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Travailler dans les exploitations agricoles en France métropolitaine : faire-faire aux autres en s’entourant de salariés
No full textdoi : 10.17180/3bky-44saLa carte présentée ici a été élaborée dans le cadre d’un travail de recherche visant à construire une géographie du faire et du faire-faire dans les exploitations agricoles en France Métropolitaine. Cette typologie départementale est le résultat d’une classification automatique hiérarchisée (CAH) mobilisant différentes données statistiques étalonnées de 1852 à 2024 (Enquêtes agricoles de 1852, 1892, 1929 ; recensements agricoles de 1955, 1979, 1988, 2000, 2010, 2020 et des données de la MSA de 2002 à 2024). Six cartes ont été réalisées de façon à visualiser les différentes formes du travail dans les exploitations agricoles. Elles constituent un matériel complémentaire à l'article publié dans la revue Pouvoirs en avril 2026.Cette carte a été réalisée grâce à la collaboration entre Lucette Laurens (INRAE-ACT-UMR Innovation et université Montpellier-Paul Valéry) et Jean-Philippe Cherel, (LAGAM, université Montpellier-Paul Valéry)
Routine LC-MS/MS method for quantifying Alternaria toxins in tomatoes at harvest stage and during processing
No full textInternational audienceA high-performance liquid chromatography tandem mass spectrometry method has been developed and validated to quantify alternariol, alternariol monomethyl ether, tenuazonic acid, altenuene, altertoxin I, and tentoxin, and implemented to better understand the risks associated with Alternaria contamination of tomatoes and fate of the toxins during processing. This method has been developed for routine use, by reducing the cost, duration, and complexity of manipulations. Limits of quantification were below EU recommendations 2022/553, reaching 1.2-3.7 µg kg-1 for alternariol and alternariol monomethyl ether and 9.4-18.4 µg kg-1 for tenuazonic acid depending on the matrix. Apparent recovery ranged between 85 and 103%, and intraday repeatability was <15%. Different Alternaria strains isolated from tomatoes were assessed for their toxin production profiles, and the impact of processing operations on Alternaria toxins naturally occurring in tomatoes was evaluated on a pilot scale. Tenuazonic acid was the predominant toxin produced by Alternaria strains and contaminating tomatoes. Processing operations did not reduce toxin accumulation, which demonstrates its thermostability. Additionally, tomato skin and seeds residues, which are reused for different applications, was 2.6 times more contaminated than tomato pulp
Local trade-offs shape flower size evolution across Arabidopsis thaliana distribution
No full textThe diversification of flowers, largely driven by mutualistic interactions with animal pollinators, has generated remarkable variation in floral form and size and is thought to have driven the evolutionary radiation of angiosperms. Here, we investigate the geographic variation in reproductive organ growth in the self-fertilizing species Arabidopsis thaliana , where the loss of pollinator dependence is predicted to favour reduced floral investment through resource reallocation. We find extensive variation in flower size underpinned by a polygenic architecture, in which derived alleles both increase and decrease petal size and show signatures of positive selection. The direction of flower-size evolution varies geographically, reflecting environmentally mediated shifts in the relationship between flower size and seed production. Strong purifying selection at the species’ climatic margins favors smaller flowers, whereas relaxed environmental constraints in more suitable habitats allow the persistence and potential adaptive value of large-flower variants. This biogeographic pattern extends to other life-history traits, illustrating how environmental heterogeneity, acting through resource allocation constraints, shapes evolutionary trajectories and maintains phenotypic diversity in selfing lineages
From individual to stand performance in hybrids: challenging the optimal parental genetic distance
No full textInternational audienceHybridization, the interbreeding of distinct genotypes, drives evolutionary processes like speciation and adaptation, potentially via phenotypic transgression, where hybrids exhibit novel traits. In crop breeding, research has largely focused on optimizing heterosis to enhance hybrid performance, particularly for traits such as biomass. It is only recently that the ecological implications of hybridization have been considered, highlighting hybridization as a biotic interaction occurring within populations and communities. This shift raises fundamental questions about whether hybrid performance shows consistent patterns across individual and population scales, particularly regarding predictions based on parental genetic distance. Here, we address this question by examining Arabidopsis thaliana F2 hybrids across a wide range of genetic distances, to compare hybrid performance at individual and stand levels. Our results reveal scale-dependent patterns: individual performance peaks at intermediate parental genetic distances, while stand-level performance increases with genetic divergence, particularly in hybrids between relict and non-relict lineages. These results underscore the importance of scale when evaluating hybrid performance, as plant-plant interactions at the group level can alter the collective outcomes of individual performance. Finally, this framework underscores the importance of integrating individual and population perspectives to better understand the outcomes and potential applications of hybridization
Plant identity and environmental filtering are the key drivers of bacterial community structure in four desert plant species from the Sahara Desert in Morocco
No full textData availability: The datasets generated and analyzed during the current study are available in the NCBI SRA repository under BioProject accession number PRJNA1291135 and will be made publicly available upon publication.International audienceBackground: Plant microbiome is a very wide research area playing a major role in agriculture and plant health. This study investigates the interactions between root-associated bacterial communities and soil physico-chemical characteristics of four Moroccan desert plant species: Lavandula coronopifolia Poir. (n = 20), Lycium intricatum Boiss. (n = 20), Nitraria retusa Asch. (n = 20) and Searsia tripartita (Ucria) Moffett. (n = 20). Soil samples were collected in the rhizosphere of each plant species, and root samples from four different sites, with five random samples per site. Elemental chemical composition of soil sample was analyzed using the X-Ray fluorescence spectrometry and soil carbon, i.e., organic carbon (SOC) and inorganic carbon (SIC) were measured using the Rock-Eval® Oxypure method. Roots were assessed for their microbial community, using the 16S rDNA metabarcoding analysis.Results: Significant variation in soil parameters was observed across sites and among the four desert plant species. SOC and SIC contents were highest in soils associated with S. tripartita, N. retusa, and Ly. intricatum, while La. coronopifolia was associated with elevated levels of Si, Al, K, and Mn. Soil EC was highest in N. retusa and S. tripartita. Microbial analysis revealed that Pseudomonadota and Actinomycetota dominated the root-associated bacterial communities, comprising around 60% of total abundance. Alpha diversity (Shannon and Simpson indices) varied significantly across species and sites, especially in La. coronopifolia. Beta diversity analyzes confirmed that geographic location significantly influenced microbial community structure. Rhizosphere network complexity and composition varied by species, with N. retusa showing broad ecological tolerance, while S. tripartita communities were strongly shaped by SOC, SIC, K, Ca, Mn, and Fe. Mantel test results further highlighted that plant identity and environmental factors differentially influence root microbial composition across sites.Conclusion: Each plant species showed unique responses in terms of soil characteristics and microbial communities, highlighting the importance of adopting a species-specific approach
A large-scale study across the avian clade identifies ecological drivers of neophobia
No full textInternational audienceNeophobia, or aversion to novelty, is important for adaptability and survival as it influences the ways in which animals navigate risk and interact with their environments. Across individuals, species and other taxonomic levels, neophobia is known to vary considerably, but our understanding of the wider ecological drivers of neophobia is hampered by a lack of comparative multispecies studies using standardized methods. Here, we utilized the ManyBirds Project, a Big Team Science large-scale collaborative open science framework, to pool efforts and resources of 129 collaborators at 77 institutions from 24 countries worldwide across six continents. We examined both difference scores (between novel object test and control conditions) and raw data of latency to touch familiar food in the presence (test) and absence (control) of a novel object among 1,439 subjects from 136 bird species across 25 taxonomic orders incorporating lab, field, and zoo sites. We first demonstrated that consistent differences in neophobia existed among individuals, among species, and among other taxonomic levels in our dataset, rejecting the null hypothesis that neophobia is highly plastic at all taxonomic levels with no evidence for evolutionary divergence. We then tested for effects of ecological factors on neophobia, including diet, sociality, habitat, and range, while accounting for phylogeny. We found that (i) species with more specialist diets were more neophobic than those with more generalist diets, providing support for the Neophobia Threshold Hypothesis; (ii) migratory species were also more neophobic than nonmigratory species, which supports the Dangerous Niche Hypothesis. Our study shows that the evolution of avian neophobia has been shaped by ecological drivers and demonstrates the potential of Big Team Science to advance our understanding of animal behavior
Analyser les inégalités d’accès à l’alimentation au prisme des paysages alimentaires
No full textNational audienceFace aux enjeux sociaux, environnementaux et de santé liés aux comportements alimentaires, différents groupes d’experts à l'instar du HLPE préconisent d’agir sur l'environnement alimentaire pour favoriser des pratiques alimentaires plus saines. Pour autant, que sait-on des relations entre environnements et comportements alimentaires ? Comment les pouvoirs publics peuvent agir ? L'étude des paysages alimentaires, c'est-à-dire à la fois de l'environnement alimentaire (localisation des commerces, prix, publicité, etc.) et de la manière dont celui-ci est perçu et vécu par les habitants permet de révéler des inégalités socio-spatiales d'accès à l'alimentation. A partir de recherche conduites principalement à Montpellier, nous montrons le potentiel d'une telle approche, tant pour produire des connaissances scientifiques que pour accompagner des collectivités souhaitant développer une politique visant à réduire ces inégalités
Adaptation of the Cyst Nematode Globodera pallida to the Colinear Potato Resistant QTLs GpaVvrn and GpaVspl Involved Distinct Genomic Regions and Absence of Cross-Virulence
No full textInternational audienceThe use of alternative methods to control cyst nematode populations has accelerated since the ban of chemical nematicides in Europe. The resistant QTL GpaVvrn, derived from the wild species Solanum vernei, is widely present in resistant European potato cultivars and provides strong protection against Globodera pallida populations although a risk of resistance breakdown has already been demonstrated in both experimental evolution studies and field populations. The wild relative S. sparsipilum, harbouring the resistant QTL GpaVspl, would be an interesting alternative source of resistance to control virulent G. pallida. The goal of the present study was to understand the genomics of adaptation of the nematode to these two colinear resistant QTLs. Starting with two natural populations, an experimental evolution approach allowed, after 10 generations on resistant potato genotypes, selecting independent nematode lineages adapted to each QTL. These virulent lineages were analysed through a combination of phenotyping and genome scans approaches. Phenotyping enabled the quantification of virulence levels and confirmed resistance breakdowns. Pool‐Seq whole genome sequencing followed by genome scan analyses identified genomic regions under selection, potentially involved in the adaptive mechanisms to each resistance factor. Candidate genes within these regions provided insights into the genetic basis of adaptation, revealing effectors known to suppress plant immunity. As genome scans highlighted distinct genomic regions for the adaptation to both resistant factors, we were able to predict and phenotypically confirm the absence of cross‐virulence between nematode lineages evolving on GpaVvrn and GpaVspl. These findings have significant implications for the design of effective and sustainable resistance management strategies
Insect-habitat-plant interaction networks provide guidelines to mitigate the risk of transmission of Xylella fastidiosa to grapevine in Southern France
No full textInternational audienceXylella fastidiosa (Xf) is a xylem-limited bacterium that has been recorded in several European countries since its detection in 2013 in Apulia (Italy). Given the prominence of the wine industry in many southern European countries, a big threat is the development of Pierce's disease in grapevines. Yet, the insect-habitat and insect-plant interaction networks in which xylem feeders, possible vectors of Xf, are involved around European vineyards are largely unknown. Here we describe these networks in three key wine-growing regions of southern France (Provence-Alpes-Côte d'Azur, Occitanie, Nouvelle-Aquitaine) to identify primary xylem feeder habitats, and assess their specialization degree at the habitat, plant family, and plant species levels. A total of 92 landscapes (and 700 sites) were studied over three sampling sessions in the fall 2020, spring 2021, and fall 2021. Among the habitats sampled, meadows hosted the largest xylem feeder communities, followed by alfalfa fields. Vineyard headlands and inter-rows hosted slightly smaller xylem feeder communities, indicating that potential Xf vectors thrive near crops. Grapevines hosted few xylem feeders, suggesting rare but possible transfer to vulnerable crops. Philaenus spumarius, Aphrophora alni, Lepyronia coleoptrata, and Cicadella viridis were all similarly generalists at the habitat, plant family or plant species level. The only specialist was Aphrophora grp. salicina, which was restricted to riparian forests and to Salicaceae. Neophilaenus spp. were extremely specialist at the plant family level (Poaceae), but rather generalist at the habitat and plant species levels. All 1017 insects screened for the presence of Xf tested negative, showing that Xf is not widespread in the studied regions. Our study provides new basic ecological information on potential vectors of Xf, especially on their specialization and feeding preferences, as well as practical information that may be relevant for the design of epidemiological surveillance plans.<p
Proteomic-based prediction of functional bioactive peptides in proteins extracted from Torreya grandis using choline chloride-based deep eutectic solvents
No full textSource Agritrop Cirad (https://agritrop.cirad.fr/615512/)International audienceFive deep eutectic solvents were used to extract T. grandis nut protein, with water as comparison. ChCl:Urea was the most effective, preserving integrity and functionality of extracted proteins. Cold ethanol purification yielded highest protein recovery rate 6.89 % ± 0.12 %. Time, temperature, and solid-liquid ratio, were optimized using response surface methodology and a Box-Behnken design. Extracted proteins were characterized via SDS-PAGE to assess digestibility and functional properties. Proteins extracted by DES were further analyzed via LC-MS/MS. De novo sequencing identified 600 peptides with 235 proteins in DES extract, compared to 349 peptides and 143 proteins in the water extract. Furthermore, 87 functional oligopeptides in DES, compared to 41 in water. DES extract contain 63 antioxidant peptides, with three distinct peptides GGE, CME, and YIY. CME peptide had highest antioxidant activity. These findings highlighted DES for extracting smaller functional proteins and peptides from T. grandis, demonstrating potential in food industry applications for protein extraction