Articles de revues : « Inhibitory effect on mycelial development »

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Lee, Hee-Kyung, On-you Choi, Hyun-suk Choi, Myung-ja Lee et Kwan-jong Yu. « 기능성차 개발을 위한 아위느타리 버섯 발효액 추출물의 아세틸콜린에스테라제 저해활성에 관한 연구 ». Association for International Tea Culture 58 (31 décembre 2022) : 135–59. http://dx.doi.org/10.21483/qwoaud.58..202212.135.

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This study was to investigate the inhibitory activity of oxidation and acetylcholinesterase using acetone, hexane, ethyl acetate, hot water and ethanol extracts of mycelia obtained from submerged culture from Pleurotus eryngii (DC. ex Fr.) Quel. var. ferulae Lanzi for function tea development. Among various solvent extracts on the oxidation inhibitory activity, the ethanol extract obtained 66.18% of the maximum inhibitory activity. In the case of acetylcholinesterase inhibitory activity, the hot water extract obtained 13.24% of the maximum inhibitory activity. The maximum inhibitory activity of acetylcholinesterase was obtained 17.36% at 40℃ of extract temperature. The maximum inhibitory activity of oxidation was obtained 63.28% at 60℃. The oxidation inhibitory activity was increased from 50.63 to 60.17% when extract time was increased from 2hr to 4hr at 60℃. On the other hand, in the case of over 6hr of extract time, it was decreased to 55.43% at 12hr of extract time. Thermal and pH of acetylcholinesterase inhibitor were stable at 10-30℃ and pH 5.0 to 9.0. As a result, it is considered that this pretreatment effect is effective in promoting inhibitory activity of acetylcholinesterase and oxidation using P. eryngii (DC. ex Fr.) Quel. var. ferulae Lanzi mycelia.

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Ye, Huochun, Qin Wang, Fadi Zhu, Gang Feng, Chao Yan et Jing Zhang. « Antifungal Activity of Alpha-Mangostin against Colletotrichum gloeosporioides In Vitro and In Vivo ». Molecules 25, n^o 22 (16 novembre 2020) : 5335. http://dx.doi.org/10.3390/molecules25225335.

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We investigated alpha-mangostin (α-mangostin, α-MG), a xanthone natural product extracted from the pericarp of mangosteen (Garcinia mangostana), for its antifungal activities and possible mechanism against Colletotrichum gloeosporioides, which causes mango anthracnose. The results demonstrated that α-MG had a relatively high in vitro inhibitory activity against C. gloeosporioides among 20 plant pathogenic fungi. The median effective concentration (EC50) values of α-MG against mycelial growth were nearly 10 times higher than those of spore germination inhibition for both strains of C. gloeosporioides, the carbendazim-sensitive (CBD-s) and carbendazim-resistant (CBD-r). The results suggested that α-MG exhibited a better inhibitory effect on spore germination than on the mycelial growth of C. gloeosporioides. Further investigation indicated that the protective effect could be superior to the therapeutic effect for mango leaves for scab development. The morphological observations of mycelium showed that α-MG caused the accumulation of dense bodies. Ultrastructural observation further revealed that α-MG caused a decrease in the quantity and shape of the swelling of mitochondria in the mycelium cells of C. gloeosporioides. In addition, bioassays disclosed that the inhibitory activity of α-MG on spore germination was reduced by adding exogenous adenosine triphosphate (ATP). These results suggested that the mode of action of α-MG could be involved in the destruction of mitochondrial energy metabolism. The current study supports α-MG as a natural antifungal agent in crop protection.

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Reis, Ana Carolina Botelho dos, et Júlia Ronzella Ottoni. « Antifungal activity of homeopathic medicines against the white mold causing agent Sclerotinia sclerotiorum ». Acta Scientiarum. Biological Sciences 43 (25 octobre 2021) : e56548. http://dx.doi.org/10.4025/actascibiolsci.v43i1.56548.

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White mold disease, caused by fungus Sclerotinia sclerotiorum (Lib.) de Bary., is a disease hard to control due to the high amount of sclerotia produced, which guarantees its survival in the soil for years leading to significant yield losses. Alternative techniques to control the pathogen have been researched, including homeopathy. The present work aimed to evaluate the in vitro antifungal effect of homeopathic medicines on S. sclerotiorum mycelial growth. Homeopathic medicines Sulphur, fungal sclerotium Nosode and Calcarea carbonica, in 30CH, 200CH and 1000CH dynamizations were tested. Assays were carried out in a completely randomized design, with four repetitions. Experiments were performed through the addition of homeopathic medicines on the surface of plates containing culture medium, followed by insertion of a disc containing fungus mycelia and incubation. Control treatment received no homeopathic medicine. The mycelial progression was monitored by seven halo diameter measurements during experiment period. All homeopathic medicines tested and their dynamizations were able to inhibit partially the development of the fungus. Calcarea carbonica at the dynamization of 1000 CH showed the best inhibitory effect on S. sclerotiorum, which under its effect produced a mycelial halo 40% smaller than the control treatment.

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Saniewska, Alicja. « Effect of polyamine biosynthesis inhibitors on in vitro growth of Phyllosticta antirrhini Sydow and on the infection of Antirrhinum majus L. by the pathogen ». Acta Agrobotanica 52, n^o 1-2 (2013) : 11–18. http://dx.doi.org/10.5586/aa.1999.002.

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Polyamine biosynthesis inhibitors, DL-α-difluromethylornithine (DFMO) and DL-α-difluromethylarginine (DFMA) at concentrations of 1,0 and 3,0 mM greatly inhibited mycelial growth of Phyllosticta antirrhini on Czapek Dox Agar (CDA). Putrescine at the concentration of 1,0 mM completely reversed the inhibitory effect of DFMO but only partially that of DFMA. Both polyamine biosynthesis inhibitors at concentrations 1,0 and 3,0 mM applied preventively and curatively strongly inhibited the development of the pathogen on snapdragon leaves.

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Wang, Yaochen, Keke Wei, Xiaobin Han, Donglin Zhao, Yanfen Zheng, Jianmin Chao, Jianyu Gou, Fanyu Kong et Cheng-Sheng Zhang. « The Antifungal Effect of Garlic Essential Oil on Phytophthora nicotianae and the Inhibitory Component Involved ». Biomolecules 9, n^o 10 (21 octobre 2019) : 632. http://dx.doi.org/10.3390/biom9100632.

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This study explored the chemical compositions of garlic essential oil, the inhibitory activity of garlic essential oil and diallyl disulfide (DADS) against Phytophthora nicotianae, and the effects on mycelial plasma membrane permeability and P. nicotianae inhibition. In total, 29 compounds were detected in garlic essential oil, of which 26 were detected by gas chromatography‒mass spectrometry (GC-MS) and 21 by headspace solid-phase microextraction (HS-SPME) GC-MS. DADS (60.12% and 19.09%) and trisulfide di-2-propenyl (14.18% and 17.98%) were the major components identified by HS-SPME GC-MS and GC-MS analysis, respectively. Half-inhibitory concentration (Ec50, antagonism) and minimum inhibitory concentration (MIC, fumigation) of DADS against P. nicotianae were 150.83 μL/L and 20 μL/L, respectively, while Ec50 of garlic essential oil was 1108.25 μL/L. Mycelial membrane permeability gradually increased in a concentration-dependent manner, and cell death increased at 450 μL/L DADS. Furthermore, DADS treatment significantly reduced the incidence of tobacco black shank and the number of P. nicotianae pathogens in rhizosphere soil. DADS also promoted root development of tobacco seedlings at low concentrations, which was inhibited at high concentrations. Therefore, DADS may play an important role in the antifungal effect against P. nicotianae by destroying mycelial cell membrane integrity, causing an increase in cell membrane permeability, and leading to cell death.

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Padgett, Merilark, et Janice C. Morrison. « Changes in Grape Berry Exudates during Fruit Development and Their Effect on Mycelial Growth of Botrytis cinerea ». Journal of the American Society for Horticultural Science 115, n^o 2 (mars 1990) : 269–73. http://dx.doi.org/10.21273/jashs.115.2.269.

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Grape berries (Vitis vinifera L., `Thompson Seedless') exuded a variety of compounds through the cuticle and epicuticular wax layer onto the berry surface. The composition of the exudate changed through the course of the growing season. Phenolic compounds and malic acid were in relatively high concentrations in grape berry exudates after bloom, but were low in exudates from mature fruit. The rate of decrease of phenols and malic acid was more rapid during the early stage of berry growth than during the ripening period. Sugar and potassium concentrations in the berry exudates were low at bloom, but increased rapidly in the later stages of ripening. Water extracts of berry exudates contained sugars, malic acid, potassium, and sodium. The water extracts promoted mycelial growth of Botrytis cinerea Pers. Ethanol and ether extracts contained phenols and lipids. These fractions from fruit sampled in the first 3 weeks after bloom strongly inhibited mycelial growth. The inhibitory effect of these fractions decreased later in the season.

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Mohammed, Sabah R., Elsayed M. Zeitar et Ivan D. Eskov. « Inhibition of Mycelial Growth of Rhizoctonia Solani by Chitosan in vitro and in vivo ». Open Agriculture Journal 13, n^o 1 (20 décembre 2019) : 156–61. http://dx.doi.org/10.2174/1874331501913010156.

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Objective: Evaluate the antifungal effect of chitosan against Rhizoctonia solani in vitro and the possible mechanisms of its induced activity in potato tubers to control black scurf disease. Methods: The in vitro influence of chitosan at different concentrations on mycelial growth of R. solani was tested by using the poisoned food technique in PDA medium. The effect of these concentrations on the development of lesion diameters in tubers inoculated with R. solani mycelium was assayed for 30 days. The concentration that showed the greatest inhibitory effect on lesion diameters was tested to assess the induced activity of defense-related enzymes in the infected tubers. Results: In the poisoned food technique, chitosan at 1% completely inhibited the growth of R. solani mycelium. In vivo tests showed that chitosan treatment at 0.5% effectively controlled the black scurf in tubers inoculated with R. solani mycelium. Chitosan increased the activities of defense-related enzymes such as Peroxidase (POD), Polyphenol Oxidase (PPO) and Phenylalanine Ammonia-lyase (PAL) in treated tubers of tested cultivars. Conclusion: This work demonstrated that chitosan directly inhibited the growth of R. solani, and potentially elicited defense reaction in potato tubers.

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Tian, Jun, Xiaobin Zeng, Hong Zeng, Zhaozhong Feng, Xiangmin Miao et Xue Peng. « Investigations on the Antifungal Effect of Nerol againstAspergillus flavusCausing Food Spoilage ». Scientific World Journal 2013 (2013) : 1–8. http://dx.doi.org/10.1155/2013/230795.

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The antifungal efficacy of nerol (NEL) has been proved againstAspergillus flavusby usingin vitroandin vivotests. The mycelial growth ofA. flavuswas completely inhibited at concentrations of 0.8 μL/mL and 0.1 μL/mL NEL in the air at contact and vapor conditions, respectively. The NEL also had an evident inhibitory effect on spore germination inA. flavusalong with NEL concentration as well as time-dependent kinetic inhibition. The NEL presented noticeable inhibition on dry mycelium weight and synthesis of aflatoxin B1(AFB1) byA. flavus, totally restraining AFB1production at 0.6 μL/mL. In real food system, the efficacy of the NEL on resistance to decay development in cherry tomatoes was investigatedin vivoby exposing inoculated and control fruit groups to NEL vapor at different concentration. NEL vapors at 0.1 μL/mL air concentration significantly reduced artificially contaminatedA. flavusand a broad spectrum of fungal microbiota. Results obtained from presented study showed that the NEL had a great antifungal activity and could be considered as a benefit and safe tool to control food spoilage.

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Adebayo, Oyeboade, André Bélanger et Shahrokh Khanizadeh. « Variable inhibitory activities of essential oils of three Monarda species on the growth of Botrytis cinerea ». Canadian Journal of Plant Science 93, n^o 6 (novembre 2013) : 987–95. http://dx.doi.org/10.4141/cjps2013-044.

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Adebayo, O., Bélanger, A. and Khanizadeh, S. 2013. Variable inhibitory activities of essential oils of three Monarda species on the growth of Botrytis cinerea . Can. J. Plant Sci. 93: 987–995. The antifungal effects of the essential oils of three Monarda species (Monarda didyma L., M. fistulosa L., and M. didyma var. 80-1A L.) were evaluated against Botrytis cinerea Pers.: Fr. The inhibitory effects of the volatile and contact phases of the essential oils were determined on hyphae and spores. The effects of the essential oils on the morphological structures of hyphae were studied under light microscopy. All the three tested essential oils types had inhibitory effects on both mycelia and spores as follows, in descending order of effectiveness: M. didyma > M. didyma var. 80-1A > M. fistulosa. For all essential oils, the volatile phase effects were more toxic on fungal growth than the contact phase effects. All the essential oils in the contact studies achieved complete inhibition of mycelial growth and spore germination at 819.2 µg mL−1 of ethanol and Tween 20 mixture. In the volatile studies, however, complete mycelial inhibition was achieved with M. didyma and M. didyma var. 80-1A at 0.1 µg mL−1 air and with M. fistulosa at 0.2 µg mL−1 air. Spore germination was inhibited at 0.05 µg mL−1 air with M. didyma and 0.2 µg mL−1 air with both M. didyma var. 80-1A and M. fistulosa. This study demonstrated that these essential oils are promising potential antifungal agents that could be used in the development of biofungicide alternatives to synthetic fungicides against B. cinerea.

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Laugale, Valda, Līga Jankevica, Ineta Samsone, Jūlija Haļimona, Rita Sešķēna, Zane Metla, Jānis Lepsis, Regina Rancane et Māris Daugavietis. « Preliminary Studies on Development of a New Environmentally Friendly Plant Protection Product Against Grey Mould ». Proceedings of the Latvian Academy of Sciences. Section B. Natural, Exact, and Applied Sciences 67, n^o 2 (1 août 2013) : 199–202. http://dx.doi.org/10.2478/prolas-2013-0033.

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The development of new environmentally friendly plant protection products against grey mould disease (caused by Botrytis cinerea Pers.) was started in 2010. In the Latvian State Forest Research Institute “Silava”, production of coniferous biomass extracts using different solvents for extraction was performed. During 2010-2011, several laboratory investigations were carried out in the Institute of Biology, University of Latvia. Effectiveness of pine (Pinus sylvestris) and spruce (Picea abies) biomass extracts against Botrytis cinerea was tested. On the basis of coniferous extracts, 11 formulations were created and characterised. The effect of the formulations on mycelial growth of B. cinerea test cultures was tested using the fungal radial growth test. All formulations had inhibitory effect on mycelium growth (inhibition rate over 50%) at concentration 20 g L-1 in medium. The impact of formulations on plants after spraying was evaluated using in vitro propagated strawberry plants. Chlorophyll content and chlorophyll fluorescence were estimated. Extracts did not show negative effect on the chlorophyll content and fluorescence of strawberry leaves. Field investigations on strawberry (Fragaria × ananassa Duch.) ‘Senga Sengana’ and primocane raspberry (Rubus idaeus) ‘Gerakl’ were conducted in the Pûre Horticultural Research Centre in 2011. None of tested the coniferous biomass extract formulations showed higher effectiveness than fungicide Signum® (pyraclostrobin 6.7%+ boscalid 26.7%, BASF).

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Gao, Y. Y., X. X. Li, L. F. He, B. X. Li, W. Mu et F. Liu. « Effect of Pyrisoxazole on Colletotrichum scovillei Infection and Anthracnose on Chili ». Plant Disease 104, n^o 2 (février 2020) : 551–59. http://dx.doi.org/10.1094/pdis-06-19-1291-re.

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Anthracnose caused by Colletotrichum scovillei is one of the most destructive diseases affecting chili production. Disease control mainly relies on conventional fungicides, and repeated exposure to single-site mode-of-action fungicides may pose a risk for the development of resistant isolates within the population. Our previous study suggested that pyrisoxazole has strong inhibitory activity against C. scovillei in vitro. However, the effects of pyrisoxazole on the C. scovillei infection process and the performance of pyrisoxazole in the field remain unclear. In this study, pyrisoxazole exhibited strong inhibitory activity against the mycelial growth, appressorium formation, and appressorium diameter of C. scovillei, with half maximal effective concentration values of 0.1986, 0.0147, and 0.0269 μg/ml, respectively, but had no effect on sporulation, even at the highest concentration of 1.6 μg/ml. The baseline sensitivity curves were unimodal with a long right-hand tail. The in vivo data showed that pyrisoxazole provided both preventive and curative activity against anthracnose on chili. Pyrisoxazole decreased the incidence of anthracnose and reduced disease progress. The results of electron microscopy showed that pyrisoxazole can affect the C. scovillei infection process by altering mycelial morphology, degrading conidia and germ tubes, suppressing conidial germination and appressorium formation, and enhancing conidiophore production. Pyrisoxazole can be used to effectively control anthracnose under field conditions and increase chili yield; moreover, no phytotoxicity symptoms were observed after treatment. These results provide new insight into the mechanisms by which pyrisoxazole controls disease and suggest that pyrisoxazole is a feasible alternative for the management of anthracnose in chili.

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Bomar, M. T., et M. Bomar. « Assay of the inhibitory effect of pentachlorophenol and formaldehyde on mycelial growth and development of reproductive structures inAspergillus niger ». Folia Microbiologica 44, n^o 5 (octobre 1999) : 519–22. http://dx.doi.org/10.1007/bf02816253.

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Chen, Yun-Ze, Shu-Ren Wang, Tao Li, Guo-Cai Zhang et Jing Yang. « Antifungal Activity of 6-Methylcoumarin against Valsa mali and Its Possible Mechanism of Action ». Journal of Fungi 9, n^o 1 (20 décembre 2022) : 5. http://dx.doi.org/10.3390/jof9010005.

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Valsa canker of apple (VCA) caused by Valsa mali severely affected apple production in east Asia. With the increase in drug resistance, there is an urgent need for efficient and environmentally friendly antifungal agents. Coumarins have attracted much attention due to their excellent antimicrobial activity against plant pathogens. In this study, the antifungal activity of several coumarins against phytopathogenic fungi was evaluated, and then the antifungal activity of the screened 6-MCM against V. mali and its underlying mechanism was further investigated. The results of the in vitro antifungal activity assay showed that some coumarins had significant inhibitory effects on V. mali. Notably, 400 mg/L of 6-MCM had the best antifungal activity of 94.6%. Further experiments showed that 6-MCM slowed down the growth of V. mali mycelia and the germination of spores in a concentration-dependent manner, with EC50 of 185.49 and 54.62 mg/L, respectively. In addition, 6-MCM treatment increased mycelial conductivity, extracellular protein leakage, and MDA content, resulting in damage to the cell membrane. Moreover, 6-MCM significantly reduced the cell wall degrading enzymes secreted by V. mali, including EG, PG and PL, thereby limiting its pathogenic capacity. SEM and TEM results showed that 6-MCM treatment had a significant effect on the morphology and ultrastructure of mycelial cells. Inoculation of isolated apple branches found that the application of 6-MCM effectively inhibited the development of VCA and significantly reduced the incidence. All these results suggest that 6-MCM has the potential as a green substitute for VCA control.

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Tkaczyk, Miłosz, Artur Pacia, Marta Siebyła et Tomasz Oszako. « Phosphite fertilisers as inhibitors of Hymenoscyphus fraxineus (anamorph Chalara fraxinea) growth in tests in vitro ». Folia Forestalia Polonica 59, n^o 1 (1 mars 2017) : 79–81. http://dx.doi.org/10.1515/ffp-2017-0008.

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Abstract This study is designed to test the potential for reducing the growth of the mycelium of the fungus Hymenoscyphus fraxineus (anamorph Chalara fraxinea) by using phosphite preparations at various concentrations in vitro. The study shows that adding pure phosphite to potato dextrose agar media inhibits the development of the fungus, but if the preparation is applied in the form of ammonium phosphite (Actifos), the growth of fungus will be accelerated. Probably the addition of nitrogen contained in the product Actifos has positive effect on the mycelial growth, but pure phosphite restricts its development. These studies are preliminary and only show the potential use of phosphite to reduce the development of H. fraxineus; however, to completely confirm its operation, further research is needed in this area.

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Mukhametova, Gulnaz M., Eugeny G. Vinokurov, Elena S. Babusenko et Vladimir D. Skopintsev. « BIODEGRADATION OF SOLUTIONS FOR CHEMICAL NICKELATION ». IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 61, n^o 9-10 (22 octobre 2018) : 89–97. http://dx.doi.org/10.6060/ivkkt.20186109-10.5792.

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In this article, we examined the susceptibility of biodegradation of nickel-containing processing solutions and selected fungicidal products which meet the requirements. Technological solutions are characterized by such a priority parameter as the high deposition rate of the nickel coating were subject to biofouling by mycelial fungi, despite the presence of heavy metal ions in solutions. It is established that the development of mycelial fungi in solutions leads to their decomposition and deterioration of technological characteristics. The purpose of the study was to select the fungicide and its corresponding concentrations, which do not adversely affect the process rate and the quality of the coating. The following tasks were posed: investigation of the stability of various solutions for nickel plating to the action of microorganisms; identification of taxonomic affiliation of microorganisms that populate solutions; selection of fungicide, meeting the requirements for neutrality to the components of the solution, as there is no effect on the rate of the process. Based on the results of the experiment, the influence of microorganisms on the technological characteristics of solutions was determined. After the appearance and development of the colonies of mycelial fungi in time solutions, the pH changed to an alkaline region, the deposition rate of the Ni-P coating dropped. Copper sulfate, sodium tetraborate, lactic acid, chloroform was used as inhibitors. The use of copper sulfate fungicide in concentrations of 0.002-0.005 mol/l led to the inhibition of growth of the fungal colonies, but insignificant. Fungicide sodium tetraborate at a concentration of 0.03 mol/l had a noticeable inhibitory effect on the growth of fungi, and also had a positive effect on the rate of the process, which meets all the requirements for this compound. For citation: Mukhametova G.M., Vinokurov E.G., Babusenko E.S., Skopintsev V.D. Biodegradation of solutions for chemical nickelation. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 9-10. P. 89-97

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Tahiri, Nor EL Houda, Hamza Saghrouchni, Noureddine Hamamouch, Mostafa El Khomsi, Abdulhakeem Alzahrani, Ahmad Mohammad Salamatullah, Lyoussi Badiaa et Lalla Aicha Lrhorfi. « Treatment with Glyphosate Induces Tolerance of Citrus Pathogens to Glyphosate and Fungicides but Not to 1,8-Cineole ». Molecules 27, n^o 23 (28 novembre 2022) : 8300. http://dx.doi.org/10.3390/molecules27238300.

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During the postharvest period, citrus fruits are exposed to Penicillium italicum, Penicillium digitatum, and Geotrichum candidum. Pesticides such as imazalil (IMZ), thiabendazole (TBZ), orthophenylphenol (OPP), and guazatine (GUA) are commonly used as antifungals. Glyphosate (GP) is also used in citrus fields to eliminate weed growth. The sensitivity of fungal pathogens of citrus fruit to these pesticides and 1,8-cineole was evaluated, and the effect of GP on the development of cross-resistance to other chemicals was monitored over a period of 3 weeks. IMZ most effectively inhibited the mycelial growth and spore germination of P. digitatum and P. italicum, with minimum inhibitory concentrations (MICs) of 0.01 and 0.05 mg/mL, respectively, followed by 1,8-cineole, GP, and TBZ. 1,8-Cineole and GP more effectively inhibited the mycelial growth and spore germination of G. candidum, with minimum inhibitory concentrations (MICs) of 0.2 and 1.0 mg/mL, respectively, than OPP or GUA. For the spore germination assay, all substances tested showed a total inhibitory effect. Subculturing the fungal strains in culture media containing increasing concentrations of GP induced fungal tolerance to GP as well as to the fungicides. In soil, experiments confirmed that GP induced the tolerance of P. digitatum to TBZ and GP and the tolerance of P. italicum to IMZ, TBZ, and GP. However, no tolerance was recorded against 1,8-cineole. In conclusion, it can be said that 1,8-cineole may be recommended as an alternative to conventional fungicides. In addition, these results indicate that caution should be taken when using GP in citrus fields.

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Duarte, Sónia, Ana Magro, Joanna Tomás, Carolina Hilário, Ricardo Boavida Ferreira et Maria Otília Carvalho. « Antifungal Activity of Benzoquinones Produced by Tribolium castaneum in Maize-Associated Fungi ». Insects 13, n^o 10 (24 septembre 2022) : 868. http://dx.doi.org/10.3390/insects13100868.

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Tribolium castaneum (Herbst) adults produce 1,4-benzoquinone (BQ), methyl-1,4-benzoquinone (MBQ), and ethyl-1,4-benzoquinone (EBQ). These components are chemical defenses used as repellents and irritants, and BQ has a negative impact on the growth of some fungal species. In this work, the inhibitory and/or lethal effects of these benzoquinones on the development of six fungi identified in maize, namely Aspergillus flavus, A. fumigatus, A. niger, Fusarium sp., Penicillium sp., and Trichoderma sp., were evaluated. Ten-day-long disk diffusion trials were performed using benzoquinones. The experiments simulated the activity of BQ (B1) or “EBQ + MBQ” (B2) released by 40-day-old insect adults (n = 200), considering a total average release of 45 µg per adult. Inhibition halos imposed by benzoquinones on fungal growth showed a significant effect when compared with the controls (water and solvent). Mycelial growth was decreased for all fungi, with the level of response depending on the fungal species. B1 and B2 displayed an inhibitory effect against all fungi, but Trichoderma sp. and A. niger showed rapid recoveries. B2 showed a lethal effect on Penicillium sp. The inhibitory and lethal activities of benzoquinones released by T. castaneum adults may contribute to regulate fungal growth, and understanding their interaction is important to develop innovative control strategies.

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Hpoo, May Khaing, Maryia Mishyna, Valery Prokhorov, Tsutomu Arie, Akihito Takano, Yosei Oikawa et Yoshiharu Fujii. « Potential of Octanol and Octanal from Heracleum sosnowskyi Fruits for the Control of Fusarium oxysporum f. sp. lycopersici ». Sustainability 12, n^o 22 (10 novembre 2020) : 9334. http://dx.doi.org/10.3390/su12229334.

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The antifungal activity of volatile compounds from the fruit, leaf, rhizome and root of 109 plant species was evaluated against Fusarium oxysporum f. sp. lycopersici (FOL) race 1—the tomato wilt pathogen—by using the modified dish pack method. Eighty-eight plant samples inhibited mycelial growth, including volatiles from fruits of Heracleum sosnowskyi, which exhibited the strongest antifungal activity, showing 67% inhibition. Two volatile compounds from the fruits of H. sosnowskyi (octanol and octanal) and trans-2-hexenal as a control were tested for their antifungal activities against FOL race 1 and race 2. In terms of half-maximal effective concentration (EC50) values, octanol was found to be the most inhibitory compound for both pathogenic races, with the smallest EC50 values of 8.1 and 9.3 ng/mL for race 1 and race 2, respectively. In the biofumigation experiment, the lowest disease severity of tomato plants and smallest conidial population of race 1 and race 2 were found in trans-2-hexenal and octanol treated soil, while octanal had an inhibitory effect only on race 2. Therefore, our study demonstrated the effectiveness of volatile octanol and trans-2-hexenal on the control of the mycelial growth of two races of Fusarium oxysporum f. sp. lycopersici and may have potential for the future development of novel biofumigants.

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Shi, W. Q., L. B. Xiang, D. Z. Yu, S. J. Gong et L. J. Yang. « Impact of the biofungicide tetramycin on the development of Fusarium head blight, grain yield and deoxynivalenol accumulation in wheat ». World Mycotoxin Journal 13, n^o 2 (6 mars 2020) : 235–46. http://dx.doi.org/10.3920/wmj2019.2494.

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Fusarium graminearum causes Fusarium head blight (FHB), a devastating disease that leads to extensive yield and quality loss in wheat and barley production. Integrated pest management (IPM) is required to control this disease and biofungicides, such as tetramycin, could be a novel addition to IPM strategies. The current study investigated in vitro tetramycin toxicity in Fusarium graminearum and evaluated its effectiveness for the control of Fusarium head blight FHB. Tetramycin was shown to affect three key aspects of Fusarium pathogenicity: spore germination, mycelium growth and deoxynivalenol (DON) production. The in vitro results indicated that tetramycin had strong inhibitory activity on the mycelial growth and spore germination. Field trials indicated that tetramycin treatment resulted in a significant reduction in both the FHB disease index and the level of DON accumulation. The reduced DON content in harvested grain was correlated with the amount of Tri5 mRNA determined by qRT-PCR. Synergistic effects between tetramycin and metconazole, in both the in vitro and field experiments were found. Tetramycin could provide an alternative option to control FHB.

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El-Mougy, Nehal. « Effect of Some Essential Oils for Limiting Early Blight (Alternaria Solani) Development in Potato Field ». Journal of Plant Protection Research 49, n^o 1 (1 mars 2009) : 57–62. http://dx.doi.org/10.2478/v10045-009-0008-2.

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Effect of Some Essential Oils for Limiting Early Blight (Alternaria Solani) Development in Potato FieldThe fungicidal effect of some essential oils againstAlternaria solanione of the species that cause early blight of potato was evaluated underin vitroand field conditions. Effect of carnation, caraway, thyme oils and the chemical fungicide Ridomil MZ 72 at various concentrations on mycelial growth ofA. solaniwas tested. Carnation oil had the strongest and most extensive inhibitory effect on fungal growth. Slightly less effective were caraway and thyme oils followed by the chemical fungicide. Extended field trails for two cultivation seasons proved that the application of essential oils twice as foliar spray had a superior effect to the fungicide treatment for reducing the early blight incidence comparing with untreated control. An opposite relationship between the disease incidence and concentrations of applied essential oils was observed. The increase in potato yield also followed the same trend. The highest reduction in disease incidence and yield increase was recorded in treatments with 1% of carnation, caraway and thyme oils in descending order. Ridomil MZ 72 applied at the dose recommended by manufactories had a low effect in this regard. Essential oils treatments might be used as easily applied, safe and cost effective control methods against such plant diseases.

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Liu, Yi-Tsz, Meng-Hwan Lee, Yin-Shen Lin et Wen-Lin Lai. « The Inhibitory Activity of Citral against Malassezia furfur ». Processes 10, n^o 5 (19 avril 2022) : 802. http://dx.doi.org/10.3390/pr10050802.

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The lipophilic yeast Malassezia furfur, is a member of the cutaneous commensal microbiota and is associated with several chronic diseases such as dandruff, pityriasis versicolor, folliculitis, and seborrheic dermatitis, that are often difficult to treat with current therapies. The development of alternatively effective antifungal therapies is therefore of paramount importance. In this study, we investigated the treatment effect of citral on M. furfur. The minimal inhibitory concentration of citral for M. furfur was 200 μg/mL, and the minimal fungicidal concentration was 300 μg/mL. Citral significantly increased the proportion of yeast cells to mycelial forms 2.6-fold. Phosphatidylserine externalization, DNA fragmentation, and metacaspase activation supported a citral-induced apoptosis in M. furfur. Moreover, citral at sub-minimum inhibitory concentrations reduced the invasion of M. furfur in HaCaT keratinocytes. Finally, we demonstrated that citral inhibited IL-6 and TLR-2 expression and enhanced HBD-2 and TSLP expression in M. furfur-infected HaCaT keratinocytes. These results showed that citral has antifungal activity at high concentrations and can decrease the infection of M. furfur by modulating the keratinocyte immune responses at low concentrations. Our results suggest that citral is a potential candidate for topical therapeutic application for M. furfur-associated human skin diseases.

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Zhang, Miao, Yongcai Li, Yang Bi, Tiaolan Wang, Yupeng Dong, Qian Yang et Tingting Zhang. « 2-Phenylethyl Isothiocyanate Exerts Antifungal Activity against Alternaria alternata by Affecting Membrane Integrity and Mycotoxin Production ». Toxins 12, n^o 2 (15 février 2020) : 124. http://dx.doi.org/10.3390/toxins12020124.

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Black spot caused by Alternaria alternata is one of the important diseases of pear fruit during storage. Isothiocyanates are known as being strong antifungal compounds in vitro against different fungi. The aim of this study was to assess the antifungal effects of the volatile compound 2-phenylethyl isothiocyanate (2-PEITC) against A. alternata in vitro and in pear fruit, and to explore the underlying inhibitory mechanisms. The in vitro results showed that 2-PEITC significantly inhibited spore germination and mycelial growth of A. alternata—the inhibitory effects showed a dose-dependent pattern and the minimum inhibitory concentration (MIC) was 1.22 mM. The development of black spot rot on the pear fruit inoculated with A. alternata was also significantly decreased by 2-PEITC fumigation. At 1.22 mM concentration, the lesion diameter was only 39% of that in the control fruit at 7 days after inoculation. Further results of the leakage of electrolyte, increase of intracellular OD260, and propidium iodide (PI) staining proved that 2-PEITC broke cell membrane permeability of A. alternata. Moreover, 2-PEITC treatment significantly decreased alternariol (AOH), alternariolmonomethyl ether (AME), altenuene (ALT), and tentoxin (TEN) contents of A. alternata. Taken together, these data suggest that the mechanisms underlying the antifungal effect of 2-PEITC against A. alternata might be via reduction in toxin content and breakdown of cell membrane integrity.

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Dou, Tao, Yubiao Cai, Xuhong Song, Futao Gao, Yajun Zhao, Jiafang Du, Fengqing Wang et al. « Characterization and Fungicide Screening of a New Pathogen That Causes Leaf Spot on Rehmannia glutinosa ». Agriculture 13, n^o 2 (26 janvier 2023) : 301. http://dx.doi.org/10.3390/agriculture13020301.

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Outbreaks of leaf spot disease occurred in Rehmannia glutinosa fields in Henan Province, China, in 2019, with the incidence ranging from 20% to 40%. R. glutinosa plants with diseased leaves were collected, and 25 isolates were obtained. Pathogenicity tests, morphological observations, and phylogenetic analyses were conducted to identify the pathogens, and the biological characteristics and control agents of the pathogens were studied. Five isolates of pathogenic fungi were isolated. Three isolates were identified as Fusarium equiseti, which is a new pathogen causing R. glutinosa leaf disease; the other two isolates were identified as Fusarium acuminatum. The mycelia of F. equiseti grew fastest on Czapek medium, and the optimal temperature and pH were 25 °C and 10.0, respectively. The mycelia of F. equiseti grew from 5 °C t o 35 °C, and the lethal temperature was 55 °C. The optimal carbon and nitrogen sources were soluble starch and peptone, respectively. Eight fungicides had inhibitory effects on the mycelial growth of F. equiseti and F. acuminatum. Prochloraz had higher activities against F. equiseti and F. acuminatum, with EC50 values of 0.139 mg·L−1 and 0.123 mg·L−1, respectively. These results provide useful information that will aid the development of management strategies to control leaf diseases of R. glutinosa caused by F. equiseti and F. acuminatum.

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Ouimet, A., O. Carisse et P. Neumann. « Evaluation of fungal isolates for the inhibition of vegetative growth of Venturis inaequalis ». Canadian Journal of Botany 75, n^o 4 (1 avril 1997) : 626–31. http://dx.doi.org/10.1139/b97-070.

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As a part of a broader study on biological control of apple scab, caused by Venturia inaequalis, a collection of 183 microorganisms originating from apple leaf litter was evaluated for their inhibitory effects on the vegetative growth of V. inaequalis. In a first screening, based on dual culture, 31 isolates (17%) showed inhibition. From these isolates, 11 fungi were selected for quantitative evaluation based on the presence of a distinct zone of inhibition. The selected fungi were evaluated again, in a more precise test, which indicated that isolates P164A (Ophiostoma sp.), P66A (Chaetophoma sp.), P26A (Aureobasidium sp.), P59A (Phoma sp.), and P28A (unidentified) inhibited 95.3, 88.9, 85.8, 80.7, and 80.1% of mycelial growth, respectively. Inhibition by the most effective fungus (Ophiostoma sp.) lasted for more than 58 days. A test using culture filtrates, incubated over time, was carried out to determine whether the living fungus was a prerequisite for inhibition. The inhibitory effect of metabolites secreted by the selected fungi was less than 5%. This study revealed the potential of at least five fungi that could be considered in the development of a biological control agent against V. inaequalis. Key words: antifungal inhibition, apple scab, biological control.

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Regeda, L., N. Bisko et G. Al-Maali. « Influence of Pholiota spp. (Strophariaceae, Basidiomycote) mycelial biomass on seed germination and seedlings growth of Lepidum sativum L. and Cucumis sativus L. » Bulletin of Taras Shevchenko National University of Kyiv. Series : Biology 84, n^o 1 (2021) : 53–60. http://dx.doi.org/10.17721/1728_2748.2021.84.53-60.

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Basidiomycetes represent a very diverse group of eukaryotic organisms in terms physiological parameters. Some organisms such as plants or fungi release certain secondary metabolites, which can affect the organisms around them. Some of the substances released by mushrooms could have effects on the growth and further development of nearby plants. Studies of fungi and their biologically active components have grown significantly, with the aim of potential introduction to various biotechnological processes.The allelopathic effect of Pholiota species has been investigated in this study. Mycelial biomass of seven screened Pholiota species were tested to study cucumber (Cucumis sativus L.) and lettuce (Lepidium sativum L.) seed germination and the sprouting growth. The results of our experiment showed that the biomass of the species of the genus Pholiota did not affect the germination of seeds of both plant species. 100% seed germination was recorded in both control and experimental samples. The addition of mycelial biomass of the Pholiota species led to a suppressive allelopathic effect, which affects seed germination, the length of the studied plant (both shoots and roots), as well as changes the morphology of the roots (pubescence, changes in lateral roots). The inhibitory effect on sprouting length was 8,6%-87,1% in the case of C. sativus and 42,2%-91,8% if specify for L. sativum in depence on Pholiota species. Allelopathic properties of Pholiota subochracea, where sprouting growth ratio did not exceed 12.9%, compared to the control group, should be noted. This result suggests that Pholiota mushrooms have a significant regulatory effect on lettuce and cucumber sprouting growth. The given results suggest that the studied species may play a significant role in relationships within ecosystems.

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Mayfield III, Albert, Edward Barnard, Jason Smith, Shawn Bernick, Jeffrey Eickwort et Tyler Dreaden. « Effect of Propiconazole on Laurel Wilt Disease Development in Redbay Trees and on the Pathogen In Vitro ». Arboriculture & ; Urban Forestry 34, n^o 5 (1 septembre 2008) : 317–24. http://dx.doi.org/10.48044/jauf.2008.043.

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Laurel wilt is a vascular disease of Lauraceous plants caused by a fungus (Raffaelea spp.) that is vectored by a recently introduced, nonnative ambrosia beetle (Xyleborus glabratus). The disease is devastating to redbay (Persea borbonia) trees in forests, parks, and residential landscapes in the southeastern United States, and management strategies for reducing its impact are needed. In this study, the systemic fungicide propiconazole completely inhibited mycelial growth of Raffaelea spp. in vitro at concentrations 0.1 parts per million (ppm) or greater and was fungitoxic at 1 ppm or greater, whereas the fungicide thiabendazole was less inhibitory. None of the ten mature redbay trees that received root-flare injections of propiconazole developed crown wilt symptoms for at least 30 weeks after being inoculated with Raffaelea spp., whereas nine of ten untreated control trees wilted in more than one-third of their crowns. Propiconazole was retained in the stem xylem for at least 7.5 months after injection but was more frequently detected in samples from trees injected 4.5 months earlier and was not well detected in small-diameter branches. Results suggest that propiconazole may be useful in preventing laurel wilt in redbay, but limitations and questions regarding duration of efficacy, rate of uptake, and efficacy under different levels of disease pressure remain.

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Husiatynska, Nataliia, Svitlana Teterina, Nataliia Hryhorenko et Olha Kalenik. « Study of the efficiency of the inhibitory effect of antimicrobial preparations in the production of sugar substances ». EUREKA : Life Sciences, n^o 4 (30 juillet 2021) : 43–49. http://dx.doi.org/10.21303/2504-5695.2021.001982.

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This article presents the relevance of the issue of inhibition of microbiological processes at different stages of processing of sugar-containing raw materials, in particular ensuring the microbiological purity of juices and syrups in the production of sugar substances. Information on the composition of microbiota contaminating raw materials in the production of beet sugar, raw cane sugar, food syrups from sugar sorghum is analyzed. Experimental data on the evaluation of the effectiveness of a number of antimicrobial preparations in terms of growth retardation of pure cultures of microorganisms and the effect of disinfection during the introduction of preparations are presented. The greatest danger in production is caused by the development of spore-forming and mucus-forming bacteria, which led to the choice of research objects. Thus, the effect of antimicrobial preparations on microorganisms: mesophilic bacteria Bacillus subtilis, B. megatherium, thermophilic bacteria B. stearothermophilus, mucus-forming bacteria of the genus Leuconostos, was investigated. In addition, the effect of antimicrobials on mycelial fungi of the genus Aspergillus was studied. Based on the conducted experimental studies, the range of costs of the studied antimicrobial preparation for the suppression of contaminating microflora in the production of sugar and food syrups from vegetable raw materials was determined

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Moore-Landecker, Elizabeth. « Response of Pyronema domesticum to volatiles from microbes, seeds, and natural substrata ». Canadian Journal of Botany 66, n^o 1 (1 janvier 1988) : 194–98. http://dx.doi.org/10.1139/b88-031.

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Volatiles emanating from fungi, bacteria, germinating or killed seeds, and nonsterile or sterile natural substrates (decaying wood, partially decayed oak duff, and garden soil) were tested for their effects on Pyronema domesticum, a pyrophilous discomycete. Mycelial growth was strongly stimulated by volatiles from Schizophyllum commune and inhibited by volatiles from Streptomyces griseus but otherwise was generally unaffected. Volatiles from Chaetomium globosum, a second Pyronema domesticum culture, Trichophea abundans, or Trichoderma viride had little or no effect on numbers of apothecia produced. Fewer apothecia formed with volatiles from Bacillus subtilis, Cyathus stercoreus, Dipodascopsis uninucleatus, Poronia aedipus, Proteus vulgaris, Micrococcus luteus, and Streptomyces griseus. Volatiles from all bacteria and Dipodascopsis uninucleatus impaired development of the ascogenous system. Elongated asci without ascospores formed in the presence of Proteus vulgaris. Apothecia did not form in the presence of volatiles from Sordaria fimicola, Schizophyllum commune, Rhizopus nigricans, germinating seeds, nonsterile wood, or charred duff. Volatiles from autoclaved seeds, nonsterile or autoclaved soil or duff, wood ashes, and sterile wood are strongly inhibitory for apothecial development and permitted only a few apothecia to form.

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Yang, Mingguan, Laifeng Lu, Shuhua Li, Jing Zhang, Zhenjing Li, Shufen Wu, Qingbin Guo, Huanhuan Liu et Changlu Wang. « Transcriptomic Insights into Benzenamine Effects on the Development, Aflatoxin Biosynthesis, and Virulence of Aspergillus flavus ». Toxins 11, n^o 2 (27 janvier 2019) : 70. http://dx.doi.org/10.3390/toxins11020070.

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Aspergillus flavus is a soilborne pathogenic fungus that poses a serious public health threat due to it contamination of food with carcinogenic aflatoxins. Our previous studies have demonstrated that benzenamine displayed strong inhibitory effects on the mycelial growth of A. flavus. In this study, we systematically investigated the inhibitory effects of benzenamine on the development, aflatoxin biosynthesis, and virulence in A. flavus, as well as the underlying mechanism. The results indicated that benzenamine exhibited great capacity to combat A. flavus at a concentration of 100 µL/L, leading to significantly decreased aflatoxin accumulation and colonization capacity in maize. The transcriptional profile revealed that 3589 genes show altered mRNA levels in the A. flavus after treatment with benzenamine, including 1890 down-regulated and 1699 up-regulated genes. Most of the differentially expressed genes participated in the biosynthesis and metabolism of amino acid, purine metabolism, and protein processing in endoplasmic reticulum. Additionally, the results brought us to a suggestion that benzenamine affects the development, aflatoxin biosynthesis, and pathogenicity of A. flavus via down-regulating related genes by depressing the expression of the global regulatory factor leaA. Overall, this study indicates that benzenamine have tremendous potential to act as a fumigant against pathogenic A. flavus. Furthermore, this work offers valuable information regarding the underlying antifungal mechanism of benzenamine against A. flavus at the level of transcription, and these potential targets may be conducive in developing new strategies for preventing aflatoxin contamination.

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Mejdoub-Trabelsi, Boutheina, Rania Aydi-Ben Abdallah, Hayfa Jabnoun-Khiareddine, Ayed Faker et Mejda Daami-Remadi. « Antagonizing Impact of Endophytic Fungal Isolates against Potato Black Scurf (Rhizoctonia solani) ». International Journal of Phytopathology 11, n^o 1 (30 avril 2022) : 09–18. http://dx.doi.org/10.33687/phytopath.011.01.3897.

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Four endophytic fungal isolates, naturally associated with Solanum tuberosum L., were evaluated for their antagonistic activity against Rhizoctonia solani and their ability to suppress black scurf disease of potato tubers. To identify the potential implication of antifungal compounds in their inhibitory activity, cell-free culture filtrates were produced and tested for their antifungal potential against R. solani mycelial growth and for their protective effect against development of on potato tuber slices. Results showed that percent inhibition of R. solani mycelial growth, based on in vitro antibiosis tests, ranged between 16 to 59%. Hyphal damage and lysis were the most frequent stress responses exhibited by the target pathogen during its in vitro interactions with the potato-associated fungi tested. All Cell-free culture filtrates of tested fungi had significantly inhibited the radial growth of Rhizoctonia solani Rs20. The cell-free culture filtrates of Penicillium chrysogenum and Aspergillus niger had decreased pathogen growth by more than 60% over control. These two filtrates (P. chrysogenum and A. niger) were found to be the most effective in decreasing the decay incidence in potato slices by 36 and 40%, respectively, as compared to pathogen-inoculated and untreated control. Thus, the present study clearly demonstrated that fungal isolates, occurring ubiquitously within potato plants, may be explored as potent biocontrol agents against potato-associated fungal pathogens and as source of bioactive metabolites for R. solani suppression.

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Lisangan, M. M., R. Syarief, W. P. Rahayu et O. S. Dharmaputra. « Effect of kebar grass (Biophytum petersianum Klotzsch) leaf extract on the growth and morphological structure of aflatoxigenic Aspergillus flavus ». Food Research 4, n^o 1 (24 juillet 2019) : 234–43. http://dx.doi.org/10.26656/fr.2017.4(1).129.

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The objective of this study was to investigate the antifungal activity of kebar grass (Biophytum petersianum Klotzsch) extract (KGE) on the mycelial growth, conidiation and morphological structure of two types of aflatoxigenic fungus, which are Aspergillus flavus BCCF 0219 and A. flavus BIO 2236. They were isolated in the three types of model media, namely carbohydrate-enriched medium, fat-enriched medium and protein-enriched medium with five concentrations of KGE (12, 14, 16, 18, and 20 mg/mL) on each media. The best extract concentration of that inhibits the growth of A. flavus BCCF 0219 was found in the carbohydrate-enriched medium (95.7%), which was 12 mg/mL, whereas at A. flavus BIO 2236 was found in the fat-enriched medium (100%), which was 16 mg/mL. Based on SEM observation results, it was found that the mechanisms involved in fungal growth inhibitory by the KGE were by morphological alterations of the hyphal development, and the collapse of the entire hyphae. These findings indicated that KGE as a potential natural antifungal agent, particularly against aflatoxigenic fungi.

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Artanti, Nina, Leonardus B. S. Kardono et Sanro Tachibana. « Effect of initial inoculum on growth and fatty acid content as an α-glucosidase inhibitor in Colletotrichum sp. TSC13 mycelium that cultures under shake and static conditions ». Jurnal Kimia Terapan Indonesia 19, n^o 2 (25 janvier 2018) : 49–53. http://dx.doi.org/10.14203/jkti.v19i2.353.

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Colletotrichum species were reported producing various bioactive compounds that may potentially be used in the development of anti-microbial, antioxidant, anticancer and anti-diabetes drugs. Our previous studies showed that the methanol extracts of mycelia from Colletotrichum sp. TSC13, an endophytic fungus isolated from Taxus sumatrana (Miq.) de Laub., were found to have α-glucosidase inhibitory activities. The aim of present study was to examine the effects of initial inoculum on growth and the content of fatty acids as an α-glucosidase inhibitor in Colletotrichum sp. TSC13 that grew under shake and static condition. The results showed that shake and static conditions had more effect compared to the initial inocculum on growth and glucose consumption in growth and glucose consumption. However in terms of fatty acids contents and α-glucosidase inhibitor activities the initial inoculum showed more effect than shake and static conditions

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Morales, Javiera, Ximena Besoain, Italo F. Cuneo, Alejandra Larach, Laureano Alvarado, Alejandro Cáceres-Mella et Sebastian Saa. « Impact of Nitrogen Fertilization on Phytophthora cinnamomi Root-related Damage in Juglans regia Saplings ». HortScience 54, n^o 12 (décembre 2019) : 2188–94. http://dx.doi.org/10.21273/hortsci14299-19.

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Excessive nitrogen (N) use in agriculture has been associated with increased severity of the damage caused by Phytophthora species. In this study, we investigated the impact in vitro and in vivo of N about Phytophthora cinnamomi. The preliminary in vitro assay showed the effect of different N sources on the mycelial growth of P. cinnamomi. This assay indicated that ammonium nitrate (NH4NO3) and ammonium sulfate [(NH4)2SO4] allowed for greater control of P. cinnamomi mycelia in comparison with calcium nitrate [Ca(NO3)2] and potassium nitrate (KNO3) when used with 1000 ppm N. The in vivo assay showed the severity of P. cinnamomi in 5-month-old Juglans regia saplings grown under greenhouse conditions. We selected NH4NH3 as the source for N for the greenhouse assay, considering the inhibitory effect on the ingrowth of P. cinnamomi and the intensive use of this fertilizer in agriculture. Walnut saplings were fertilized with 0, 35, 70, 140, 210, and 1050 ppm N and were inoculated with zoospores of P. cinnamomi 45 d after the application of nitrogen treatment (DAA). They were harvested at 90 DAA. We found that a 70-ppm N fertilization reduced the development of P. cinnamomi, resulting in lower root and canopy damage indices (DIs) than the unfertilized inoculated treatments and fertilized treatments greater than 140 ppm. The results of the in vitro and in vivo assay agree that increased N concentrations were associated with reduced mycelium growth of P. cinnamomi, providing further evidence that N fertilization can mitigate this disease. Greater root and canopy damage was observed in saplings fertilized with 1050 ppm N, regardless of whether they were inoculated with P. cinnamomi, as a result of N phytotoxicity (verified through foliar analysis). In contrast, inoculated and unfertilized saplings (N0) also showed high root and canopy DIs associated either with the inoculation with P. cinnamomi or the no fertilization treatment. We postulate that 70 ppm N is the best fertilization rate for J. regia saplings because the positive effects of N on growth are maximized and the damage caused by P. cinnamomi is mitigated.

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Yin, Hui, Jianbo Zhou, Hong Lv, Nan Qin, Fang Juan Chang et Xiaojun Zhao. « Identification, Pathogenicity, and Fungicide Sensitivity of Ascochyta caulina (Teleomorph : Neocamarosporium calvescens) Associated with Black Stem on Quinoa in China ». Plant Disease 104, n^o 10 (octobre 2020) : 2585–97. http://dx.doi.org/10.1094/pdis-09-19-2042-re.

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Quinoa black stem is a new disease that affects the stems of quinoa plants and is more likely to develop under cool conditions (15 to 25°C, RH = 55 ± 2%). The typical symptoms include the formation of black necrotic lesions on the stem, which can completely wrap around the stem, causing lodging and blanking (development of ‘empty’ and sterile grain on the panicle). Furthermore, the pycnidia form small round protrusions on the surface of the lesions. Phylogenetic analysis revealed that representative isolates LMHS-3 and LMHS-5 were closely related to Ascochyta caulina (teleomorph: Neocamarosporium calvescens). Comprehensive morphological and molecular characterizations confirmed A. caulina as the pathogen that caused quinoa black stem. A. caulina mainly infected quinoa stems and could produce many pycnidia, but it rarely infected quinoa leaves. Pathogenicity testing showed that the most suitable temperature for the onset of quinoa black stem was from 15 to 25°C. When the temperature was increased above 30°C, the conidial germination of A. caulina became malformed, and when the temperature was decreased below 5°C, mycelium growth of A. caulina became extremely slow; thus, both extreme high and low temperatures affected the pathogenicity of A. caulina. Mancozeb and azoxystrobin fungicides were revealed to have had the strongest inhibitory effects on the conidial germination of A. caulina, and in some cases caused malformations in conidial germination. Tebuconazole and difenoconazole had the strongest inhibitory effects on A. caulina mycelial growth and less on the effects on the conidial germination. The results of the present study provide a basis for the recognition and management of quinoa black stem.

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Gao, Y. Y., X. X. Li, L. F. He, B. X. Li, W. Mu et F. Liu. « Effect of Application Rate and Timing on Residual Efficacy of Pyraclostrobin in the Control of Pepper Anthracnose ». Plant Disease 104, n^o 3 (mars 2020) : 958–66. http://dx.doi.org/10.1094/pdis-03-19-0435-re.

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Anthracnose is a devastating disease that seriously affects pepper production worldwide. Anthracnose management is currently a major problem because of the widespread and long period of infection of this disease. Therefore, determination of the optimal fungicide application timing is important for controlling anthracnose in a timely manner . In vitro sensitivity tests showed no significant difference in the pyraclostrobin sensitivity of Colletotrichum scovillei collected from 2016 and 2017, with mean half maximal effective concentration values of 0.349 to 0.542 and 0.0475 to 0.0639 mg/liter for the inhibition of mycelial growth and spore germination, respectively. Fungicide application initiated at the full-bloom stage could significantly delay anthracnose disease onset, decrease anthracnose incidence and development (23.67 to 89.80%), and increase pepper yield by 10.7 to 29.2%. In addition, the application dosage was decreased by >50%. BF-500-3, the main metabolite of pyraclostrobin, was detected in pepper fruit and exhibited high inhibitory activity against C. scovillei. The final residues of all fungicides at different application timing were below maximum residue limits. Moreover, structural equation modeling indicated that application timing plays the most important role in anthracnose disease inhibition. The tank mixtures of pyraclostrobin with tebuconazole and fludioxonil showed more satisfactory efficacy (69.87 to 78.36%) against anthracnose than did pyraclostrobin alone under field conditions. This study is the first to determine the best fungicide application timing for anthracnose management. These results establish the basis for sustainable development of the pepper industry.

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Pinheiro de Menezes, Camilla, Ana Luiza Alves de Lima Perez, Janiere Pereira de Sousa, Julio Abrantes Pereira, Lílian De Souza Pinheiro, Maria Alice Araújo de Medeiros, Millena De Souza Alves, Abrahão Alves de Oliveira Filho et Edeltrudes De Oliveira Lima. « Investigation on mechanism of antifungal activity of citral against Cladosporium sphaerospermum Penz. » Anales de Biología, n^o 44 (4 juillet 2022) : 43–53. http://dx.doi.org/10.6018/analesbio.44.05.

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El objetivo de este estudio fue investigar la actividad antifúngica del citral contra Cladosporium sphaerospermum, mediante la determinación de la concentración mínima inhibitoria (CMI) y la concentración mínima de fungicida (CMF), los efectos sobre el crecimiento micelial y la germinación de conidios, y también investigar la posible acción de citral en paredes celulares y membranas celulares. La CMI del citral varió de 128 a 256 µg/mL y la CMF varió de 256 a 1024 µg/mL. La CMI50 y CMF50 fueron, respectivamente, 128 µg/mL y 256 µg/mL. El citral inhibió el desarrollo micelial y la germinación de conidios y mostró interacción con ergosterol. Estos datos indican que el citral tiene una fuerte actividad antifúngica, que puede estar relacionada con su interacción con el ergosterol. The aim of this study was to investigate the antifungal activity of citral against Cladosporium sphaerospermum, by determining the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC), effects on mycelial growth and conidia germination, and also investigated the possible action of citral in cell walls and cell membranes. The MIC of citral ranged from 128 to 256 µg / ml and the MFC ranged from 256 to 1024 µg/mL. The MIC50 and MFC50 were, respectively, 128 µg/mL and 256 µg/mL. Citral inhibited mycelial development and conidia germination and showed interaction with ergosterol. These data indicate that citral has strong antifungal activity, which may be related to its interaction with ergosterol.

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Chakraborty, Moutoshi, S. M. Fajle Rabby, Dipali Rani Gupta, Mahfuzur Rahman, Sanjoy Kumar Paul, Nur Uddin Mahmud, Abdullah Al Mahbub Rahat, Ljupcho Jankuloski et Tofazzal Islam. « Natural Protein Kinase Inhibitors, Staurosporine, and Chelerythrine Suppress Wheat Blast Disease Caused by Magnaporthe oryzae Triticum ». Microorganisms 10, n^o 6 (9 juin 2022) : 1186. http://dx.doi.org/10.3390/microorganisms10061186.

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Protein kinases (PKs), being key regulatory enzymes of a wide range of signaling pathways, are potential targets for antifungal agents. Wheat blast disease, caused by Magnaporthe oryzae Triticum (MoT), is an existential threat to world food security. During the screening process of natural metabolites against MoT fungus, we find that two protein kinase inhibitors, staurosporine and chelerythrine chloride, remarkably inhibit MoT hyphal growth. This study further investigates the effects of staurosporine and chelerythrine chloride on MoT hyphal growth, conidia production, and development as well as wheat blast inhibition in comparison to a commercial fungicide, Nativo®75WG. The growth of MoT mycelia is significantly inhibited by these compounds in a dose-dependent manner. These natural compounds greatly reduce conidia production in MoT mycelia along with suppression of conidial germination and triggered lysis, resulting in deformed germ tubes and appressoria. These metabolites greatly suppress blast development in artificially inoculated wheat plants in the field. This is the first report of the antagonistic effect of these two natural PKC inhibitory alkaloids on MoT fungal developmental processes in vitro and suppression of wheat blast disease on both leaves and spikes in vivo. Further research is needed to identify their precise mechanism of action to consider them as biopesticides or lead compounds for controlling wheat blast.

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Tian, Yuee, Zhiping Che, Di Sun, Jiaxuan He, Shengming Liu et Xiaomin Lin. « In Vitro Effects of Five Different Classes of Fungicides on Growth and Development of Botrytis cinerea Isolated from Tree Peony in China ». HortScience 54, n^o 11 (novembre 2019) : 1984–88. http://dx.doi.org/10.21273/hortsci14431-19.

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Gray mold caused by Botrytis cinerea has become an important limiting factor for tree peony production. Currently, chemical control is still the main means of managing the disease in China. The objective of this study was to test fungicides with different mechanisms of action in controlling B. cinerea on tree peony. The inhibitory efficacy of five fungicides on four asexual stages was measured in the petri dish containing culture medium amended with a tested fungicide at various concentrations. The results showed that carbendazim had the strongest inhibition effect against all four stages of B. cinerea, with the EC50 values of 0.1037, 0.0563, 0.5578, and 0.0797 mg·L–1, respectively. The inhibitory effect of diethofencarb was only slightly less than that of carbendazim on conidia production, germination, and germ tube elongation. The inhibitory effect of procymidone was second only to that of carbendazim on colony expansion. The results indicated that carbendazim and diethofencarb could be used as protective fungicides to spray in the early stage of disease occurrence to inhibit conidia germination and germ tube elongation, so as to reduce the infection rate of B. cinerea and prevent disease occurrence. Carbendazim, procymidone, and diethofencarb mainly inhibit the reinfection of B. cinerea by inhibiting the growth of mycelium and the production of conidia, so they could be used as control fungicides during the occurrence phase of the disease.

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Li, Zhengpeng, Xiaoning Gao, Zhensheng Kang, Lili Huang, Dongying Fan, Xia Yan et Zhensheng Kang. « Saccharothrix yanglingensis Strain Hhs.015 Is a Promising Biocontrol Agent on Apple Valsa Canker ». Plant Disease 100, n^o 2 (février 2016) : 510–14. http://dx.doi.org/10.1094/pdis-02-15-0190-re.

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Apple Valsa canker (AVC), caused by Valsa mali, results in a serious and persistent disease problem for apple production in China and is difficult to control by chemical and agricultural measures. In this study, we determined the inhibitory effects of an endophytic actinomycete Saccharothrix yanglingensis strain Hhs.015 on V. mali under laboratory and the field conditions. Fermentation broth (FB) of Hhs.015 significantly inhibited conidial germination and mycelial growth, causing malformed and dysfunctional fungal structures. Detached apple (Malus domestica ‘Fuji’) twigs smeared with FB before V. mali inoculation significantly reduced lesion development, especially sporulation. In the orchard trials conducted from 2010 to 2013, trunks and branches smeared with FB three times significantly reduced the number of new lesions. In addition, wounds after lesion surgery coated with FB also enhanced callus formation and significantly improved the cure rate. The results showed that S. yanglingensis Hhs.015 is effective against AVC in orchards. Thus, S. yanglingensis Hhs.015 can be further developed as an effective biocontrol agent for more sustainable management of AVC.

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Lee, Lundoi Tobias, Ana Paula Martinazzo, Sabrinna Aires Garcia, Pedro Amorim Berbet et Carlos Eduardo De Souza Teodoro. « Control of Aspergillus flavus in wheat grains using Cymbopogon flexuosus essential oil ». Acta Brasiliensis 5, n^o 3 (30 septembre 2021) : 92. http://dx.doi.org/10.22571/2526-4338528.

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Fungi are one of the main food spoilage agents. Numerous species when subjected to stress conditions produce secondary metabolites known as mycotoxins, which are mutagenic and carcinogenic substances. The fungus Aspergillus flavus is one of the main contaminants of grains and is known to produce Aflatoxin. Pesticides are used in agriculture to contain fungi and other pests, but they harm other species, the environment and the human health, in addition to the development of resistance to these substances in pest species. Natural alternatives have been sought to control these organisms. In this context, essential oils are a viable option against A. flavus. The aim of this study was to identify the main components and evaluate the effectiveness of lemongrass essential oil (Cymbopogon flexuosus) for controlling the fungus Aspergillus flavus. Initially, the effect of essential oil on mycelial growth of the fungus was assessed by in vitro tests at the doses: 0.05; 0.1; 0.2; 0.4; 0.6; 0.8; 1.6; 3.2; 6.4; and 12.8 μL mL-1. The minimum inhibitory concentration (MIC) was 0.8 μL mL-1. The in vivo test was performed at the following concentrations: 0.6; 0.8; and 1.6 μL mL-1. The results showed that the essential oil has fungicidal potential against A. flavus. The main component of the essential oil was citral.

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Kausar, Farzana, Kyung-Hwan Kim, Hafiz Muhammad Umer Farooqi, Muhammad Awais Farooqi, Muhammad Kaleem, Rooma Waqar, Atif Ali Khan Khalil et al. « Evaluation of Antimicrobial and Anticancer Activities of Selected Medicinal Plants of Himalayas, Pakistan ». Plants 11, n^o 1 (24 décembre 2021) : 48. http://dx.doi.org/10.3390/plants11010048.

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Medicinal plants are known for their diverse use in the traditional medicine of the Himalayan region of Pakistan. The present study is designed to investigate the anticancer and antimicrobial activities of Prunus cornuta and Quercus semicarpifolia. The anticancer activity was performed using cancerous human cell lines (HepG2, Caco-2, A549, MDA-MB-231, and NCI-H1437 carcinoma cells), while the antimicrobial activity was conducted with the agar-well diffusion method. Furthermore, toxicity studies were performed on alveolar and renal primary epithelial cells. Initially, different extracts were prepared by maceration techniques using n-hexane, chloroform, ethyl acetate, butanol, and methanol. The preliminary phytochemical screening showed the presence of secondary metabolites such as alkaloids, tannins, saponins, flavonoids, glycosides, and quinones. The chloroform extract of P. cornuta (PCC) exhibited significant inhibitory activity against Acinetobacter baumannii (16 mm) and Salmonella enterica (14.5 mm). The A. baumannii and S. enterica strains appeared highly susceptible to n-hexane extract of P. cornuta (PCN) with an antibacterial effect of 15 mm and 15.5 mm, respectively. The results also showed that the methanolic extracts of Quercus semecarpifolia (QSM) exhibited considerable antibacterial inhibitory activity in A. baumannii (18 mm), Escherichia coli (15 mm). The QSN and QSE extracts also showed good inhibition in A. baumannii with a 16 mm zone of inhibition. The Rhizopus oryzae strain has shown remarkable mycelial inhibition by PCM and QSN with 16 mm and 21 mm inhibition, respectively. Furthermore, the extracts of P. cornuta and Q. semicarpifolia exhibited prominent growth inhibition of breast (MDA-MB-231) and lung (A549) carcinoma cells with 19–30% and 22–39% cell viabilities, respectively. The gut cell line survival was also significantly inhibited by Q. semicarpifolia (24–34%). The findings of this study provide valuable information for the future development of new antibacterial and anticancer medicinal agents from P. cornuta and Q. semicarpifolia extracts.

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Degani, Ofir, et Ben Kalman. « Assessment of Commercial Fungicides against Onion (Allium cepa) Basal Rot Disease Caused by Fusarium oxysporum f. sp. cepae and Fusarium acutatum ». Journal of Fungi 7, n^o 3 (21 mars 2021) : 235. http://dx.doi.org/10.3390/jof7030235.

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The onion basal rot disease is a worldwide threat caused by species of the genus Fusarium. Today, Israel’s control of this disease is limited to a four-year growth cycle and Metam sodium soil disinfection. Here, commercial chemical fungicides were evaluated as control treatments against two of the primary pathogens involved, F. oxysporum f. sp. cepae and F. Acutatum. Out of 10 fungicides tested on culture plates, 3, Prochloraz, Azoxystrobin + Tebuconazole, and Fludioxonil + Sedaxen, had strong inhibitory effects on mycelial growth and were selected and tested in seeds in vitro. The preparations were applied as a seed coating and tested in two commercial cultivars, Riverside (Orlando, white cv.) and Noam (red cv.). Prochloraz (0.3% w/w concentration), the most promising compound, was efficient in reducing the Noam cv. sprouts’ disease symptoms. This preparation had no harmful in situ-toxicity effect and did not influence the plants’ seed germination and early development. In Noam cv. potted 30-day-old sprouts, the Prochloraz treatment was able to reduce the harmful impact of F. oxysporum f. sp. cepae. on the seedlings’ wet biomass, but was not effective in the Riverside cv. or against the F. acutatum pathogen. This suggests that future protective strategies must include an effective protective suit tailored to each of the pathogen species involved and the onion cultivar. The methods presented in this work can be applied for rapidly scanning multiple compounds while gradually ruling out ineffective ones. Eventually, this screening will enable field testing of the highest potential fungicides that successfully pass the pot experiments.

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Safari Motlagh, Mohammad Reza, Maryam Farokhzad, Behzad Kaviani et Dariusz Kulus. « Endophytic Fungi as Potential Biocontrol Agents against Sclerotium rolfsii Sacc.—The Causal Agent of Peanut White Stem Rot Disease ». Cells 11, n^o 17 (25 août 2022) : 2643. http://dx.doi.org/10.3390/cells11172643.

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Peanut stem white rot caused by Sclerotium rolfsii Sacc. is a soil-borne disease that is widely prevailing across peanut farms, leading to serious economic losses. Screening for biocontrol agents against this pathogen is urgent. In this research, 166 fungal isolates including 136 isolates of S. rolfsii and 30 isolates of antagonistic endophytic fungi were obtained from a total of 220 samples collected from peanut farms in Guilan province, Iran. After morphological and molecular identification, six superior endophytic isolates were finally selected for the in vitro and greenhouse trials, including four isolates from Trichoderma viride, Trichoderma virens, Penicillium decaturense, and Aspergillus flavus and two isolates from Penicillium rubens. Four methods of biocontrol were used during the in vitro phase, i.e., dual culture, volatile metabolites assay, non-volatile metabolites assay (culture extract), and slide culture. It was found that T. virens had the highest capability of suppressing the mycelial growth of S. rolfsii in the dual culture method (90.98%). As for the volatile metabolites assay, the most effective isolates in inhibiting the pathogen’s mycelial growth were P. rubens (MN395854.1) and A. flavus (84.30% and 73.50% inhibition, respectively). In the non-volatile metabolites method, the isolates that performed the best in suppressing the mycelial growth of S. rolfsii were T. viride and P. rubens (MN395854.1) with 91.80% and 90.20% inhibitory effects, respectively. On the other hand, in the slide culture method, all isolates, except for T. virens and T. viride, successfully controlled the development of S. rolfsii hyphae. The greenhouse trials also supported the effectiveness of endophytic fungi in controlling the pathogen on the host plants. According to the results, T. viride, A. flavus, and P. rubens (MN395854.1) were 44%, 42%, and 38% effective in alleviating the disease incidence and severity. Moreover, the application of these antagonistic fungi in the greenhouse conditions increased the height, fresh weight, and dry weight of the Arachis hypogaea plants infected with the disease causal agent compared to the plants treated only with the pathogen. The results of the in vitro and greenhouse experiments revealed that the endophytic fungi occurring in the natural microbiota of peanut are capable of bio-controlling S. rolfsii, the causal agent of peanut stem white rot disease. These findings shed new insights into the possible resistance induction in A. hypogaea plants through biological protection.

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Saniewska, Alicja, Marcin Horbowicz et Marian Saniewski. « The effect of salicylic acid and acetylsalicylic acid on red pigment formation in mechanically wounded scales of Hippeastrum x hybr. hort. and on the growth and development of Phoma narcissi ». Acta Agrobotanica 58, n^o 2 (2012) : 81–90. http://dx.doi.org/10.5586/aa.2005.035.

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Various organs of Hippeastrum infected by Phoma narcissi, infested with mite, Steneotarsonemus laticeps or mechanically wounded, produce red pigment on the surface of injured tissues. The aim of the present work was to study the effect of salicylic (SA) and acetylsalicylic acids (ASA) (inhibitors of biosynthesis of jasmonates and ethylene) on red pigment formation in wounded scales of bulbs of Hippeastrum and on the mycelium growth of P. narcissi in vivo and in vitro. SA and ASA at a concentration of 1 and 2 mM partially inhibited the formation of red pigment in wounded scales, first of all in first 2 days after treatment. The growth and development of P. narcissi on basal plate and scales of longitudinally cut Hippeastrum bulb treated with SA and ASA (1 and 2 mM) was similar as in control. SA (50 µg·cm-3) and ASA (250 µg·cm-3) inhibited the mycelium growth of P. narcissi on PDA medium, and concentration of 1000 µg·cm-3 of both almost totally inhibited the mycelium growth of the pathogen. Inhibitory effect of SA and ASA on the formation of red pigment in wounded scales of Hippeastrum may be caused by lowered biosynthesis and accumulation of jasmonates.

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Abou-Salem, Eman, Abdulmageed R. Ahmed, Mohssen Elbagory et Alaa El-Dein Omara. « Efficacy of Biological Copper Oxide Nanoparticles on Controlling Damping-Off Disease and Growth Dynamics of Sugar Beet (Beta vulgaris L.) Plants ». Sustainability 14, n^o 19 (9 octobre 2022) : 12871. http://dx.doi.org/10.3390/su141912871.

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One of the most prevalent diseases affecting sugar beet crops globally is damping-off disease, which is caused by fungi or soil-borne bacteria. The objective of the current study was to assess the antimicrobial activity of various concentrations of CuO-NPs against Fusarium oxysporum, Macrophomina phaseolina, and Pectobacterium carotovorum in a lab setting and how they influenced vegetative growth, physiological traits, antioxidant enzymes, disease incidence percentage, and mineral nutrients of sugar beet plants in a greenhouse experiment. Sugar beet (Beta vulgaris cv. Oscar poly) seeds were soaked in different concentrations (50, 100, and 150 µg L−1) of the tested NPs for two hours pre-sowing. According to in vitro studies, as compared to aqueous copper sulphate and control, CuO-NPs at 25, 35, and 100 µg mL−1 had the greatest inhibitory effect (100%) on the mycelial growth of M. phaseolina, F. oxysporum, and P. carotovorum, respectively. Results from the greenhouse experiment showed that the 150 µg mL−1 concentration produced the greatest reduction in disease incidence %, with efficacy values of 24.53, 13.25, and 23.59% for F. oxysporum, M. phaseolina, and P. carotovorum, respectively. In addition, as compared to untreated control plants, the same concentration of CuO-NPs significantly (p ≤ 0.05) increased the vegetative development, physiological characteristics, antioxidant enzymes, and mineral nutrients of sugar beet plants. Therefore, the antimicrobial activity demonstrated by the biosynthesized CuO NPs indicates that they can resist plant pathogenic microorganisms of sugar beet plants.

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Kwon, Jun-Hyeok, Sang-Jae Won, Jae-Hyun Moon, Chul-Woo Kim et Young-Sang Ahn. « Control of Fungal Diseases and Increase in Yields of a Cultivated Jujube Fruit (Zizyphus jujuba Miller var. inermis Rehder) Orchard by Employing Lysobacter antibioticus HS124 ». Forests 10, n^o 12 (15 décembre 2019) : 1146. http://dx.doi.org/10.3390/f10121146.

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The objective of this study is to investigate the inhibitory effects of Lysobacter antibioticus HS124 on fungal phytopathogens causing gray mold rot, stem rot, and anthracnose. Another objective of this study is to promote the yield of fruit in jujube farms. L. antibioticus HS124 produces chitinase, a lytic enzyme with the potential to reduce mycelial growth of fungal phytopathogens involving hyphal alterations with swelling and bulbous structures, by 20.6 to 27.3%. Inoculation with L. antibioticus HS124 decreased the appearance of fungal diseases in jujube farms and increased the fruit yield by decreasing fruit wilting and dropping. In addition, L. antibioticus HS124 produced the phytohormone auxin to promote vegetative growth, thereby increasing the fruit size. The yield of jujube fruits after L. antibioticus HS124 inoculation was increased by 6284.67 g/branch, which was 2.9-fold higher than that of the control. Auxin also stimulated fine root development and nutrient uptake in jujube trees. The concentrations of minerals, such as K, Ca, Mg, and P in jujube fruits after L. antibioticus HS124 inoculation were significantly increased (1.4- to 2.0-fold greater than the concentrations in the control). These results revealed that L. antibioticus HS124 could not only control fungal diseases but also promote fruit yield in jujube farms.

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Stack, Abigail J., Meera Madra, Thomas R. Gordon et Richard M. Bostock. « Seasonal Variation in Host Susceptibility to Fusarium Canker in Young Almond Trees ». Plant Disease 104, n^o 3 (mars 2020) : 772–79. http://dx.doi.org/10.1094/pdis-06-19-1292-re.

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Loss of water that reduces the relative water content (RWC) of bark can occur during processing, cold storage, and planting of bare-root stone fruit trees. In California nurseries and newly planted orchards, this stress can predispose young almond trees (Prunus dulcis) to a canker disease caused primarily by Fusarium species. While reduced bark RWC contributes to disease development, anecdotal observations suggest a seasonal effect on host physiology may also influence disease severity. We evaluated the effect of season and the impact of drying and reduced RWC on susceptibility of almond branch segments excised from orchard trees (cv. Nonpareil) to Fusarium acuminatum, Fusarium avenaceum, Fusarium brachygibbosum, and Fusarium californicum sp. nov. With lesion size as the criterion, excised inoculated branch segments were most susceptible in spring, of intermediate susceptibility during winter dormancy, and least susceptible during summer and fall. Consistent with an earlier study, branches with RWC between 80 and 85% yielded lesions that were significantly larger than lesions from branches with bark that was above or below that range. However, the effect of reduced bark moisture on lesion size was only apparent in the spring. These results affirm the importance of avoiding conditions that diminish moisture status in bare-root almond trees in Fusarium canker disease management, especially during transport and planting operations in the spring, a period of high physiological vulnerability. California nurseries apply fungicides to bare-root trees prior to cold storage to reduce “mold” growth. Of eight fungicides currently registered for use on almond trees, fludioxonil (Scholar), fluopyram/trifloxystrobin (Luna Sensation), and fluxapyroxad/pyraclostrobin (Merivon) were most inhibitory to in vitro mycelial growth of F. acuminatum, F. avenaceum, and F. brachygibbosum. However, our almond branch disease assay did not demonstrate preventive or curative fungicide action against infections by F. acuminatum or F. avenaceum.

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Costantin, Clarice Rech, Helena Gil de Oliveira, Luiza San Martins Roese, Márcia Regina Pancera, Wendel Paulo Silvestre, Gustavo Rubbo Siqueira, Nadilson Roberto Ferreira et Valdirene Camatti Sartori. « Evaluation of the antifungal activity of propolis extracts from stingless bees on phytopathogenic fungi ». Research, Society and Development 11, n^o 16 (14 décembre 2022) : e445111638445. http://dx.doi.org/10.33448/rsd-v11i16.38445.

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The bees of the Meliponini tribe, known as stingless bees (SB), elaborate a distinct type of propolis, whose application potential is largely unexplored. Currently, there is some knowledge of the pharmacological activities of the propolis from Apis mellifera, however, little is known about the diversity and antimicrobial activity of Meliponini propolis, especially in relation to pathogens of agricultural importance. This study aimed to investigate the antimicrobial activity of the alcoholic extract of propolis from T. clavipes (Borá), S. bipunctata (Tubuna), and T. angustula (Jataí), comparing with the ethanolic extract from A. mellifera propolis. The autoclaved and non-autoclaved extracts were evaluated at the concentrations of zero, 1.6 %; 3.2 %; 6.4 %, and 12.0 % v/v. Fungal development was determined by measuring the mycelial diameter up to the fourteenth day of inoculation, with five replicates; the growth inhibition was calculated relative to the control. According to the results, the highest concentration of phenolic compounds and flavonoids was present in the ethanolic extract of A. mellifera propolis when compared to the SB extracts. The results indicated an inhibitory effect on the growth of the phytopathogens Colletotrichum gloeosporioides, Fusarium sp., Botryosphaeria sp., and Botrytis sp., mainly from 6.4 % and 12.0 % v/v when evaluated in the non-autoclaved medium, followed by the autoclaved medium. The fungus Botrytis sp. was the phytopathogen that suffered greater inhibition from 3.2 mL∙L-1, with the T. angustula propolis extract. The obtained results demonstrate that the alcoholic extracts of propolis from SB have the potential to control phytopathogenic fungi of agricultural interest.

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Pap, P., B. Rankovic et S. Masirevic. « Effect of temperature, relative humidity and light on conidial germination of oak powdery mildew (Microsphaera alphitoides Griff. et Maubl.) under controlled conditions ». Archives of Biological Sciences 65, n^o 3 (2013) : 1069–77. http://dx.doi.org/10.2298/abs1303069p.

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The influence of temperature, humidity and light on the conidial germination and germ tube elongation of oak powdery mildew (Microsphaera alphitoides Griff. et Maubl.) was studied in controlled conditions. The maximal germ tube length was attained at 25?C, whereas at lower and higher than optimal temperatures, germ tube growth was significantly lower. Germ tubes begin to develop at all values of relative humidity (10-100%), reaching the maximum length at 90%. The development of germ tubes was the most intense in full light and the lowest in total darkness. The artificial infection of floating leaves showed that an increasing age had an inhibitory effect on the mycelium development and spore formation. Since conidia play a crucial role in powdery mildew epidemiology, it is of particular importance to elucidate the influence of environmental factors in the complex relations that exist between the plant and its pathogen.

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Uddin, Muhammad Nazir, Saifullah Saifullah, Musharaf Ahmad, Wajid Khan et Bilal Muhammad Khan. « Evaluation of Pochonia chlamydosporia (Goddard) Isolates for Suppression of Meloidogyne incognita, Root-Knot Nematode of Tomato ». Journal of Agricultural Science 11, n^o 5 (15 avril 2019) : 70. http://dx.doi.org/10.5539/jas.v11n5p70.

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Restricted applications of chemical nematicides has directed to the development of ecofriendly alternatives. Culture filtrates in different concentrations (20, 40, 60, 80 and 100%) of the six isolates of Pochonia chlamydosporia were evaluated for their nematicidal activity. Significant variations were observed in the inhibitory activity of culture filtrates against egg hatching and second stage juveniles of M. incognita at different concentrations. The culture extract of PC-6 showed maximum inhibition of egg hatching followed by PC-1. On the other hand PC1 isolate caused high mortality of second stage juveniles followed by PC-6. Significant variation among the isolates was observed for parasitism of M. incognita juveniles and eggs. Among the tested isolates, PC-1 and PC-6 were selected for the further studies based on in vitro egg inhibition and larval mortality. Both PC1 and PC6 applied at the rate of 6 × 103 chlamydospores per gram of soil per plant reduced the population of nematode and improved the growth and productivity of plant under screen house and field conditions. Different growth parameters like plant height, fresh shoot weight, dry shoot weight, fresh root weight and dry root weight were measured. Efficacy of isolates was different in winter and summer crop. No significant difference among the treatments was observed in summer crop. However in winter crop, considerable effect of both isolates was observed. Fungal application was effective at the rate of 6 × 103 chlamydospores per gram of soil per plant in both winter and summer crops. Root coating with chlamydospores suspension significantly reduced number of galls on roots. Little effect of both isolates was observed with mycelial root coating. No lesions were seen on P. chlamydosporia inoculated roots of tomato plants.

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