scholarly journals Effet de l’association de certains fongicides avec le chlorure de calcium sur le développement d’un complexe fongique responsable de la pourriture des pommes en conservation

2007 ◽  
Vol 88 (1) ◽  
pp. 17-26 ◽  
Author(s):  
Khaled Attrassi ◽  
Rachid Benkirane ◽  
Benaissa Attrassi ◽  
Allal Douira

L’utilisation du bénomyl et du thiabendazole (famille chimique des benzimidazoles), de l’azoxystrobine et du pyriméthanil montre, autant in vitro qu’in vivo, que ces fongicides sont faiblement à moyennement efficaces contre les agents pathogènes suivants : Rhizopus stolonifer, Penicillium expansum, Aspergillus niger, A. fumigatus, Alternaria alternata, Cladosporium herbarum, Fusarium oxysporum, Saccharomyces cerevisiae, Monilia fructigina, Cryptosporiopsis malicorticis, Spilocaea pomi et Trichothecium roseum. Utilisé in vitro, le chlorure de calcium seul à plus de 4 % est toléré par les douze espèces fongiques. In vivo et à basse température, le chlorure de calcium est efficace lorsqu’utilisé à 4 et 6 %. L’association de ces fongicides avec le chlorure de calcium (4 %) permet de diminuer l’intensité des lésions causées par la pourriture des pommes en conservation. Le chlorure de calcium apparaît intervenir en renforçant les liens avec les principaux sites d’action des fongicides de l’agent pathogène évalué.

2006 ◽  
Vol 31 (2) ◽  
pp. 158-163 ◽  
Author(s):  
Derblai Casaroli ◽  
Danton C. Garcia ◽  
Marlove F. B. Muniz ◽  
Nilson L. de Menezes

O trabalho teve como objetivos avaliar e correlacionar a qualidade sanitária e fisiológica de sementes de abóbora, variedade Menina Brasileira (Cucurbita moschata.). Foram avaliados dois lotes de sementes de abóbora produzidas no sistema agroecológico e quatro no sistema convencional, com e sem tratamento químico. Os lotes foram submetidos aos testes de sanidade, seguindo a metodologia do "Blotter test", com congelamento, germinação e vigor (primeira contagem, índice de velocidade de germinação, envelhecimento acelerado e emergência de plântulas). Os resultados indicaram a separação dos lotes de diferentes origens a partir da qualidade sanitária e fisiológica, onde as maiores incidências de fungos foram observadas nos lotes agroecológicos e o maior potencial fisiológico foi observado nos lotes de origem convencional não tratados. Foram encontrados os fungos Fusarium oxysporum, Alternaria alternata, Cladosporium cucumerinum, Aspergillus niger, Penicillium digitatum, Rhizopus stolonifer e Phoma terrestris. A qualidade sanitária não interferiu na qualidade fisiológica das sementes de abóbora, variedade Menina Brasileira.


2016 ◽  
Vol 23 ◽  
pp. 19-27 ◽  
Author(s):  
Roshan Chhetri ◽  
Sanjay Kumar Jha

Nine hundred sixty seeds of lentils (Lens culinaris) from three different storage sources were tested for seed fungi using Potato Dextrose Agar (PDA) and Blotter technique. Thirty five different fungi were isolated, PDA method being better than Blotter technique. Seeds from traditional village storage were found to be more infested with fungi than source local market and source Nepal Agricultural Research Centre (NARC). The fungal infestation on seeds from village storage was 49.37%, source NARC was 44.37% and source local market was 30.31%. Aspergillus flavus, Aspergillus niger, Alternaria alternata, Penicillium chrysogenum and Fusarium oxysporum were the fungi having higher incidence and frequency. Surface disinfection by 2% NaOCl reduced the fungal incidence and frequency. The aqueous extract of three plants viz, Ageratum houstonianum, Eclipta prostrata and Vitex negundo at 25%, 50% and 100% concentration were assessed in-vitro for antifungal activity against Alternaria alternata, Aspergillus niger, Chaetomium funicola and Fusarium oxysporum. Among these fungi, Alternaria alternata was best controlled by Ageratum houstonianum; Aspergillus niger by Eclipta prostrata; Fusarium oxysporum by Vitex negundo and Ageratum houstonianum. The inhibition increased from lower concentration (25%) to higher (100%).ECOPRINT 23: 19-27, 2016


2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Laila Muñoz Castellanos ◽  
Nubia Amaya Olivas ◽  
Juan Ayala-Soto ◽  
Carmen Miriam De La O Contreras ◽  
Miriam Zermeño Ortega ◽  
...  

In this study, hydrodistillation was used to obtain essential oils (EOs) from pepper (Piper nigrum L.) and clove (Eugenia caryophyllata) and co-hydrodistillation (addition of fatty acid ethyl esters as extraction co-solvents) was used to obtain functional extracts (FEs). Antifungal activity of EOs and FEs was evaluated by determination of minimum inhibitory concentration (MIC) against Fusarium oxysporum and Aspergillus niger. The results showed that pepper (Piper nigrum) and clove (Eugenia caryophyllata) essential oils and their functional extracts are effective in vitro at concentrations from 400 to 500 ppm after 10 days of culturing. The essential oils and functional extracts were used on tomato fruit samples at three different concentrations: 350, 400, and 450 ppm5. Clove essential oil reduced the growth of Aspergillus niger from 50% to 70% and Fusarium oxysporum to 40%. The functional extracts (FEs) of clove and pepper, mixed with ethyl decanoate (FEs-C10), were the best combination for protecting the tomato fruit in vivo against both phytopathogenic fungi. Gas chromatography-mass spectrometry (GC-MS) was used to identify eugenol as the principal compound in clove oil and limonene, sabinene, and β-caryophyllene in pepper oil.


2020 ◽  
Vol 97 (2) ◽  
pp. 119-124
Author(s):  
Diana Hristova ◽  
Yana Kandova ◽  
Georgi Nikolov ◽  
Bogdan Petrunov

Introduction. In Bulgaria, mold allergies are common, and sensitization to different fungal species is found in many patients with atopy.The objective of this study is to explore sensitization to the most widespread mold species in Bulgaria, and to determine the extent of sensitization to Alt a1, a major allergen of Alternaria alternata, by using component-resolved diagnosis.Materials and Methods. 21 patients (14 males and 7 females, age range 5-40 years), with respiratory allergy participated in the study. All patients are sensitized to mix of fungal allergens containing: Alternaria alternata, Aspergillus sp., Cladosporium herbarum, Penicillium notatum, proved by in vivo and in vitro methods. All patients underwent the ImmunoCAP test and were assessed for sIgE to individual fungal allergens: m1 Penicillium notatum, m2 Cladosporium herbarum, m3 Aspergillus fumigatus and m6 Alternaria alternata. The component-resolved diagnosis to Alt a1 was performed for 10 patients with increased sIgE to m6 Alternaria alternata.Results. All studied patients (100%) had elevated sIgE to Alternaria alternata. Eight (38%) patients were sensitized to Penicillium notatum. 11 (52%) and 10 (48%) patients were sensitized to Cladosporium herbarum and to Aspergillus fumigatus, respectively. Ten patients (48%) were monosensitized to Alternaria alternata. Nine (90%) patients with sensitization to Alternaria alternata demonstrated elevated levels of IgE to Alt a1.Conclusion. Alternaria alternata most often causes sensitization in patients with respiratory allergy. The component-resolved diagnosis using Alt a1 is a precision marker to prove species-specific sensitization to Alternaria alternata.


2019 ◽  
Vol 15 (7) ◽  
pp. 662-671 ◽  
Author(s):  
Nabila A. Sebaa ◽  
Amina T. Zatla ◽  
Mohammed E.A. Dib ◽  
Boufeldja Tabti ◽  
Jean Costa ◽  
...  

Background: Bellota species are used to treat various diseases in traditional folk medicine. Objectives: This study aimed to chemically characterize the essential oils and the hydrosol extract and regional specificity of the major components of Ballota nigra essential oil and to evaluate their in vitro and in vivo antifungal activities. Methods: Essential oils were obtained by a Clevenger-type apparatus and analyzed by using Gas Chromatography (GC) and Gas Chromatography Mass Spectroscopy (GC/MS). The antifungal activities were tested to three phytopathogenic stains (Penicillium expansum, Aspergillus niger and Alternaria alternata). Results: Altogether, 38 compounds were identified in the essential oils, representing 92.1-96.8% of the total oil composition. Their main constituents were E-β-caryophyllene (4.8-24.6%), E-β-farnesene (3.3-22.9%), β-bisabolene (7.6-30.2%), α-humulene (2.1-13.3%) and geranyl linalool (1.1-8.2%). The statistical methods deployed confirmed that there is a relation between the essential oil compositions and the harvest locations. Hydrosol extract was constituted by seven components, represented principally by methyl eugenol (75.2%) and caryophyllene oxide (12.5%). The results of in vitro antifungal activity with essential oil and hydrosol extract have shown very interesting antifungal activities on Penicillium expansum and Alternaria alternata strains with percentage reductions up to 80%. Additionally, in in vivo assays, Ballota nigra essential oil and hydrosol extract significantly reduce decay in artificially inoculated tomato by Alternaria alternata. Conclusion: The essential oil and hydrosol extract can be used as a potential source of sustainable eco-friendly botanical fungicides to protect stored tomatoes from pathogens, saprophytic fungi causing bio-deterioration to a variety of food commodities.


2020 ◽  
Vol 18 (3) ◽  
pp. 285-293
Author(s):  
Amina Tabet Zatla ◽  
Imane Mami ◽  
Mohammed El Amine Dib ◽  
Mohammed El Amine Sifi

Background: The microorganisms such as Penicillium expansum and Botrytis cinerea are wellknown pathogens in apples during postharvest. So, to protect apples from these pathogens, chemical control methods were exercised. Introduction: The main objective of this work was to study the chemical composition and the in-vitro and in-vivo antifungal properties of essential oil and hydrosol extract of Marrubium vulgare. Methods: In this work, the air-dried aerial parts of Marrubium vulgare were hydrodistilled in a Clevengertype apparatus. The essential oil and hydrosol extract isolated were analyzed using Gas Chromatography (GC) and Mass Spectrometry (GC/MS). The in-vitro antifungal activity of the both extracts was investigated against Botrytis cinerea, Penicillium expansum and Alternaria alternata fungi using radial growth technique. The effect of the essential oil and hydrosol extract on disease development of apple caused by Penicillium expansum in the in-vivo conditions was assessed. Results: The essential oil of Marrubium vulgare was characterized principally by E-β-caryophyllene (23.5%), E-β-farnesene (21%), α-humulene (14.8%), β-bisabolene (11.1%), caryophyllene oxide (6.8%) and phytol (3.1%). While, the methyl-eugenol (65.5%), α-Bisabolol (12.5%), linalool (6.5%) and caryophyllene oxide (6.2%) were the major compounds of hydrosol extract. The result of in-vitro antifungal activity of hydrosol extract showed an interesting antifungal inhibition against Botrytis cinerea, Penicillium expansum and Alternaria alternata with percentage inhibition ranging from 77% to 89% at low concentration of 0.15 mL/L. The essential oil was found to inhibit the growth of Penicillium expansum in a dose-dependent manner, with a percentage inhibition of 100% at 30 mL/L. Furthermore, essential oil and hydrosol extract have demonstrated promising in-vivo antifungal activity to control infection of apples by Penicillium expansum up to 25th day of storage, compared with the control. Conclusion: The preventive and protective effects of essential oil and hydrosol extract could be exploited as an ideal alternative to synthetic fungicides for using the protection of stored apples from fungal phytopathogens.


2018 ◽  
Vol 114 (1) ◽  
pp. 112-125
Author(s):  
Barbara Wójcik-Stopczyńska ◽  
Barbara Jakubowska

W pracy oceniono skład chemiczny oraz aktywność przeciwgrzybową suszonych ziół przyprawowych – bazylii, oregano, rozmarynu i tymianku. Susze zakupiono w sieci handlowej w opakowaniach jednostkowych. W wymieszanym i rozdrobnionym materiale oznaczono zawartość: suchej masy, białka ogółem, cukrów ogółem, polifenoli ogółem i olejków eterycznych. Do oceny aktywności przeciwgrzybowej użyto 12 szczepów grzybów: Alternaria alternata., Aspergillus flavus, A. fumigatus, A. niger, Cladosporium herbarum, Fusarium oxysporum, Penicillium cyclopium oraz Eurotium amstelodami, E. chevalieri, E. herbariorum, E. repens, E. rubrum. W przypadku grzybów z rodzaju Eurotium stosowano podłoże Agar DG18, a w pozostałych – Malt Extract Agar. Na podłożach zawierających dodatek suszu (1 %) prowadzono doświadczalne hodowle grzybów, a na podłożach bez suszu – hodowle kontrolne. Próbę kontrolną pozytywną stanowił benzoesan sodu (0,05 %). W 3. 6. i 9. dobie inkubacji mierzono średnice kolonii doświadczalnych oraz kontrolnych i obliczano procentową inhibicję wzrostu grzybów powodowaną przez susze. Stwierdzono, że aktywność przeciwgrzybowa była zróżnicowana w zależności od rodzaju suszu, gatunku grzyba i czasu inkubacji. W 9. dniu doświadczenia susz z oregano odznaczający się największą zawartością olejku (2,40 % s.m.) i dużą zawartością polifenoli (4,06 % s.m.) powodował istotnie największe średnie zahamowanie wzrostu zarówno grzybów Eurotium ssp. (95,5 %), jak i pozostałych grzybów (90,2 %). Susz bazyliowy o najmniejszej zawartości olejku i polifenoli, a największej – białka ogółem stymulował wzrost części grzybów. Badane susze powodowały największe zahamowanie wzrostu kolonii A. fumigatus, A. alternata i E. amstelodami, a najmniejsze – A. niger i E. rubrum. Hamowanie wzrostu grzybów malało wraz z czasem inkubacji, ale różnice między średnim zahamowaniem wzrostu grzybów w 6. i 9. dniu hodowli były nieistotne. Susze z oregano, tymianku i rozmarynu efektywniej hamowały wzrost kolonii grzybów niż benzoesan sodu.


2007 ◽  
Vol 6 (12) ◽  
pp. 2214-2221 ◽  
Author(s):  
Lois M. Douglas ◽  
Li Li ◽  
Yang Yang ◽  
A. M. Dranginis

ABSTRACT The Flo11/Muc1 flocculin has diverse phenotypic effects. Saccharomyces cerevisiae cells of strain background Σ1278b require Flo11p to form pseudohyphae, invade agar, adhere to plastic, and develop biofilms, but they do not flocculate. We show that S. cerevisiae var. diastaticus strains, on the other hand, exhibit Flo11-dependent flocculation and biofilm formation but do not invade agar or form pseudohyphae. In order to study the nature of the Flo11p proteins produced by these two types of strains, we examined secreted Flo11p, encoded by a plasmid-borne gene, in which the glycosylphosphatidylinositol anchor sequences had been replaced by a histidine tag. A protein of approximately 196 kDa was secreted from both strains, which upon purification and concentration, aggregated into a form with a very high molecular mass. When secreted Flo11p was covalently attached to microscopic beads, it conferred the ability to specifically bind to S. cerevisiae var. diastaticus cells, which flocculate, but not to Σ1278b cells, which do not flocculate. This was true for the 196-kDa form as well as the high-molecular-weight form of Flo11p, regardless of the strain source. The coated beads bound to S. cerevisiae var. diastaticus cells expressing FLO11 and failed to bind to cells with a deletion of FLO11, demonstrating a homotypic adhesive mechanism. Flo11p was shown to be a mannoprotein. Bead-to-cell adhesion was inhibited by mannose, which also inhibits Flo11-dependent flocculation in vivo, further suggesting that this in vitro system is a useful model for the study of fungal adhesion.


1993 ◽  
Vol 13 (11) ◽  
pp. 6866-6875 ◽  
Author(s):  
D C Hagen ◽  
L Bruhn ◽  
C A Westby ◽  
G F Sprague

Transcription activation of alpha-specific genes in Saccharomyces cerevisiae is regulated by two proteins, MCM1 and alpha 1, which bind to DNA sequences, called P'Q elements, found upstream of alpha-specific genes. Neither MCM1 nor alpha 1 alone binds efficiently to P'Q elements. Together, however, they bind cooperatively in a manner that requires both the P' sequence, which is a weak binding site for MCM1, and the Q sequence, which has been postulated to be the binding site for alpha 1. We analyzed a collection of point mutations in the P'Q element of the STE3 gene to determine the importance of individual base pairs for alpha-specific gene transcription. Within the 10-bp conserved Q sequence, mutations at only three positions strongly affected transcription activation in vivo. These same mutations did not affect the weak binding to P'Q displayed by MCM1 alone. In vitro DNA binding assays showed a direct correlation between the ability of the mutant sequences to form ternary P'Q-MCM1-alpha 1 complexes and the degree to which transcription was activated in vivo. Thus, the ability of alpha 1 and MCM1 to bind cooperatively to P'Q elements is critical for activation of alpha-specific genes. In all natural alpha-specific genes the Q sequence is adjacent to the degenerate side of P'. To test the significance of this geometry, we created several novel juxtapositions of P, P', and Q sequences. When the Q sequence was opposite the degenerate side, the composite QP' element was inactive as a promoter element in vivo and unable to form stable ternary QP'-MCM1-alpha 1 complexes in vitro. We also found that addition of a Q sequence to a strong MCM1 binding site allows the addition of alpha 1 to the complex. This finding, together with the observation that Q-element point mutations affected ternary complex formation but not the weak binding of MCM1 alone, supports the idea that the Q sequence serves as a binding site for alpha 1.


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