activity against a number of pathogens. In this study, we investigated the potential<br />inhibitory effects of fagopyrin and hypericin on Phytophthora citrophthora (R.E. Sm. &amp; E.H. Sm.) Leonian 1906, the<br />main causal agent of rot diseases in deciduous trees. Fagopyrin had the highest inhibitory effect in the colony growth<br />at a concentration of 2% of a stock solution (3 mg/mL), inducing clubbed hyphae with round tips. Notably, hypericin<br />also inhibited the radial colony growth and increased the hyphal branching at the subapical region, while also promoting<br />the formation of enlarged cells with irregular shapes growing collectively as biofilm-like structures. In terms of the<br />mycelial dry weight, although both photosensitisers had considerable inhibitory effects, the fagopyrin treatment was<br />most effective. Leaf bioassays showed that under dark conditions the photosensitiser pre-treated zoospores formed a<br />dense, but aberrant, mycelial growth with penetration defects. In contrast, when the zoospore production was performed<br />under light conditions, the zoospores failed to cause necrotic lesions and penetration events implying that their<br />virulence was impaired. These findings shed light on the biological effects of fagopyrin and hypericin in the regulation<br />of the mycelial growth, morphology and pathogenicity of P. citrophthora.

scholarly journals Microbial Decontamination of Onion by Corona Discharge Air Plasma during Cold Storage

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Eun Ha Chang ◽  
Yeoung Seuk Bae ◽  
Il Sheob Shin ◽  
Hyun Jin Choi ◽  
Ji Hyun Lee ◽  
...  
Keyword(s):  
Corona Discharge ◽  
Cold Storage ◽  
Mycelial Growth ◽  
Fungal Pathogens ◽  
Antimicrobial Agents ◽  
Treatment Time ◽  
Inhibitory Effect ◽  
Active Species ◽  
Conidial Germination ◽  
Air Plasma

Corona discharge air plasma (CDAP) is a nonthermal decontamination technology which is generating antimicrobial agents such as photons, electrons, positively and negatively charged ions, atoms, and free radicals. We investigated the effect of a corona discharge under atmospheric pressure on the sterilization of postharvest fungal pathogens on onion. The main antimicrobial reactive substance generated by CDAP was O3. The active species such as nitric oxide (NO) and nitric dioxide (NO2) were nearly detected in this experiment. CDAP treatment revealed different isolation frequencies depending on postharvest pathogens from diseased onions, showing less isolation frequency of Fusarium spp. and Alternaria sp. than that of Botrytis spp. when compared with untreatment onions during 10-month cold storage. CDAP treatment at 2∼2.6 ppm of O3 slightly stimulated the mycelial growth of Alternaria sp., while the treatment at 20∼24 ppm of O3 gradually inhibited mycelial growth by treatment time. However, Botrytis sp. showed different patterns of mycelial growth with CDAP treatment. Less than 4 hours’ treatment of CDAP slightly inhibited the mycelial growth of Botrytis sp., while 8 hours’ treatment of CDAP slightly stimulated the mycelial growth of Botrytis sp. not depending on the concentration of O3. The inhibitory effect of CDAP on the conidial germination of Alternaria sp. and Botrytis sp. was examined with treatment time and intensity of CDAP. The conidial germination of Alternaria sp. treated with CDAP at the concentration of 13.7∼14.4 ppm of O3 was strongly inhibited by time, showing y = 2.66x2 − 85.139x + 4.88 and R2 = 0.98. When the conidia of Alternaria sp. were exposed for 2 hours with varying plasma O3 concentration, the conidial germination was strongly inhibited as the concentration of O3 increases, showing y = −0.09x2 + 6.905x − 0.764 and R2 = 0.95. The conidia of Botrytis sp. also showed similar patterns to CDAP. The inhibitory effect of CDAP on the germination of postharvest pathogens depends on treatment time and O3 concentration.

scholarly journals Sensitivity of Colletotrichum gloeosporioides Isolates from Diseased Avocado Fruits to Selected Fungicides in Kenya

2018 ◽  
Vol 2018 ◽  
pp. 1-6
Author(s):  
Stanley Kirugo Kimaru ◽  
E. Monda ◽  
R. C. Cheruiyot ◽  
J. Mbaka ◽  
A. Alakonya
Keyword(s):  
Mycelial Growth ◽  
Colletotrichum Gloeosporioides ◽  
Field Tests ◽  
Inhibitory Effect ◽  
Copper Oxychloride ◽  
Randomized Design ◽  
Agroecological Zones ◽  
Completely Randomized Design ◽  
Growing Region

Colletotrichum gloeosporioides is a serious postharvest pathogen of avocado fruits worldwide. Kenya lacks any registered fungicides for the management of the disease. Nevertheless, farmers commonly use commercially available fungicides such as Bayleton 25WP (Triadimefon 250 g/Kg), Milraz 76WP (Propineb 70% and Cymoxanil 6%), and Copper oxychloride 500WP for disease management. The efficacy of these fungicides against C. gloeosporioides is not known. The purpose of this study was therefore to test the inhibitory effect of these fungicides against 46 C. gloeosporioides isolates from avocado fruits collected from varieties grown at different agroecological zones in Murang’a County, a popular avocado-growing region in Kenya. Mycelial growth rate and sporulation for each isolate were measured in vitro on PDA plates amended with different concentrations of the fungicides. Plates were arranged in a completely randomized design with three replications per treatment. All fungicides were effective in vitro but there were significant differences in sensitivity among isolates. Bayleton had the highest mycelial inhibition followed by Milraz, while copper oxychloride had the lowest mycelial inhibition rates, ranging from 81% to 88%. However, copper oxychloride was more effective in inhibiting sporulation. The inhibitory effect of each fungicide was concentration-dependent, where twice the recommended concentration had the highest inhibitory effect, followed by the recommended concentration. Our results show that the fungicides used by farmers against C. gloeosporioides, the causal agent for anthracnose, are effective. We, however, recommend further field tests in different avocado-growing areas so as to validate their efficacy against various isolates and under different environments.

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