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Flow approaches in agri-food systems research: revealing blind spots to support social-ecological transformation
No full textInternational audienceAgrifood systems are called upon to undergo profound transformation. The development of “flow approaches” (including lifecycle assessment, carbon footprint, ecological footprint, and metabolism methodologies) has been crucial to point to the material side of human activities. More specifically, these approaches highlight the material and energetic costs of long agrifood value-chains, intensive farming practices, high levels of geographic specialization, as well as the production of non-food commodities. In the logical progression from diagnosis to action, flow approaches are currently being used as decision-support tools. But what are the biases induced by flow approaches when it comes to supporting real-world transformations? Based on our experience and interdisciplinary background, we argue that flow approaches provide a decontextualized and narrow framing of issues related to agrifood systems, such as accumulations and transfers across space and time, inequalities and asymmetries along the chain of activities, or long-lasting environmental impacts. Some aspects are measured and emphasized, while others are difficult to observe or neglected. Flow approaches, alone, are not well suited to inform issues of environmental justice, radical transformation, and local governance. As in most cases methodological advances will not suffice to overcome the biases induced; we call for hybridizing methods and for broadening analytical perspectives
Assessment of the impact of pasteurisation on protein denaturation in sheep sweet whey by asymmetrical flow field-flow fractionation according to sampling period
No full textInternational audienceWhey recovery is limited in artisanal cheese manufacture. This by-product of cheese manufacture was traditionally considered as waste and is highly polluting. However, interest in the nutritional properties of native whey and its proteins has recently increased. Pretreatment is required to preserve highly perishable whey for processing. Only a few studies have focused on sheep whey, despite its considerable nutritional and technological potential. Here, we investigated the effect of heat treatment on the denaturation and formation of protein aggregates in sweet sheep whey collected in January, April and July. Two pasteurisation protocols were studied (72 • C for 1 min and 80 • C for 15 s). Microbiological quality was assessed by checking for the presence of microbes after five days of storage at 4 • C. Asymmetrical flow field-flow fractionation (AF4) coupled to UV detector, multiangle light scattering (MALS) and refractometer (dRi) is a mild, non-naturing technique for determining the extent of denaturation of whey proteins and the size of whey protein aggregates. Greater whey protein denaturation and larger whey protein aggregates were observed for the 80 • C/15 s protocol than for the 72 • C/1 min protocol, for the January and April samples. A decrease in Immunoglobulin G (IgG) content was observed after heat treatments in the samples from July but not significantly for the other proteins. Moreover, the retention times of the monomeric whey protein peaks on the AF4 fractogram were higher for this period, indicating that the proteins were larger. Microbiological testing showed that both pasteurisation treatments were sufficiently effective to ensure good sanitary quality. The pasteurisation schedule best preserving native proteins was heating at 72 • C for 1 min
Contrasting patterns of differentiation among three taxa of the rapidly diversifying orchid genus Ophrys sect. Insectifera (Orchidaceae) where their ranges overlap
No full textInternational audienceIn rapidly diversifying groups, taxa defined on the basis of typological criteria can be difficult to support with genetic data. The diversity observed in the insect-mimicking orchid genus Ophrys perfectly illustrates this situation; among 400 described species only 9–10 lineages are detectable by genetic markers such as nrITS. The three taxa described in the Ophrys insectifera group, O. insectifera, O. subinsectifera, and O. aymoninii, can be clearly distinguished by their flowers, which have evolved different phenotypes as a result of adaptation to specific pollinator insect species from three different families. However, genetic differentiation between these three taxa has never been really supported by population genetic data and their taxonomic status is still debated. Using population genomic approaches, we found a clustering consistent with the existence of three genetic entities where the geographic distributions of the three taxa overlap. Two of these clusters correspond to France populations of the widespread O. insectifera and the micro-endemic O. aymoninii. However, the last cluster grouped together all the Iberian individuals, suggesting that individuals phenotypically identified as either O. insectifera or O. subinsectifera are genetically weakly differentiated there. Populations of the two pairs of taxa thus may have experienced different patterns of inter-specific gene flow
A form of organisational innovation in agricultural enterprises and its impact on the greening of practices: the case of collective farms
No full textThis issue deals with organizational innovations for the agroecological transition and sustainable agri-food systems, which took place in March 2024 at VetAgro Sup in Lempdes.International audienceA number of conditions are required for organizational innovation in agricultural enterprises. Using the example of a recently-established collective farm, the text explores the various organizational innovations that have been introduced to promote the sustainability of the agri-food system
Time-resolved transcriptomics of single Vitis vinifera fruits: membrane transporters as switches of the double sigmoidal growth
No full textData Availability: All raw transcriptomic reads have been deposited in the NCBI Sequence Read Archive (http://www.ncbi.nlm.nih.gov/sra). The BioProject is PRJNA862686.International audienceGrape berries lose one H+ per accumulated sucrose at the inception of ripening, but the molecular mechanisms associated with this remain unknown. By investigating single fruits, we elucidated the fundamentals of the malate-sugar nexus, previously obscured by asynchrony in population-based models of ripening. The development of individual fruits was explored to capture simultaneous changes in gene expression and metabolic fluxes from flowering to overripening. Dynamics in water, tartrate, malate, hexoses, and K+ fluxes obtained by combining individual single fruit growth and concentration data, allowed us to define eleven sub-phases in fruit development, with defined groups according to RNA sequencing analysis. Co-expression network analysis revealed a range of transcript level-metabolic rate associations. A set of membrane transporters related to vacuolar over-acidification was found specifically expressed during the first growth phase. Unlike in slightly more acidic citrus, vacuolar H+-pyrophosphatase transcripts were predominantly expressed, followed by vacuolar ATPase, clarifying a thermodynamic limit beyond which their replacement by the tonoplast P3A/P3B ATPase complex is essential. Unexpectedly, expression of aluminium-activated malate transporter was low at this stage, possibly replaced by an uncharacterized anion channel. At the onset of ripening, the role of hexose transporter HT6 as a molecular switch in sugar accumulation was confirmed, electroneutralized by malate vacuolar leakage and H+ pumps activation
Unravelling the impact of domestication on competitive ability in durum wheat: a phenotypic plasticity perspective
No full textThe data to reproduce all analyses of this paper are available at Dryad digital repository: https://doi.org/10.5061/dryad.t1g1jwtbk (Lemoine et al., 2025).International audienceThe need to address the impact of domestication on plant traits is frequently highlighted in modern agriculture. It is often argued that domesticated plants have lost competitive ability due to reduced phenotypic plasticity. This study investigates whether domestication has affected competitive ability, functional trait values, and plasticity in durum wheat across 39 genotypes representing four key stages of domestication, from wild progenitors to modern elite varieties. Plants were grown in pots, both alone and in competition with the same neighbouring genotype. Biomass, and above- and belowground traits were measured at the end of the vegetative stage. Our results showed that the three domesticated groups lost less biomass in response to competition compared with their wild progenitors. All genotypes developed thinner leaves and thicker roots when grown with a neighbour. While wild progenitors exhibited the highest plasticity, this did not translate to a greater competitive ability. These findings challenge the theoretical expectation that domesticated plants are less suited for competition. Instead, they suggest that domesticated plants perform well in competitive environments and question the need to reintroduce wild traits to improve competitive ability
Phytostabilisation d'un site minier : étude de faisabilité : application au site du bois vert
No full textInternational audienceLes éléments traces métalliques (ETMs) dans les sols constituent une préoccupation majeure en raison des risques potentiels pour la santé humaine et les écosystèmes. Des approches impliquant la phytostabilisation ont donné des résultats intéressants pour limiter le transfert des ETMs par érosion hydrique et éolienne. Sur les anciens sites miniers, garantir l'atteinte des performances (taux de couvert végétal, limitation des flux solides, etc.) peut être difficile en raison non seulement des concentrations élevées en polluants métalliques mais également à cause de la faible fertilité du substrat. Chaque site étant un cas particulier, le recourt à la phytostabilisation doit être raisonné et adapté aux contraintes particulières du site à traiter. Pour valider le recours à la phytostabilisation, des essais de faisabilité sont communément réalisés.Cette étude présente les résultats de l'étude de faisabilité menée sur 2 zones de l'ancien site minier du Bois Vert sur la commune d'Abbaretz (44) pour valider la faisabilité du recours à cette technique et pour définir la meilleure approche de phytostabilisation en vue de gérer les transferts par érosion. Cette étude de faisabilité a intégré des essais en pots au laboratoire et des essais sur site.Au final, après 3 ans, les essais sur site ont montré que la phytostabilisation des deux zones d'études est envisageable. Le suivi des parcelles a permis de sélectionner les espèces végétales (ligneux et herbacées) pour chaque zone et de mettre en évidence des points d'attention opérationnels pour une mise en oeuvre à grande échelle.</div
The lesser yam Dioscorea esculenta (Lour.) Burkill: a neglected crop with high functional food potential
No full textInternational audienceIn the humid tropical zone, there is a growing need for staple crops diversification and for alternatives to cereals. The lesser yam (Dioscorea esculenta (Lour.) Burkill), also known as the Asiatic yam, presents the highest agro-economic potential among the minor yam species. Here, we clarify the taxonomy and review research on the phylogeny, cytology, germplasm characterization and conservation, in vitro culture, virology, agronomy and nutritional composition of D. esculenta. The species is genetically distant from all the other cultivated yams and is the sole representative of the section Combilium. Diploids (2n = 40), triploids (60) and tetraploids (80) exist but higher number of chromosomes are also reported. Except in India, Vietnam and the Philippines, very few accessions are preserved in ex situ collections. In vitro preservation is feasible and the percentage of surviving cultures of D. esculenta is not significantly different to major yam species. The crop is free of major pests and diseases compared to other cultivated yams and if 13 viruses have been detected, their incidence is asymptomatic. When plants are staked, yields of 30-40 t/ha are frequent. The attractive shape of its small tubers and its extremely thin skin are assets for urban consumers. They are rich in secondary metabolites including phenols, flavonoids, allantoin, inulin and saponins with well documented physiological properties. The lesser yam has potential as a high valued functional food. Surprisingly, no DNA marker research has been conducted to assess the allelic diversity of the species and there are no breeding activities to strengthen its potential. Future research directions are discussed
Potential shortfalls of using entomopathogenic fungi for boosting the sterile insect technique to control the oriental fruit fly, Bactrocera dorsalis
No full textInternational audienceEntomovectoring relies on the dissemination of biocides by insects to control plant pests and diseases. Current research aims at coupling entomovectoring with the Sterile Insect Technique (SIT). Such boosted-SIT is a promising technique to control the Oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera, Tephritidae), an invasive pest that dooms African and Asian fruit-producers and is invading Europe. Here, we investigated empirically the potential of boosting the SIT using spores of the entomopathogenic fungus, Metarhizium anisopliae. Laboratory bioassay confirmed the transmission potential of the fungus from inoculated males to males and females, with subsequent reductions in survival and fecundity. Inoculation, like sterility, nonetheless reduced male mating success. Semi-field tests (i.e., large outdoor cages) revealed greater costs of fungal inoculation on male competitivity than observed in the laboratory. Combined with effects of inoculation on male survival, these costs led to a lower reduction in female reproduction in the presence of inoculated sterile males compared to plain sterile males. As tested here, boosting the SIT with M. anisoplae spores to control B. dorsalis could reduce its efficacy. The encouraging transmission patterns, however, suggest that technical improvements may render the boosted-SIT effective in some, if not all, ecological contexts
Testing fraternal birth order effects and antagonistic effects for homosexual men: power comparison of various methods
No full textInternational audienceResearch on the biological determinants of male homosexual preference has long realized that the older brother effect (FBOE, i.e., a higher fraternal birth rank of homosexuals) and the antagonist effect (AE, i.e., more fertile women have a higher chance of having a homosexual son) can both generate family data where homosexual men have more siblings and more older siblings than heterosexual men. Various statistical approaches were proposed in the recent literature to evaluate whether the action of FBOE or AE could be discriminated from empirical data, by controlling for the other effect. Here, we used simulated data to formally compare all the approaches that we could find in the relevant literature for their ability to reject the null hypothesis in the presence of a specified alternative hypothesis (tests based on regression, Bayesian modeling, or contingency tables). When testing for the FBOE, the relative performance of the different tests was different depending on the specific function generating the older brother effect. Even if no tests were found to always perform better than the others, some tests performed systematically poorly, and some tests displayed a systematic high rate of type-I error. For testing the AE, the relative performance of the tests was generally not changed across all parameter values assayed, providing a clear ranking of the various proposed approaches. Pros and cons for each candidate test are discussed, taking into consideration power and the rate of type-I error but also practicability, the possibility to control for confounding variables, and to consider alternative hypotheses