128 research outputs found
Recherche de déterminants génétiques et moléculaires impliqués dans l'architecture racinaire et nodulaire des légumineuses et contribuant à une amélioration de la nutrition azotée
Grain legume pulse crops are of great interest to allow a production of seeds high nutritional value without any contribution of nitrate fertilizer. The nitrogen nutrition of legumes depends indeed mainly on the fixation in nodules of atmospheric dinitrogen through the plant-rhizobium symbiosis, and to a lesser extent, absorption by roots of soil mineral nitrogen.A better understanding has been obtained on the genetic control of the development of roots and nodules and on their impact on nitrogen nutrition. High genetic variability of these characters has been detected, and the existence of genetic correlations between them demonstrated. A quantitative genetic approach has identified several genomic regions that may be involved in their variations. The two different ways to improve nitrogen nutrition were also studied: the improvement of nitrogen acquisition by roots through a detailed study of a root architecture mutant, and the improvement of symbiosis via the study of the ability of peas to promote symbiotic associations with the most effective rhizobia.The results provide interesting bases for the design of a pea nitrogen-nutrition âideotypeâ. Beyond the essential complementarity between the two pathways of nitrogen acquisition, it is necessary to optimize the interaction between the two symbiotic partners, which is a complex mechanism involving nodules formation and functioning in connection with complex signaling and trophic interactions between the partners and intra-plant.La culture de LĂ©gumineuses prĂ©sente le double intĂ©rĂȘt de permettre une production de graines Ă haute valeur nutritionnelle sans nĂ©cessitĂ© dâun apport dâengrais azotĂ©. La nutrition azotĂ©e des lĂ©gumineuses dĂ©pend en effet majoritairement de la fixation symbiotique de lâazote atmosphĂ©rique rĂ©alisĂ©e par des bactĂ©ries du sol, les rhizobia, au sein des nodositĂ©s, et dans une moindre mesure, de lâassimilation de lâazote minĂ©ral du sol par les racines.Une meilleure comprĂ©hension a Ă©tĂ© acquise sur le contrĂŽle gĂ©nĂ©tique de la mise en place des racines et des nodositĂ©s et sur leur impact sur la nutrition azotĂ©e. Une grande variabilitĂ© gĂ©nĂ©tique pour ces caractĂšres a Ă©tĂ© mise en Ă©vidence, ainsi que lâexistence de corrĂ©lations gĂ©nĂ©tiques entre eux. Une approche de gĂ©nĂ©tique quantitative a permis dâidentifier des rĂ©gions gĂ©nomiques pouvant ĂȘtre impliquĂ©es dans leurs variations. Deux pistes dâamĂ©lioration de la nutrition azotĂ©e ont aussi Ă©tĂ© Ă©tudiĂ©es : lâamĂ©lioration de lâacquisition dâazote par les racines Ă partir dâune Ă©tude dĂ©taillĂ©e dâun mutant de dĂ©veloppement racinaire, et lâamĂ©lioration de la symbiose via lâĂ©tude de la capacitĂ© des pois Ă favoriser les associations symbiotiques avec les rhizobia les plus performants.Les rĂ©sultats obtenus apportent des bases de rĂ©flexion concernant la conception dâun idĂ©otype de nutrition azotĂ©e. Au-delĂ de la complĂ©mentaritĂ© indispensable entre les deux voies dâacquisition dâazote, il convient dâoptimiser lâinteraction entre les deux partenaires symbiotiques, mĂ©canisme complexe mettant en jeu la formation et le fonctionnement des nodositĂ©s, en lien avec une signalĂ©tique et des interactions trophiques entre partenaires et intra-plante
: Cognitive and behavioural coaching of managers & leaders in public research. Study of the coaching of a research director at INRAE
Ăcole thĂ©matiqueThe world of public research seems at first sight to be very little concerned by themanagement issues of the business world in which the right decisions must be taken and forwhich there is an obligation to perform. The very idea of coaching researchers seemsincongruous. The purpose of this study is to challenge this idea, by describing precisely whatthe profession of researcher is in the world of public research - their belonging to very complexstructures and the demanding challenges they have to face - then by studying thecontributions of cognitive-behavioural coaching methodologies. The analysis of the practiceshows that coaching based on constructivist psychology can lead to a better practice of theprofession of a researcher with managerial responsibilities.Le monde de la recherche publique semble a priori trĂšs peu concernĂ© par des problĂ©matiquesde management du monde de lâentreprise dans lequel les bonnes dĂ©cisions doivent ĂȘtre priseset pour lequel il existe une obligation de performance. LâidĂ©e mĂȘme de coaching dechercheurs paraĂźt incongrue. Le propos de ce mĂ©moire est de questionner cette idĂ©e, endĂ©crivant prĂ©cisĂ©ment ce quâest le mĂ©tier de chercheur dans le monde de la recherchepublique - leur appartenance Ă des structures trĂšs complexes et lâexigence des enjeuxauxquels ils doivent rĂ©pondre - puis en Ă©tudiant les apports de mĂ©thodologies de coachingcognitivo-comportemental. Lâanalyse de la pratique montre quâun accompagnement basĂ© surde la psychologie constructiviste peut conduire Ă une meilleure pratique du mĂ©tier dâunchercheur ayant des responsabilitĂ©s de manage
Research of genetic and molecular determinants involved in the nodulated root system architecture of legumes and contributing to improved nitrogen nutrition
La culture de LĂ©gumineuses prĂ©sente le double intĂ©rĂȘt de permettre une production de graines Ă haute valeur nutritionnelle sans nĂ©cessitĂ© dâun apport dâengrais azotĂ©. La nutrition azotĂ©e des lĂ©gumineuses dĂ©pend en effet majoritairement de la fixation symbiotique de lâazote atmosphĂ©rique rĂ©alisĂ©e par des bactĂ©ries du sol, les rhizobia, au sein des nodositĂ©s, et dans une moindre mesure, de lâassimilation de lâazote minĂ©ral du sol par les racines.Une meilleure comprĂ©hension a Ă©tĂ© acquise sur le contrĂŽle gĂ©nĂ©tique de la mise en place des racines et des nodositĂ©s et sur leur impact sur la nutrition azotĂ©e. Une grande variabilitĂ© gĂ©nĂ©tique pour ces caractĂšres a Ă©tĂ© mise en Ă©vidence, ainsi que lâexistence de corrĂ©lations gĂ©nĂ©tiques entre eux. Une approche de gĂ©nĂ©tique quantitative a permis dâidentifier des rĂ©gions gĂ©nomiques pouvant ĂȘtre impliquĂ©es dans leurs variations. Deux pistes dâamĂ©lioration de la nutrition azotĂ©e ont aussi Ă©tĂ© Ă©tudiĂ©es : lâamĂ©lioration de lâacquisition dâazote par les racines Ă partir dâune Ă©tude dĂ©taillĂ©e dâun mutant de dĂ©veloppement racinaire, et lâamĂ©lioration de la symbiose via lâĂ©tude de la capacitĂ© des pois Ă favoriser les associations symbiotiques avec les rhizobia les plus performants.Les rĂ©sultats obtenus apportent des bases de rĂ©flexion concernant la conception dâun idĂ©otype de nutrition azotĂ©e. Au-delĂ de la complĂ©mentaritĂ© indispensable entre les deux voies dâacquisition dâazote, il convient dâoptimiser lâinteraction entre les deux partenaires symbiotiques, mĂ©canisme complexe mettant en jeu la formation et le fonctionnement des nodositĂ©s, en lien avec une signalĂ©tique et des interactions trophiques entre partenaires et intra-plante.Grain legume pulse crops are of great interest to allow a production of seeds high nutritional value without any contribution of nitrate fertilizer. The nitrogen nutrition of legumes depends indeed mainly on the fixation in nodules of atmospheric dinitrogen through the plant-rhizobium symbiosis, and to a lesser extent, absorption by roots of soil mineral nitrogen.A better understanding has been obtained on the genetic control of the development of roots and nodules and on their impact on nitrogen nutrition. High genetic variability of these characters has been detected, and the existence of genetic correlations between them demonstrated. A quantitative genetic approach has identified several genomic regions that may be involved in their variations. The two different ways to improve nitrogen nutrition were also studied: the improvement of nitrogen acquisition by roots through a detailed study of a root architecture mutant, and the improvement of symbiosis via the study of the ability of peas to promote symbiotic associations with the most effective rhizobia.The results provide interesting bases for the design of a pea nitrogen-nutrition âideotypeâ. Beyond the essential complementarity between the two pathways of nitrogen acquisition, it is necessary to optimize the interaction between the two symbiotic partners, which is a complex mechanism involving nodules formation and functioning in connection with complex signaling and trophic interactions between the partners and intra-plant
- âŠ