Search results for "vulpin"

Blackgrass (Alopecurus myosuroides Huds.) seed dispersal from a single plant and its consequences on weed infestation

2001

Blackgrass (Alopecurus myosuroides Huds.) seed dispersal from single mother-plants was studied in two experiments. For the first experiment, eight blackgrass plants of different heights and number of ears were produced in a greenhouse with the help of different in sowing densities and nitrogen nutrition levels. At the beginning of seed shedding, the plants were placed outside, and seeds were gathered daily. Daily seed dispersal was analysed by fitting a Weibull equation to the number of seeds as a function of distance to the mother-plant. The second experiment was carried out in a field comprising winter barley and spring barley plots as well as bare soil. In each of these three parts, two …

Nucleotide Variability at the Acetyl Coenzyme A Carboxylase Gene and the Signature of Herbicide Selection in the Grass Weed Alopecurus myosuroides (H…

2004

Acetyl coenzyme A carboxylase (ACCase) is the target of highly effective herbicides. We investigated the nucleotide variability of the ACCase gene in a sample of 18 black-grass (Alopecurus myosuroides [Huds.]) populations to search for the signature of herbicide selection. Sequencing 3,396 bp encompassing ACCase herbicide-binding domain in 86 individuals revealed 92 polymorphisms, which formed 72 haplotypes. The ratio of nonsynonymous versus synonymous substitutions was very low, in agreement with ACCase being a vital metabolic enzyme. Within black grass, most nonsynonymous substitutions were related to resistance to ACCase-inhibiting herbicides. Differentiation between populations was stro…

SNP markers for black-grass (Alopecurus myosuroides Huds.) genotypes resistant to Acetyl CoA-carboxylase inhibiting herbicides

2002

Chloroplastic acetyl CoA-carboxylase (ACCase) is the target of widely used, specific graminicide herbicides: cyclohexanediones (CHDs) and aryloxyphenoxypropionates (APPs). Resistance to these compounds is a worldwide, increasing problem. Population genetic studies aimed at understanding the dynamics of this situation and the diffusion of resistance genes within and between weed populations are challenging because biological assays are not adequate for this purpose, and because different mechanisms of resistance confer a similar resistance phenotype. Molecular markers for specifically detecting resistance genes are therefore urgently needed to conduct such studies. For this purpose, we clone…

Molecular Bases for Sensitivity to Acetyl-Coenzyme A Carboxylase Inhibitors in Black-Grass

2005

Abstract In grasses, residues homologous to residues Ile-1,781 and Ile-2,041 in the carboxyl-transferase (CT) domain of the chloroplastic acetyl-coenzyme A (CoA) carboxylase (ACCase) from the grass weed black-grass (Alopecurus myosuroides [Huds.]) are critical determinants for sensitivity to two classes of ACCase inhibitors, aryloxyphenoxypropionates (APPs) and cyclohexanediones. Using natural mutants of black-grass, we demonstrated through a molecular, biological, and biochemical approach that residues Trp-2,027, Asp-2,078, and Gly-2,096 are also involved in sensitivity to ACCase inhibitors. In addition, residues Trp-2,027 and Asp-2,078 are very likely involved in CT activity. Using three-…

An isoleucine residue within the carboxyl-transferase domain of multidomain acetyl-coenzyme A carboxylase is a major determinant of sensitivity to ar…

2003

Abstract A 3,300-bp DNA fragment encoding the carboxyl-transferase domain of the multidomain, chloroplastic acetyl-coenzyme A carboxylase (ACCase) was sequenced in aryloxyphenoxypropionate (APP)-resistant and -sensitive Alopecurus myosuroides (Huds.). No resistant plant contained an Ile-1,781-Leu substitution, previously shown to confer resistance to APPs and cyclohexanediones (CHDs). Instead, an Ile-2,041-Asn substitution was found in resistant plants. Phylogenetic analysis of the sequences revealed that Asn-2,041 ACCase alleles derived from several distinct origins. Allele-specific polymerase chain reaction associated the presence of Asn-2,041 with seedling resistance to APPs but not to C…

Effects of seed production and storage conditions on blackgrass (Alopecurus myosuroides) germination and shoot elongation

2003

Abstract Blackgrass is a common winter annual grass weed in autumn-sown crop rotations in Atlantic European countries. Control with a minimum amount of herbicides in integrated cropping systems would be facilitated by modeling the effect of cropping systems on its demography. To develop the submodel relating weed seed bank to emerged seedlings, laboratory experiments were conducted to analyze and quantify seed germination and shoot elongation. These processes were studied as a function of environmental conditions during seed production (nitrogen availability, water deficit, plant density, and crop) and of seed characteristics (seed weight, harvest date, storage length, and dry-stored/soil-b…

Long-term modelling of weed control strategies: analysis of threshold-based options for weed species with contrasted competitive abilities

2002

A simple life-cycle-based demography model was adapted for two contrasting weed species (Alopecurus myosuroides and Poa annual. This model included a seed production function that accounted for population self-regulation through weed:weed interactions. The A. myosuroides version of the model was tested with field data. Long-term simulations of population demography were then performed to investigate the relationship between weed control strategies based on density thresholds and both the frequency of herbicide use and the long-term economic profitability. This study confirms that threshold-based weed management strategies are more cost-effective than spraying every year and may allow import…

Effect of vernalization on the development and growth of Alopecurus myosuroides

2002

Alopecurus myosuroides is an annual winter grass weed present in many winter and spring crops. The vernalization responses of three populations of A. myosuroides were assessed using natural exposure during winter in two field experiments and using cold exposure of imbibed seeds in a refrigerator in two greenhouse experiments. It was observed that a period of chilling during the pregermination phase had a marked effect on subsequent phenology. In the greenhouse, the major effect of vernalization was the reduction in the vegetative period because of an early reproductive induction of the apex. Plant morphology was affected by vernalization via a decrease in biomass resulting from a reduced ti…

Study of the growth of herbicide-resistant black-grass populations

1991

International audience

Aligot d'estepa, Ratonero de las estepas (VER0000134)

Altres noms vulgars: Common Buzzard (Western Steppe) (Anglès), Buse variable (vulpinus) (Francès), Mäusebussard-vulpinus (Alemany) Gabinet de Vertebrats (Departament de Zoologia), Facultat de Ciències Biològiques (Campus de Burjassot), C/ Doctor Moliner, s/n, Bloque B. 5é plant, Burjassot (Valencia). Armari: 1-2