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Cocoyam (Xanthosoma sagittifolium (L.) Schott) genetic resources and breeding: a review of 50 years of research efforts
No full textInternational audienceCocoyam (Xanthosoma sagittifolium (L.) Schott) cultivated throughout the wet tropics is consumed by hundreds of millions. This underexploited species plays a major role for food security but is not under the mandate of the international research system. Development activities are left to national institutions in developing countries, the conservation and characterization of its genetic resources are uncoordinated. Breeding activities are rare and isolated. Despite these major constraints, significant research efforts have been made over the last fifty years and are being discussed in the present review. The taxonomic position of many Xanthosoma spp. is suspicious and cultivated forms of unknown species are often called X. sagittifolium. In most countries, germplasm collections are small with accessions number ranging from a few to 80. They are often grouped based on different pigmentations on their vegetative parts and side-cormels flesh colors. Limited variation in quantitative traits is observed. Isozymes, random amplified polymorphic DNA (RAPD), amplified fragment length polymorphism (AFLP), inter-retrotransposon amplified polymorphism (IRAP) and simple sequence repeat (SSR) markers have been used and reveal limited allelic diversity. Significant investments have been made in the development of various tissue culture protocols to ease preservation and sanitation. Despite controversial reports regarding sterility or incompatibility, the efforts made to induce flowering, to cross-pollination and to raising hybrids were successful. It appears that there are no major technical and biological constraint to conventional cocoyam breeding. Unfortunately, most programs are based on narrow genetic bases and if cocoyam breeding is to have any future, there is an urgent need to encourage the international exchange of selected germplasm
Signal partitioning between native and introduced forest birds of Hawai‘i Island
No full textInternational audienceBirds use sound for conspecific communication. According to the acoustic niche hypothesis, they avoid signal competition with other species by partitioning sound in frequency and time. Others have observed introduced species changing the vocal behavior of native species; however, community-level effects of multiple introduced species remain unknown. Hawai‘i, with its legacy of bird extinctions followed by a surge of human introductions, offers a unique opportunity to study acoustic signal partitioning between native and introduced species. We predicted that communities with higher percentages of introduced birds would exhibit more acoustic overlap between members of different species due to shorter time frames to evolve signal partitioning. Using autonomous recording units, we recorded forest bird communities during the summer in montane primary and secondary forests as well as a low-elevation agricultural site. Random samples of recordings from each site were visualized as spectrograms, and all bird vocalizations ≥5 decibels above background noise were identified and labeled by species. Frequency range and the proportion of overlap with other species were compared between native and introduced species. We also used a null model which randomized the start time of each bird vocalization within a location over 500 iterations, then compared the amount of heterospecific signal overlap in the randomizations to that observed in the recordings. While native and introduced species generally used similar frequency ranges, native-native heterospecific species vocalization pairs had a significantly higher proportion of overlap than introduced-native and native-native pairs. Additionally, the incidence of signal overlap in the original recordings tended to be lower than in the null model randomizations, but this difference was not significant, and was not influenced by the percentage of introduced species vocalizations at the site. The lack of significant difference between observed and null model signal overlap occurrence suggests that native and introduced forest birds were not partitioning acoustic space either spectrally or temporally, and that introduced birds are not strongly influencing signal partitioning in forest bird communities of Hawai‘i. However, this may have been a consequence of recording during the non-breeding season, and future work should compare vocal activity in native and introduced birds throughout the year
Decrease in radiocesium adsorption of illite induced by soil organic matter: Quantity or quality?
No full textInternational audienceOrganic matter blocks highly selective frayed edge sites on clay minerals and reduces radiocaesium adsorption. The effects of different soil organic matter on Cs adsorption on illite have been investigated. The quantity and quality of soil organic matter was varied by extracting from three contrasting soils and varying extraction conditions. Extracted organic matter was quantified, and analysed using UV and fluorescent spectroscopy. Cs adsorption was markedly lower in soil aqueous extracts, than in simple electrolyte solution at the same ionic strength (IS). Part of the decrease was attributed to soluble soil potassium. After correction for ionic strength and potassium, the relative distribution coefficient of Cs, KdIS,K, decreased with increasing dissolved organic carbon (DOC) concentration. The correlation between KdIS,K and DOC was largely unchanged by taking into account any of the measured spectral parameters. We find no evidence that molecular size and composition of organic coatings determine their effect on the Cs adsorption properties of illite
History of breeding programmes for fungus resistant grape varieties in Europe, France and the Occitanie region
No full textA table in French about this literature review is available upon request to the corresponding author.International audienceFungus tolerant grape varieties (RVs) are emerging as a promising solution in a viticultural context characterised by growing societal, environmental, and regulatory tensions. Since the 1930s, several countries have launched research programmes that aim at developing disease-resistant hybrids. Today, 66 resistant grape varieties are registered in at least one of the European catalogues. The historical overview and dynamic integration of RV have not been the subject of a large number of scientific articles. This makes it necessary to explore grey literature such as Vitisphère (www.vitisphere.com), a French daily online magazine created in 2000 specialised in wine industry. Through a press review, this article provides historical background to European breeding programmes and an overview of their perception in France and Occitanie, gathering over 543 articles on the topic of RVs published between 2009 and end June 2024
An integrative study of new environmental and cultural data from the Hoabinhian of Laang Spean Cave (Cambodia) including modern human remains
No full textInternational audienceAlthough the Hoabinhian culture is renowned for its unifacial pebble tools and its discovery dates back more than a century, only a handful of sites provide complete information on this period. The site of Laang Spean, in Cambodia, has recently been described as a burial cave for the Neolithic period, but it was previously known as an emblematic Hoabinhian site for Cambodia. More comprehensive studies indicate that it offers a wide window onto the settlement of the Hoabinhian between 12900 and 5000 cal BP. The archaeological layer of the Hoabinhian culture at Laang Spean include faunal, human and lithic remains that enrich our understanding of the environment and way of life of this ancient culture. The faunal assemblage, dominated by bovines, tortoises, molluscs, and cervids, reflects a diverse ecosystem and the adaptability of the Hoabinhian people. The presence of both humid and dry forest indicators, alongside significant wetland areas, suggests their ability to exploit a variety of habitats. The lithic assemblage, characterized by a lower representation of unifaces and greater use of split cobbles, reflects a continuity in basic lithic reduction strategies with minor diachronic changes in raw material selection and tool production, possibly reflecting technological adaptations and increased intensity of occupation. The discovery of human remains, though challenging to contextualize precisely, contributes to understanding settlement patterns and cultural links in prehistoric Southeast Asia. The new data allow for a deeper interpretation of the environmental adaptations and hunting strategies of the Hoabinhian people, including their responses to climatic changes, such as the end of the Younger Dryas. This enhanced knowledge significantly contributes to our comprehension of the environmental dynamics and subsistence practices in prehistoric Southeast Asia and underscores the necessity of reassessing key Hoabinhian sites with modern excavation and dating techniques
Modifications du protéome d'un champignon ectomycorhizien par la présence de sa plante-hôte : importance pour les échanges nutritionnels champignon-plante
No full textNational audienceLes associations mycorhiziennes entre les racines des plantes et les champignons du sol sont caractérisées par des échanges de nutriments entre les deux partenaires. Ces échanges s’effectuent au niveau de l’interface cellules fongiques/cellules racinaires où il n’y a pas de communication directe entre les deux types de cellules. Dans les ectomycorhizes, cette interface d’échange est localisée dans le cortex racinaire et est appelée « réseau de Hartig ». Nous avons émis l’hypothèse que dans le réseau de Hartig, certaines protéines fongiques, en particulier les transporteurs d’éléments minéraux comme le potassium (K), le phosphate (Pi) ou l’azote (N), pourraient être modifiées quantitativement ou qualitativement via des modifications post-traductionnelles. Pour aborder cette question nous avons utilisé l’association entre le pin maritime (Pinus pinaster) et le basidiomycète ectomycorhizien Hebeloma cylindrosporum. Nous avons étudié le protéome du champignon, dont le génome est séquencé, en fonction de la présence/absence de la plante-hôte et du statut P du champignon (plus/moins P). Pour cela, les thalles ont d’abord été cultivés en conditions plus ou moins P puis ont été incubés dans un milieu très simplifié, en présence ou en absence du pin maritime. Ce système d’incubation in vitro permet de mimer l’espace apoplasmique du réseau de Hartig des ectomycorhizes, zone très difficile à étudier autrement. Après 48 h d’incubation, les thalles ont été collectés et les protéines totales extraites. Le protéome a été analysé pour les différentes conditions, ainsi que son degré de phosphorylation. Les résultats obtenus montrent que la présence du pin maritime modifie la quantité de protéines et/ou leur degré de phosphorylation. L’ampleur des modifications dépend du statut P du champignon, avec beaucoup plus de modifications lorsqu’il est préalablement carencé en Pi. Par exemple, l’abondance de 52 accessions est modifiée en -P contre 18 en +P. De même, la présence des racines de pin pendant ces 48 h induit la phosphorylation de nombreux transporteurs, dont deux transporteurs de Pi et de peptides, suggérant que la plante-hôte pourrait effectivement modifier les propriétés des transporteurs fongiques pour moduler les flux de nutriments dans le réseau de Hartig
Recommandations pour l'usage des IA génératives comme assistant personnel au sein d'INRAE
No full textRecommandations INRAE sous forme de fiche. Collection "Bonnes pratiques autour du numérique pour la science"Depuis plus de 10 ans déjà, les systèmes d’intelligence artificielle (IA) nous assistent dans des tâches quotidiennes sans nécessairement que nous en ayons pris conscience (correction orthographique, dictées de messages, traduction de textes, traitement des photos de nos smartphones...). D’ici la fin de la décennie, il est vraisemblable que les systèmes d’intelligence artificielle nous accompagneront en continu et dans beaucoup d’autres tâches du quotidien. Cela pourrait prendre la forme de nombreux assistants personnels, qui accompliraient des tâches répétitives, appuieraient la réflexion et la prise de décision, et accéléreraient le travail de groupe. Les IA évoluent très rapidement et il parait aujourd’hui nécessaire d’accompagner ce changement dans le cadre du travail à INRAE. Cette note de recommandations présente les premières lignes directrices. Un plan d’action suivra dans un second temps
Institutional Pluralism and Interactions Between Normative Systems: A Theoretical Overview
No full textInternational audienceThis theoretical chapter explores the polymorphic, dynamic and contextual aspects of institutions. It proposes first a short literature review that addresses institutional pluralism. Three main approaches are distinguished: one that focuses on the social and institutional regulation of the economy, one that examines the existence of non-state legal norms and one that addresses the diversity of norms in their empirical expression. The main contributions of each approach are identified as are some of their limitations. This is followed by a review of the works that specifically deal with the ways in which different normative regimes interact. We argue that researchers rarely theorise these interrelations as such. Pointing to the necessity of constructing typologies of modes of interaction between normative systems, the chapter concludes by calling for empirical research to document the multiplicity of institutional forms made up of a large repertoire of norms that are constantly interacting and evolving
Metabolite Variations during the First Weeks of Growth of Immature Citrus sinensis and Citrus reticulata by Untargeted Liquid Chromatography–Mass Spectrometry/Mass Spectrometry Metabolomics
No full textInternational audienceImmature citruses are an important resource for the pharmaceutical industry due to their high levels of metabolites with health benefits. In this study, we used untargeted liquid chromatography-mass spectrometry (LC-MS) metabolomics to investigate the changes associated with fruit size in immature citrus fruits in the first weeks of growth. Three orange cultivars (Citrus sinensis 'Navel', Citrus sinensis 'Valencia', and Citrus sinensis 'Valencia Late') and a mandarin (Citrus reticulata Blanco 'Fremont') were separated into eight fruit sizes, extracted, and analyzed. Statistical analyses revealed a distinct separation between the mandarin and the oranges based on 56 metabolites, with an additional separation between the 'Navel' orange and the 'Valencia' and 'Valencia Late' oranges based on 21 metabolites. Then, metabolites that evolved significantly with fruit size growth were identified, including 40 up-regulated and 31 down-regulated metabolites. This study provides new insights into the metabolite modifications of immature Citrus sinensis and Citrus reticulata in the first weeks of growth and emphasizes the significance of including early sampled fruits in citrus maturation studies
Unravelling the diversity of technical operations in diversified perennial-based cropping systems: the case of smallholder immature rubber intercropped with pineapple in Rayong, Thailand
No full textInternational audienceIntroductionDiversification practices in perennial-based cropping systems (e.g. agroforestry, intercropping, etc.) are promoted for their global positive effects on the agroecosystems’ performances at the plot scale (Beillouin et al., 2019). In Thailand, intercropping with various crops is often adopted in smallholder rubber plantations during the first four years, to cope with the challenges of the immature period. In the literature, these cropping systems are usually characterized by describing the crop choice in the inter-rows only, without considering the associated technical operations (Simon et al., 2024). This study aims at (1) characterizing thoroughly the diversity of technical operations applied to intercrops and rubber trees and; (2) understanding the relationships between the managements of intercrops and rubber trees.Materials and methodsWe conducted interviews in Rayong province, Thailand, with 24 farmers that had at least one rubber plantation between 1- and 4 years old, intercropped with pineapple. All the technical operations applied on pineapple and rubber trees respectively were recorded on a timeline. The "Typ-iti” method (Renaud-Gentié et al., 2014), combining multivariate analysis, clustering and association rules, was used to explore the diversity of technical management routes (TMRs) adopted on pineapple. The technical operations applied to rubber trees were compared with pineapple management clusters through mixed linear models to analyze possible relationships between managements in the inter-rows and rubber rows.ResultsRegarding pineapple management, three initial clusters were observed based on TMR from the soil preparation to the first harvest. Clusters 1 and 2 were constituted of 11 and 8 TMRs respectively, implemented by farmers producing pineapple for industries. They were both characterized by the use of fruit crowns as planting material and an intensive flower induction, but differing in terms of chemical fertilization and weeding. Cluster 3 was constituted of six TMRs, implemented by farmers producing pineapple for local markets, and was characterized by the use of plant suckers as planting material only, with less chemical products used compared to Clusters 1 and 2. A last cluster, named Cluster 4, consisted of TMRs implemented by all farmers, spanning from the first harvest to the second, and was distinguished by a decrease in chemical inputs. A diversity of technical operations was also observed on rubber trees, particularly in the frequency of chemical fertilizer applications, the frequency of weeding operations and the weeding methods used. However, the differences in technical operations applied to rubber trees were not linked to the pineapple management.DiscussionThis study highlights the large diversity of technical operations in rubber + pineapple immature plantations. Contrary to expectations and in contrast to what was observed in other perennial cropping systems (Koussihouèdé et al., 2020), pineapple and rubber trees are managed independently. More globally, our results underline the need to not only consider the crop choice but also the possible diversity of technical operations and the plot level strategies of farmers to better understand the variability of performances in a multicriteria assessment (Perrin et al., 2023).ReferencesBeillouin, D., Ben Ari, T., Makowski, D., 2019. Evidence map of crop diversification strategies at the global scale. Environmental Research Letters 14, 123001. https://doi.org/10.1088/1748-9326/ab4449Côte, F.X., Rapidel, B., Sourisseau, J.M., Affholder, F., Andrieu, N., Bessou, C., Caron, P., Deguine, J.-P., Faure, G., Hainzelin, E., Malezieux, E., Poirier-Magona, E., Roudier, P., Scopel, E., Tixier, P., Toillier, A., Perret, S., 2022. Levers for the agroecological transition of tropical agriculture. Agron. Sustain. Dev. 42, 67. https://doi.org/10.1007/s13593-022-00799-zKoussihouèdé, H., Clermont-Dauphin, C., Aholoukpè, H., Barthès, B., Chapuis-Lardy, L., Jassogne, L., Amadji, G., 2020. Diversity and socio-economic aspects of oil palm agroforestry systems on the Allada plateau, southern Benin. Agroforest Syst 94, 41–56. https://doi.org/10.1007/s10457-019-00360-0Perrin, A., Yannou-Le Bris, G., Angevin, F., Pénicaud, C., 2023. Sustainability assessment in innovation design processes: place, role, and conditions of use in agrifood systems. A review. Agron. Sustain. Dev. 43, 10. https://doi.org/10.1007/s13593-022-00860-xRenaud-Gentié, C., Burgos, S., Benoît, M., 2014. Choosing the most representative technical management routes within diverse management practices: Application to vineyards in the Loire Valley for environmental and quality assessment. European Journal of Agronomy 56, 19–36. https://doi.org/10.1016/j.eja.2014.03.002Simon, C., Thoumazeau, A., Chambon, B., Sajjaphan, K., Metay, A., 2024. Diversity, adoption and performances of inter-row management practices in immature rubber plantations. A review. Agron. Sustain. Dev. 44, 12. https://doi.org/10.1007/s13593-024-00944-