Search results for "pathogenic fungi"
showing 10 items of 10 documents
Pathogenicity bioassays of isolates of Beauveria bassiana on Rhynchophorus ferrugineus
2012
BACKGROUND:The control ofRhynchophorusferrugineus (Olivier), themainpalmpest in theMediterraneanBasin, is problematic because of its biology and the current restrictions inmany European countries on the use of chemical insecticides in urban areas. Entomopathogenic fungi have been studied as potential biological control agents, but information on their natural incidence is limited. Strains of Beauveria bassiana (Balsamo) Vuillemin were isolated from symptomatic insects collected on dead palms, and their pathogenicity against different instars of R. ferrugineus was evaluated in the laboratory. RESULTS: The overall percentage of infected insects found in Canary palms was 7%. In laboratory bioa…
Interactions between dark septate endophytes, ectomycorrhizal fungi and root pathogens in vitro
2019
ABSTRACT Dark septate endophytes (DSEs) are widely distributed worldwide and can promote plant growth. Therefore, they are considered potentially important plant allies, especially in stressful environments. Previous studies have reported that DSEs cohabit roots with other microorganisms such as ectomycorrhizal (ECM), endophytic and pathogenic fungi/oomycetes. However, interactions between different DSE species have not yet been reported, and studies on the interactions between DSEs and other fungi are scarce. Using a simple and reproducible pairwise growth assay in vitro, we studied the synergistic/antagonistic interactions between eight DSEs, two ECM fungi and three root pathogens. Most o…
Biocontrol of Phelipanche ramosa, a parasitic weed of rapeseed in France, using soil-borne fungi
2021
National audience; Phelipanche ramosa is a major holoparasitic weed, which became a major agronomic problemfor rapeseed crops in France. Weed control in rapeseed does not have a direct impact on thisparasitic weed whose half of the reproductive cycle occurs on the root system of its host. Since1990, broomrape expanded its distribution area starting from the Poitou-Charentes region.Necrosis symptoms on broomrapes from this region should be indicators of potentialpathogenic fungi. Furthermore, these pathogenic fungi should be able to infest differentbroomrape stages. The aim of my thesis is to contribute to the evaluation of an integrated controlsolution for this parasitic weed and focus on t…
Identification of Novel Hexapeptides Bioactive against Phytopathogenic Fungi through Screening of a Synthetic Peptide Combinatorial Library
2002
The purpose of the present study was to improve the antifungal activity against selected phytopathogenic fungi of the previously identified hexapeptide PAF19. We describe some properties of a set of novel synthetic hexapeptides whose D-amino acid sequences were obtained through screening of a synthetic peptide combinatorial library in a positional scanning format. As a result of the screening, 12 putative bioactive peptides were identified, synthesized, and assayed. The peptides PAF26 (Ac-rkkwfw-NH(2)), PAF32 (Ac-rkwhfw-NH(2)), and PAF34 (Ac-rkwlfw-NH(2)) showed stronger activity than PAF19 against isolates of Penicillium digitatum, Penicillium italicum, and Botrytis cinerea. PAF26 and PAF3…
Fungi related to larvae of red palm weevil Rhynchophorous ferrugineus (Coleoptera: Curculionidae)
2010
As a first step to developing effective biocontrol strategies, we analyzed the pathogens and mainly the entomopathogenic fungal species, present into dead larvae of Rhynchophorous ferrugineus; a quarantine pest recently introduced and acclimated in Sicily (Italy). From 2008 to 2010, we estimated the natural larval mortality (> second instar) of R. ferrugineus collected from infested palm Phoenix canariensis; that was variable from 10 to 35%, according to the different seasons Among the different pathogens recorded the fungi seems have an important role, than in order to distinguish saprophytic or opportunistic species from potential pathogens (including the non cultivable ones) we applied d…
Influence of Bacterial Secondary Symbionts in Sitobion avenae on Its Survival Fitness against Entomopathogenic Fungi, Beauveria bassiana and Metarhiz…
2022
The research was focused on the ability of wheat aphids Sitobion avenae, harboring bacterial secondary symbionts (BSS) Hamiltonella defensa or Regiella insecticola, to withstand exposure to fungal isolates of Beauveria bassiana and Metarhizium brunneum. In comparison to aphids lacking bacterial secondary symbionts, BSS considerably increased the lifespan of wheat aphids exposed to B. bassiana strains (Bb1022, EABb04/01-Tip) and M. brunneum strains (ART 2825 and BIPESCO 5) and also reduced the aphids’ mortality. The wheat aphid clones lacking bacterial secondary symbionts were shown to be particularly vulnerable to M. brunneum strain BIPESCO 5. As opposed to wheat aphids carrying bacterial s…
The Independent Biological Activity of Bacillus thuringiensis Cry23Aa Protein Against Cylas puncticollis
2020
The Cry23Aa/Cry37Aa proteins from Bacillus thuringiensis (Bt) have been described toxic to Cylas puncticollis larvae. In general, it is believed that Cry23Aa and Cry37Aa act jointly to exert the insecticidal activity, while there is no evidence of their toxicity individually. Therefore, in the present study, the contribution of each protein in the insecticidal activity toward C. puncticollis larvae has been assessed. The results showed that both proteins were toxic for C. puncticollis larvae when tested individually. Contrary to what was claimed previously, our results suggest that the presence of both proteins is not necessary to exert toxicity against C. puncticollis larvae. Also, the bin…
Community Composition, Antifungal Activity and Chemical Analyses of Ant-Derived Actinobacteria
2020
Actinobacteria associated with insects represent one potentially rich source of novel natural products with antifungal activity. Here, we investigated the phylogenetic diversity and community composition of actinobacteria associated with ants using a combination of culture-dependent and -independent methods. Further, we assessed the antagonistic activity against phytopathogenic fungi and identified the secondary metabolites from isolates with bioactivity. A total of 416 actinobacterial isolates were obtained from three ant species (Camponotus japonicus, Lasius fuliginosus, and Lasius flavus) located in five nests. The largest amount of isolates were observed in the head samples. 16S rRNA ge…
The microbiology of Lascaux Cave.
2010
Lascaux Cave (Montignac, France) contains paintings from the Upper Paleolithic period. Shortly after its discovery in 1940, the cave was seriously disturbed by major destructive interventions. In 1963, the cave was closed due to algal growth on the walls. In 2001, the ceiling, walls and sediments were colonized by the fungus Fusarium solani. Later, black stains, probably of fungal origin, appeared on the walls. Biocide treatments, including quaternary ammonium derivatives, were extensively applied for a few years, and have been in use again since January 2008. The microbial communities in Lascaux Cave were shown to be composed of human-pathogenic bacteria and entomopathogenic fungi, the for…
Degradation of Amino-(3-methoxyphenyl)methanephosphonic Acid by Alternaria sp
2002
Alternaria sp. isolated from the surface of carrot ( Daucus carota ) seeds appeared to be able to degrade amino-(4-methoxyphenyl)-methanephosphonic acid using it as a sole source of carbon, nitrogen, and phosphorus for growth.