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Multi-stakeholder platforms for enabling agroecological transitions: Configurations and lessons from seven agroecological living landscapes
No full textSource Agritrop Cirad (https://agritrop.cirad.fr/614849/) * Autres projets (id;sigle;titre): ;;(FRA) Initiative on Agroecology//International audienceAgroecological transition (AET) of agrifood systems is a multidimensional process involving diverse stakeholders. Participatory innovation and co-creation of knowledge are also at the heart of agroecology. Deliberately designed Multi-stakeholder platforms (MSPs) are collaborative spaces conducive to driving this type of collaboration and change. However, how these processes are operationalized is poorly documented. This study contributes to filling this gap by highlighting how MSPs can be important vehicles for enabling AETs. As part of the CGIAR Initiative on Agroecology, Agroecological Living Landscapes (ALLs) were set up as MSPs specifically focusing on co-creation of agroecological innovations. By examining different ALL configurations in seven countries, we analyze MSP attributes that can enable and shape AETs at different stages or “levels” of the transition pathway. We find that MSPs can advance different levels of the transition pathway simultaneously by working on multiple innovations involving various stakeholder coalitions. MSPs navigate complex environments, with diverse stakeholders playing multiple policy and non-policy roles to support AETs. The results also illustrate the intersection between MSP configuration and AET objectives, such as policy change, agroecology market support, and scaling adoption. Finally, we discuss the non-linear nature of AET pathways and political economy considerations for stakeholder engagement in MSPs
Topographie : Un facteur clé de la fertilité des sols de reboisement à Madagascar
No full textSource Agritrop Cirad (https://agritrop.cirad.fr/614825/) * Autres projets (id;sigle;titre): ;DIABE;(FRA) Développement Intégré, Aménagement et Bois-Energie//International audienceDescription of the subject. In Madagascar, afforestation plays a significant role in providing wood energy for the local population. However, reforestation projects often face low success rates due to biophysical constraints. Objectives. The aim of this study was to evaluate the impact of topographic position on the physico-chemical properties of potential reforestation sites in the central highlands of Madagascar. Method. The study covered 16 sites and analyzed 192 soil samples. The results were compared with deficiency thresholds established for Ferralsols. Results. The soil pHwater varied slightly, from 5.3 to 5.5. The 0-10 cm depth showed significantly higher levels of organic carbon (Corg), total nitrogen (Ntot), available phosphorus (Pdispo), and exchangeable potassium (Kéch) than the 10-40 cm depth. Soils on the slope were significantly poorer in Ntot and Kéch than those on the bottom of the slope, with mean values of 1,3 g N·kg-1 ± 0,07 and 0,09 cmolc·kg-1 ± 0,01 compared to 1,5 g N·kg-1 ± 0,08 and 0,12 cmolc·kg-1 ±0,01, respectively. Of the 16 sites, eight had to be discarded for future reforestation. Of the remaining eight, only two showed soils with little or no Ntot, Pdispo, and Kéch deficiency over 0-10 cm, but both were deficient in Pdispo. Conclusions. This study highlighted the importance of prior soil characterization, choice of topographic position and recommends starter fertilization for successful reforestation. The results of this study are a contribution to the choice of the most appropriate afforestation sites in Madagascar.Description du sujet. À Madagascar, les reboisements contribuent à l'approvisionnement en bois-énergie de la population. Toutefois, les projets de reboisement sont confrontés à de faibles taux de réussite en raison de contraintes biophysiques. Objectifs. Ce travail vise à évaluer l'impact de la position topographique sur les propriétés physico-chimiques des sols de sites potentiels de reboisement sur les Hautes-Terres Centrales de Madagascar. Méthode. Des prélèvements de sol ont été effectués sur 16 sites non boisés pour un total de 192 échantillons analysés. Les résultats sont comparés à des seuils de carence et de déficience établis pour les sols ferrallitiques. Résultats. Le pHeau des sols varie peu, de 5,3 à 5,5. La profondeur 0-10 cm présente des teneurs significativement plus élevées en carbone organique (Corg), azote total (Ntot), phosphore disponible (Pdispo) et potassium échangeable (Kéch) que la profondeur 10-40 cm. Les sols sur versant sont significativement plus pauvres en Ntot et en Kéch qu'en bas de pente avec des teneurs moyennes de 1,3 g N·kg-1 ± 0,07 et 0,09 cmolc·kg-1 ± 0,01 contre 1,5 g N·kg-1 ± 0,08 et 0,12 cmolc·kg-1 ±0,01, respectivement. Parmi les 16 sites, huit sont à écarter pour de futurs reboisements. Parmi les huit restants, deux seulement présentent des sols peu ou non carencés en Ntot, Pdispo et en Kéch sur 0-10 cm. Cependant, ils sont tous les deux déficients en Pdispo. Conclusions. Cette étude a permis de mettre en évidence l'importance d'une caractérisation préalable des sols, du choix de la position topographique et recommande l'application d'une fertilisation starter pour la réussite des reboisements. Les résultats de cette étude constituent une contribution au choix des sites les plus appropriés pour le reboisement à Madagascar
Apple DELLA Is Degraded Under Warm Temperature Conditions in <i>Nicotiana benthamiana</i> Leaves Through a COP1‐Dependent Mechanism
No full textInternational audienceIn apple (Malus domestica), flowering is repressed by the phytohormone gibberellin (GA) and high temperatures (> 27°C), but the molecular mechanisms underlying this repression remain unknown. In Arabidopsis thaliana (Arabidopsis), GA and temperature signaling converge on DELLA protein regulation, with both factors promoting DELLA degradation through independent 26S proteasome-mediated pathways. Here, we tested whether high-temperature-induced DELLA degradation is conserved in apple. Using the heterologous systems Arabidopsis and Nicotiana benthamiana, we characterized the function of the apple DELLA protein DELLA REPRESSOR OF ga1-3 (MdRGL1a) and found that high temperatures promote its degradation via a 26S proteasome-dependent mechanism. Additionally, MdRGL1a interacts with apple orthologs of Arabidopsis CONSTITUTIVELY PHOTOMORPHOGENIC1 (COP1) and SUPPRESSOR OF phyA-105 2 (SPA2), components of an E3 ubiquitin ligase complex that mediates protein ubiquitination and degradation. These findings suggest a conserved mechanism of temperature-induced DELLA degradation between apple and Arabidopsis. The degradation of MdRGL1a may underlie flowering suppression in apple under high temperatures, providing molecular insights that could aid in developing strategies to stabilize apple and other crop production in the face of climate change.</div
Grafting coffee for sustainability: Improving productivity, plant vigour and soil microbiome
No full textSource Agritrop Cirad (https://agritrop.cirad.fr/609708/) * Autres projets (id;sigle;titre): 101060393;BOLERO;(EU) Breeding for coffee and cocoa root resilience in low input farming systems based on improved rootstocks//International audienceCoffee is one of the most important traded tropical commodities globally, contributing significantly to the livelihood of millions of smallholder farmers worldwide. The coffee plant is frequently susceptible to biotic and abiotic stressors, including the cumulative pressure of climate change, affecting both bean yields and quality. Increasing pest and disease pressure and changing weather patterns, including extreme temperatures, abnormal precipitation (drought, flooding), and water scarcity, are putting the future of the coffee sector at risk, especially as most smallholder farmers depend on rain-fed agriculture. As part of developing adaptation strategies for farmers and building coffee farming systems that are resilient to climate change, as well as economically and environmentally sound, there is a need to develop plant material that is more resistant to biotic/abiotic stresses. The use of grafted plants on stress-tolerant rootstocks has been recommended as an effective and sustainable strategy for coffee crops to cope with climate change. This chapter provides an overview of grafting in coffee and its importance for productivity and health under environmental stresses, and connects grafting with recent advances in soil microbiome interactions. This chapter emphasises the important role of grafting in the development of new adaptive strategies to enhance resilience and mitigate climate change effects on coffee
Reproductive success of dispersers depends on the population of origin in Atlantic salmon
No full textInternational audienceAtlantic salmon (Salmo salar) is an iconic species of great socio-economic value, which is also known for its philopatric behaviour called ‘homing’. After spending one to several years in freshwater, juvenilesmigrate to marine areas for growth, remaining there for one to several years before returning as adults to their natal river to reproduce. However, some individuals can disperse to nearby or more distant rivers, leading to a metapopulation functioning. Theory predicts that dispersing individuals may have a lower fitness than local individuals, but this prediction has been rarely investigated in Atlantic salmon. The objectives of this study were to: i) identify the dispersers in a focal population (Nivelle River, France), and ii) compare their reproductive success with local individuals. We combined pedigree and populationgenetic approaches using 4331 individuals genotyped with 14 microsatellites and/or 164 SNPs over a sixteen years period. Population genetic assignment tests coupled with pedigree reconstruction revealed a high dispersal rate of 19.5% into the Nivelle population. Dispersal was male-biased and higher in single-sea-winter salmon than multi-sea-winter fish. On average, reproductive success was 15% lower for dispersing individuals than local ones. However, after accounting for sex and sea age, dispersers from some populations had a higher reproductive success than local individuals. Overall, we show an origin-dependent reproductive success of dispersing individuals, which illustrates the trade-off between gene flow and local adaptation
A genomic perspective on population structure and adaptation to aridity in the four-striped mouse Rhabdomys bechuanae in Southern Africa
No full textInternational audienceAs climate change drives rapid environmental shifts, crops face significant challenges due to their limited genetic diversity, which constrains their adaptive potential. Crop wild relatives —and potentially feral populations, which are wild populations derived from domesticated ones—are likely to be locally adapted to diverse environments and could serve as valuable reservoirs of genetic diversity for breeding and crop improvement. Exploring and conserving this genetic diversity is essential, as it preserves a broad spectrum of adaptations to varied environmental conditions. In this study, we investigate the genetic basis of local adaptation to climate and potential mismatches under future conditions in Brassica rapa (field mustard), a wild relative of turnip, Chinese cabbage, and pak choi, and a genome donor for Brassica napus (rapeseed). Seeds were collected through the BrasExplor project—a consortium coordinated by IGEPP (INRAE) with 11 partners from seven countries. A total of 62 spontaneous populations were sampled in Algeria, France, Italy, and Slovenia, revealing strong genetic structure between feral populations (from continental Europe) and wild populations (from Algeria and Sicily). We conducted genome–environment association analyses and applied the local score approach to identify highly significant genomic regions associated with climatic variables, including promising variants and candidate genes. However, broader genomic patterns suggest that adaptation to climate is not limited to a few loci but likely reflects a polygenic architecture involving multiple regions across the genome. While the inclusion of feral populations allows exploration of a broader climatic envelope and identifies variants potentially easier to introgress into crops, their reduced genetic diversity—likely due to domestication and rewilding bottlenecks—may limit our ability to capture the full spectrum of adaptive variation present in truly wild populations. This hypothesis was confirmed by repeating the analysis on a subset of wild populations, revealing a large number of additional candidate regions. We also conducted genomic offset (GO) analyses to estimate the potential mismatch between current allele frequencies and those expected under future climates. Several populations showed high GO values, suggesting nonoptimal allele frequencies in their future climate. Phenotypic data obtained in a common garden experiment indicated that GO may partially predict variation in fitness, but this relationship should be interpreted with caution. More specifically, fitness proxies (seed number and weight) may be biased in feral populations, and much of the adaptive signal specific to wild populations is not captured, limiting predictive power for those populations. These findings highlight the complex genetic architecture of climate adaptation in B. rapa and underscore both the potential and the limitations of genomic tools for guiding conservation and crop improvement strategies in a changing climate
Impacts of cattle farming practices and associated livestock systems on energy balances and greenhouse gas emissions in the municipality of Paragominas - State of Pará - Amazonia
No full textInternational audienceGreenhouse gas (GHG) emissions and energy use are important parameters in the development of sustainable livestock systems. On-farm management practices can maximise energy efficiency and reduce gas emissions, however, these practices have yet to be identified and characterized. This study evaluated the eco-efficiency of cattle farming, considering a combination of the energy balance and GHG emissions from 33 farms in the Brazilian Amazon (Paragominas - Pará), using a diagnostic tool adapted to the region. The farms represented the diverse production systems operating in the area, distinguished by their activity (dairy, breeder, breeder-fattener and fattener), degree of intensification, and agrarian situation (corresponding to the farm’s geographical location and social and economic inclusion in the municipality). Energy efficiency on beef cattle farms is on average 16.29 GJ/t live weight (min = 1.74 GJ/t, max = 43.01 GJ/t), and on dairy farms 2.74 GJ/1000 L (min = 0.17, max = 6.48), i.e., respectively 46% and 40% lower than the figures reported by studies conducted in metropolitan France. Improved grazing enhances natural resources by optimising the use of forage biomass, which has a positive impact on energy efficiencies. The purchase of young animals and fertilisation account for a high percentage of energy consumption, with fuel constituting the major part of the direct energy consumed. GHG emissions are on average 17.40 teqCO 2 /t live weight (min = 6.13, max = 40.85), similar to those of metropolitan France (14 teqCO 2 /t). When emissions from livestock and storage by forests and pastures over 20 years of age are taken into account, farms have a positive carbon balance. The deforestation levels of each farm over the past 20 years have a strong impact on this balance sheet, which can make it negative. This study highlights the effectiveness of the method in identifying systems and practices that could help farms achieve greater sustainability in terms of energy use and GHG emissions
Offspring number, size, and survival: State‐dependent optimization of litter size in a long‐lived capital breeder
No full textInternational audienceSeventy-five years ago, Lack proposed that there should be an optimal clutch size shared by all individuals in a population and favored by natural selection, which maximizes the number of recruited offspring. While some studies support this “common optimum” hypothesis, others have shown that the optimal clutch size depends on maternal state (e.g., age and body condition, “state-dependent optimization”). These contrasting results suggest that the degree of state dependency might itself depend on the ecological context (e.g., capital vs. income breeding). Furthermore, almost all these studies were conducted on fast-living species and have ignored interdependencies among variables such as maternal age and condition. Here, we test whether females share a common optimal litter size or have a state-dependent optimal litter size in a slow-paced capital breeder, the polar bear (Ursus maritimus). To do so, we assess the influences of (1) maternal state on litter size, (2) maternal state and litter size on cub mass, and (3) maternal state, litter size, and cub mass on cub survival, using path analysis to account for interdependencies among variables and capture–recapture modeling to estimate cub survival. We use 34 years (1992–2025) of individual-based data from a polar bear subpopulation in the Svalbard region of Norway. In accordance with the state-dependent optimization hypothesis, litter size varied with maternal age and size. Middle-aged and sized females had the highest probability of having twins. Old and large females more often had triplet litters. Cub mass decreased with increasing litter size, whereas litter mass increased, meaning females with a large litter allocated more resources to reproduction. Cub mass in turn strongly predicted cub survival, indicating that offspring survival was traded against offspring number. In middle-aged and old females, productivity—the number of cubs surviving their first year—increased with litter size, in accordance with the state-dependent optimization hypothesis. Overall, our results are consistent with a state-dependent optimization of litter size in this large, slow-paced mammal producing small litters. State dependence of litter size may be more likely in capital breeders as the amount of energy available for reproduction is known in advance
Exploring the impact of yeast derivatives on aromatic and sensory profiles of white and red wines: a multifactorial study
No full textInternational audienceSpecific inactivated Yeast Derivatives (SYDs) are obtained from S. cerevisiae yeasts by various processes (thermal, mechanical, and enzymatic) and have diverse oenological applications to improve wine quality. However, different impacts on wine sensory characteristics and aromas were reported depending on SYD types and fractions, wine matrices, and experimental settings. Few works have examined the impact of SYDs on aromas while also considering their effects on wine macromolecules influencing organoleptic properties. This work aimed to implement a multifactorial approach to study the impact of different SYDs on the aromatic composition and the sensory profile of one white and one red wine at a pilot scale. Concomitant analyses of wine characteristics, including oenological properties, polyphenolic and polysaccharidic compositions, were performed. Wines were treated with various S. cerevisiae SYDs provided by Lallemand at oenological dosages. The impacts on olfactory and gustatory properties were studied with a sensory panel of trained judges using monadic profiling. The volatile profile of wines was determined by HS-SPME-GC-MS, polysaccharide content by GC-MS following hydrolysis and derivatisation, and polyphenol content and profiles by UV-visible spectrophotometry and size-exclusion chromatography. Yeast derivative and wine matrix effects were observed in the variation of volatile compounds in treated wines compared to the control wine for all chemical classes. Results from the chemical analysis showed that the release of aroma compounds in the headspace varied according to the SYDs used. This effect was accentuated in the white wine, thus highlighting the matrix effect. Correlations between significant aroma variations in the headspace and their hydrophobicity were found. The wines resulting from the different treatments could be separated by sensory and principal component analysis (PCA), and according to the modulated sensory attributes, such as red and black fruit, citrus. In addition to improving the understanding of the interaction phenomena between SYDs and aroma compounds in wine, these results may also help anticipate the sensory and aromatic impacts of their use in oenological applications