Search results for "pest"
showing 10 items of 1124 documents
Evaluating Resistance to Bt Toxin Cry1Ab by F<SUB>2</SUB> Screen in European Populations of Ostrinia nubilalis (Lepidoptera: Crambidae)
2010
ABSTRACT The large-scale cultivation of transgenic crops producing Bacillus thuringiensis (Bt) toxins have already lead to the evolution of Bt resistance in some pest populations targeted by these crops. We used the F2 screening method for further estimating the frequency of resistance alleles of the European corn borer, Ostrinia nubilalis (Hubner) (Lepidoptera: Crambidae), to Bt maize, Zea mays L., producing the CrylAb toxin. In France, Germany, and Italy, 784, 455, and 80 lines of European corn borer were screened for resistance to Mon810 maize, respectively. In Slovakia, 26 lines were screened for resistance to the CrylAb toxin. The cost of F2 screen performed in the four countries varie…
Biological control of plant diseases
2000
The present chapter reviews the question of developing a microbial control method of plant diseases. All problems which may occur, from the initial screening of an efficient biocontrol agent to the final step of integration of the biological control method into the crop management system are briefly examined.
Outside-host predation as a biological control against an environmental opportunist disease
2017
Abstract Environmentally growing opportunist pathogens are a common threat to human health and food production. Due to environmental growth of the pathogen, these diseases are difficult to control with disinfectants and antibiotics. Thus, there is a need for sustainable and effective control methods against environmentally growing opportunist diseases. Predation is often a major limiting factor in the outside host environment. Here we propose that it could be used in the biological control of these diseases. We introduce a novel epidemiological model for environmentally growing opportunists combining pathogen growth within-host (SI model) and outside-host into classical predator-prey model.…
2,4-D impact on bacterial communities, and the activity and genetic potential of 2,4-D degrading communities in soil
2006
The key role of telluric microorganisms in pesticide degradation is well recognized but the possible relationships between the biodiversity of soil microbial communities and their functions still remain poorly documented. If microorganisms influence the fate of pesticides, pesticide application may reciprocally affect soil microorganisms. The objective of our work was to estimate the impact of 2,4-D application on the genetic structure of bacterial communities and the 2,4-D-degrading genetic potential in relation to 2,4-D mineralization. Experiments combined isotope measurements with molecular analyses. The impact of 2,4-D on soil bacterial populations was followed with ribosomal intergenic…
Ecological fitness of the biocontrol agent Fusarium oxysporum Fo47 in soil and its impact on the soil microbial communities
2009
Some nonpathogenic strains of Fusarium oxysporum can control Fusarium diseases responsible for severe damages in many crops. Success of biological control provided by protective strains requires their establishment in the soil. The strain Fo47 has proved its efficacy under experimental conditions, but its ecological fitness has not been carefully studied. In a series of microcosm studies, the ability of a benomyl-resistant mutant Fo47b10 to establish in two different soils was demonstrated. One year after its introduction at two concentrations in the disinfected soils, the biocontrol agent (BCA) established at similar high population densities, whereas in the nondisinfected soils it survive…
The transposable element-rich genome of the cereal pest Sitophilus oryzae
2021
AbstractBackgroundThe rice weevil Sitophilus oryzae is one of the most important agricultural pests, causing extensive damage to cereal in fields and to stored grains. S. oryzae has an intracellular symbiotic relationship (endosymbiosis) with the Gram-negative bacterium Sodalis pierantonius and is a valuable model to decipher host-symbiont molecular interactions.ResultsWe sequenced the Sitophilus oryzae genome using a combination of short and long reads to produce the best assembly for a Curculionidae species to date. We show that S. oryzae has undergone successive bursts of transposable element (TE) amplification, representing 72% of the genome. In addition, we show that many TE families a…
Diuron mineralisation in a Mediterranean vineyard soil: impact of moisture content and temperature
2010
BACKGROUND: The diuron-mineralising ability of the microbiota of a Mediterranean vineyard soil exposed each year to this herbicide was measured. The impact of soil moisture and temperature on this microbial activity was assessed. RESULTS: The soil microbiota was shown to mineralise diuron. This mineralising activity was positively correlated with soil moisture content, being negligible at 5% and more than 30% at 20% soil moisture content. According to a double Gaussian model applied to fit the dataset, the optimum temperature/soil moisture conditions were 27.9 °C/19.3% for maximum mineralisation rate and 21.9 °C/18.3% for maximum percentage mineralisation. The impact of temperature and soil…
Evidence for 2,4-D mineralisation in Mediterranean soils: impact of moisture content and temperature
2009
BACKGROUND: The 2,4-D degradation ability of the microbiota of three arable Mediterranean soils was estimated. The impact of soil moisture and temperature on 2,4-D degradation was investigated. RESULTS: The microbiota of the three soils regularly exposed to 2,4-D were able rapidly to mineralise this herbicide. The half-life of 2,4-D ranged from 8 to 30 days, and maximum mineralisation of 14C-2,4-D ranged from 57 to 71%. Extractable 14C-2,4-D and 14C-bound residues accounted for less than 1 and 15% respectively of the 14C-2,4-D initially added. The highest amounts of 14C-2,4-D bound residues were recorded in the soil with the lowest 2,4-D-mineralising ability. Although all three soils were a…
Contribución al estudio de las comunidades vegetales del orden Potentilletalia caulescentis en la Península Ibérica: la alianza Jasionion foliosae
1985
Se ha efectuado un estudio de la alianza Jasionion foliosae (Asplenietea rupestria) en varios sectores corológicos de la Península Ibérica, describiéndose seis asociaciones de las que tres se proponen como nuevas: Antirrhino pulverulenti-Rhamnetum pumili, Sileno horyii-Saxifragetum cuneatae y Antirrhino granitici-Rhamnetum pumili. A study fon the allince Jasionion foliosae (Asplenietea rupestria) is made in several chorological sectors of the Iberian Peninsula. Six associations are described, of which, three of them are propossed as new: Antirrhino pulverulenti-Rhamnetum pumili, Sileno horyii-Saxifragetum cuneatae and Antirrhino granitici-Rhamnetum pumili. mateo@uv.es