309 research outputs found

    Participatory Plant Breeding Methods for Organic Cereals

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    Formal breeding methods were not always suitable to address the very large diversity of both environmental conditions and end-user needs. Both were frequently encountered either in marginal areas of developing countries or in organic farms of EEC. Participatory plant breeding (PPB) methods represent alternatives aimed to improve local adaptation breeding, to promote genetic diversity, to empower farmers and rural communities. The term PPB refers to a set of breeding methods usually distinguished by the objectives (functional or process approach), institutional context (farmer-led or formal-led), forms of interaction between farmers and breeders (consultative, collaborative or collegial), location of breeding (centralized or decentralized), stage of farmers participation in the breeding scheme (participatory varietal selection or participatory plant breeding)
 Among all these methods, the best strategies for organic breeding and their impacts on breeding techniques are discussed. A PPB program actually conducted at INRA – Montpellier (F), involves the whole organic durum wheat interprofessional organization, from farmers to consumers. It is used to assess the interest of a multidisciplinary approach and to discuss the role of each participant in such program. Must participation be seen as a means towards an end or an end in itself

    Innovation and research in organic farming: A multi‐level approach to facilitate cooperation among stakeholders

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    A wider range of stakeholders is expected to be involved in organic research. A decision‐support tool is needed to define priorities and to allocate tasks among institutions. Based on research and management experience in organic research, the authors have developed a framework for experimental and research projects. The framework is based on a multi‐level approach. Each level is defined according to the directness of the innovation impact on the organic systems. The projects carried out for each level were assessed over a ten-year period. Two applications are presented: analysis of crop protection strategies in horticulture and plant breeding programmes. When combined with four development models of organic farming, this multi‐level analysis appears to be promising for defining research agendas

    Cereal cultivars innovations adapted to organic production: A new challenge

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    To face and better manage the development of new varieties in a society calling for more and more transparency, the French National Research Institute (INRA) has get involved in an ambitious reflexive program about the question of "impacts, acceptability and management of varietal innovations" engaging all its thematic research departments. New collaboration between social and technical sciences are promoted to produce, from exemplary case studies, generic concepts and tools to assess the different types of impact of a new variety. Breeding and management of new genetic materials adapted to organic farming conditions constitute an appropriate theme to develop such an integrated process. A pluridisciplinary research team, associating plant breeders, soil scientists, ecologists, agronomists, economists, sociologists, in close collaboration with professionals , will try to assess both the agroenvironmental and socioeconomic impacts of changes, by studying current dynamics around original durum wheat and rice cultivars adapted to organic production in different territories

    Ability of new durum wheat pure lines to meet yield stability and quality requirements in low input and organic systems

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    Low-input production schemes adopted in organic or conventional farms require crop varieties that combine good product quality and high yield stability under non optimal environmental conditions (Gooding et al., 1999). These traits are not yet found among the durum wheat genotypes available in France. Consequently the cultivation of this crop is hardly successful in stockless organic farms in southern France, which are characterised by very low nitrogen resources. Some hopes emerged with the identification of new durum wheat pure lines with a high grain protein content in breeding experiments conducted near Montpellier in 2001 and 2002. The aim of the present work was to confirm and elucidate the origin of the enhanced protein performance of these new lines through a field experiment with nitrogen resources ranging from very low to sub-optimal levels

    An integrated study of the development of organic rice cultivation in the Camargue (France)-

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    In the Camargue, rice and durum wheat are associated in rotations that have an ambivalent ecological impact: on the one hand, these two crops contribute to the preservation of the surrounding ecosystem, while on the other hand, when cropped intensively, they can threaten the ecological equilibrium of this protected area. In this context, organic agriculture would seem to be an alternative adopted by a certain number of producers and processors. However, the pioneers of this practice encounter numerous problems, both agronomic and economic. The study presented here aims: to construct a pluridisciplinary approach to analyse the conditions of the development of organic cereal cultivation in the Camargue: to identify the principal factors that limit the development of this new practice: to produce knowledge useful in helping ricegrowers put into practice organic cropping systems

    Diversity of organic farming systems: Challenges for the construction of markets, varieties and plant breeding techniques

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    New societal values call for the diversification of agriculture to fit contrasted environments. This process can be depicted by four models defined by two axes, a socio-economic axis (individual logic vs. collective governance), and an agro-ecological axis (analytical vs. systemic approaches). These models differ in: (i) their objectives (from improvement in yield to the empowerment of farmers), (ii) their specific expectations with respect to genotypes (from inherited genetic resources to varieties that represent genetic, ethical and social progress), and (iii) their representations of the environment (from a simple interaction between the bio-physical environment and crop management, to a complex interaction including the skills of stakeholders, outlets, regulations and society). Taking this diversity into account changes the way plant improvement is envisioned. Depending on the model, the five classic stages of plant improvement (setting objectives, creating variability, selecting, evaluating and disseminating) may be called into question. Between the existing analytical model (model I) and a holistic model (model IV) that remains to be developed, lies the challenge of ensuring the sustainability, efficiency and acceptability of plant breeding and resulting innovations

    From Ideotype to Realtype concept: Dynamic management of plant breeding by a multidisciplinary and participatory way. Example of organic durum wheat

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    A travers l’exemple du blĂ© dur, les auteurs explorent l’évolution temporelle de la notion d’idĂ©otype mais aussi comment la diversification actuelle des environnements en AB influe sur la diversification des idĂ©otypes et rend nĂ©cessaire une dĂ©marche dynamique et participative d’amĂ©lioration des plantes. Cette façon renouvelĂ©e de concevoir et gĂ©rer la sĂ©lection amĂšne Ă  dĂ©passer la notion d’idĂ©otype, qui reste associĂ©e Ă  des critĂšres de sĂ©lection a priori, pour prĂ©fĂ©rer le terme de « realtype », qui traduirait la mise Ă  l’épreuve de l’idĂ©otype Ă  la rĂ©alitĂ© des terrains. Ce n’est donc pas la construction de l’idĂ©otype « par rapport Ă  » mais bien « dans » le contexte qui est recherchĂ© et permise par un dispositif collectif reprĂ©sentant la diversitĂ© des acteurs concernĂ©s et des compĂ©tences nĂ©cessaires

    Relativistic calculations of pionic and kaonic atoms hyperfine structure

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    We present the relativistic calculation of the hyperfine structure in pionic and kaonic atoms. A perturbation method has been applied to the Klein-Gordon equation to take into account the relativistic corrections. The perturbation operator has been obtained \textit{via} a multipole expansion of the nuclear electromagnetic potential. The hyperfine structure of pionic and kaonic atoms provide an additional term in the quantum electrodynamics calculation of the energy transition of these systems. Such a correction is required for a recent measurement of the pion mass

    La construction d’une dĂ©marche interdisciplinaire Ă  partir de l’émergence de la cĂ©rĂ©aliculture biologique en Camargue: le projet CEBIOCA

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    La céréaliculture biologique apparait comme une alternative aux modes de production conventionnels, pour un nombre croissant d'agriculteurs de Camargue. Le programme CEBIOCA cherche à appuyer le développement de ce prototype d'agriculture en favorisant l'élaboration de pratiques agricoles pertinentes, la production de matériel végétal adapté et la mesure des impacts de la conversion à l'AB. Un groupe de travail interdisciplinaire, associant génétique, agronomie, malherbologie, écologie et sociologie s'est constitué à l'occasion de la réponse à l'appel d'offre CIAB et au cours de la premiÚre phase de fonctionnemet qui est présenté ici. Malgré certaines lacunes ou faiblesses dans la construction interdiciplinaire, les résultats font entrevoir des perspectives prometteuses,dans un contexte plus favorable, à condition que les partenariats scientifiques et professionnles soient renforcés

    Development of double porous poly (Δ - caprolactone)/chitosan polymer as tissue engineering scaffold

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    Polymer blend made from poly( - caprolactone)/chitosan (PCL/CHT) offers interesting opportunities for biological applications. The paper presents a new way to fabricate PCL/CHT double-porosity (macrovoids with interconnected microporosity) membrane materials from a chemical optimization of the solvent and non-solvent phases and from a modified phase inversion technique. By varying the PCL/CHT proportion, it is shown that it is possible to improve the chemical and physical properties of the CHT carbohydrate polymer. The PCL/CHT membranes are fully characterized in term of physico-chemical properties (ATR-FTIR, XRD and DSC) to understand the miscibility of the two-polymer blend. Morphological characterization by SEM shows that by increasing CHT wt% in the blend, the size of the macrovoids was increasing. Rapid enzymatic degradation of PCL from all the blend was found by using lipase (from P. cepacia). The mechanisms at the origin of the morphological structuration of the material is also discussed. To test the ability to operate these materials as small diameter vascular scaffolds, cell culture with human umbilical vein endothelial cells (HUVECs) were carried out on the membrane and the results analyzed with laser scanning confocal microscopy (LSCM). Data suggest that the blend membrane with higher concentration of CHT polymer wt% have suitable properties that promote high number of cells on the surface by maintaining cellular cytoskeleton integrity within 3 days. The blend membrane with a double porous morphology could be potentially applicable in future for small diameter vascular graft application. The surface macrovoids (20–90â€ŻÎŒm) could be useful for three-dimensional cellular adhesion and proliferation and interconnected microporous spongy network (7–20â€ŻÎŒm) is expected to transfer essential nutrients, oxygen, growth factor between the macrovoids and the supernatant
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