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Efficacy of a single measurement of plasma anti-Müllerian hormone concentration for ovum pick-up donor selection of Japanese Black heifers in herd breeding programs
No full textIn this study, we evaluated the efficiency of a single measurement of plasma anti-Midlerian hormone (AMH) concentration in heifers in determining the number of oocytes recoverable by ovum pick-up (OPU), and compared AMH concentrations among sister heifers from the same parents. For this, blood samples from 50 embryo-transfer-derived female Japanese Black (JB) heifers (mean: 8.7 age in months) were collected and plasma AMH concentration was measured. At 13-15 months of age, both the number of follicles (2-9 mm) and the number of collected oocytes after OPU were counted and compared. Results indicated that the heifers with the highest AMH concentration had the highest number of follicles in their ovaries and gave the highest number of collected oocytes with OPU, thereby indicating that a single measurement of plasma AMH concentration is informative for the selection of OPU-donor heifers in herd breeding programs. The practice of performing a single AMH measurement may accelerate the intensive breeding of JB herds
Ingénierie de projet : 1. Conseils généraux avant de répondre à un appel à projet 2. Conseils pour répondre à un appel à projet
No full text« Manger autrement » dans le cadre de la transition agro-écologique Vers un système local de production et de consommation pour sécuriser l’alimentation en Guadeloupe ?
No full textCet article propose une réflexion sur la territorialisation de l’alimentation dans le cadre de la transition agro-écologique. Une étude de cas en Guadeloupe (un projet de création d’une usine d’agro-transformation visant à sécuriser l’alimentation) permet d’analyser les systèmes de représentations du premier cercle d’acteurs concernés par ce dispositif d’action publique : des agriculteurs et des acteurs institutionnels. Les résultats montrent que ces représentations sont difficilement conciliables et risquent de conduire à des mécanismes d’exclusion sociale et de non écologisation de l’agriculture.This article deals with food territorialization process in the context of the agro-ecological transition. From an empirical investigation based on a case study in Guadeloupe (creation of an agro-processing factory in order to secure food), we analyze the representations and values of a range of stakeholders: farmers and institutional actors. The results show that these representations and values systems are difficult to reconcile and may lead not only to mechanisms of social exclusion but also to the non-ecologisation of agriculture
La phytosociologie au service de l'agroécologie : exemple des "prairies humides" de Midi Pyrénées
No full textPour faire passer l’agroécologie de la théorie à la pratique de terrain sur les prairies permanentes de Midi-Pyrénées, le Conservatoire botanique national des Pyrénées et de Midi-Pyrénées et l’INRA-Agir proposent des indices de mesure des qualités agronomiques et écologiques de ces végétations. Après avoir constitué une base de données de relevés phytosociologiques et d’enquêtes de pratique sur plus de 500 parcelles, le travail proposé ici est de mesurer l’apport de ces indices dans la compréhension des enjeux agroécologiques des prairies humides. Les prairies humides se révèlent ainsi disposer de réelles qualités à valoriser au sein des exploitations agricoles. La productivité, la souplesse d’exploitation, la précocité, la présence de refus, la spécialisation écologique, la présence d’espèces rares sont autant d’éléments dont les indices pro-posés ici tirent une mesure mathématique construite sur la base de données. Ces indices fournissent des éléments de diagnostic et de dialogue entre les agronomes, les naturalistes, les gestionnaires de territoires et les agriculteurs.To move agroecology from theory to field practice on the permanent grasslands of Midi-Pyrénées, the Conservatoire botanique national des Pyrénées et de Midi-Pyrénées and INRA-Agir propose indices to measure the agronomic and ecological qualities of these vegetations. After having compiled a database of phytosociological surveys and practice surveys on more than 500 plots, the work proposed here is to measure the contribution of these indices to the understanding of agroecological issue in wet grasslands. Wet grasslands are thus proving to have real qualities to enhance on farms. Productivity, flexibility of exploitation, early maturity, presence of refusal, ecological specialisation, presence of rare species are all elements from which the indices proposed here draw a mathematical measure built on the database. These indices provide elements for diagnosis and dialogue between agronomists, naturalists, land managers and farmers
Effet du greffage et d’agents de biocontrôle pour protéger la tomate contre Botrytis cinerea
No full textBotrytis cinerea est un champignon pathogène de plus de 200 espèces végétales. Parmi elles, beaucoup sont des espèces cultivées; la tomate en fait partie. La lutte chimique contre ce pathogène est compliquée puisque des résistances à la plupart des fongicides utilisés sont apparues. Néanmoins il existe de nombreuses méthodes de lutte alternatives. Les agents de biocontrôle en font partie. Le greffage est très répandu en culture de tomate sous serre, notamment pour son effet protecteur contre certains pathogènes telluriques. Cependant, aucune information n’existe sur un effet bénéfique potentiel du greffage de la tomate contre des parasites aériens tels que B. cinerea, utilisé seul ou en combinaison avec l’application d’agents de biocontrôle. [br/]
Ces effets ont été étudiés dans le cadre du projet européen « EUCLID », pour une variété de tomate (Clodano), greffée sur elle-même ou sur une variété porte-greffe classique (Emperador), en combinaison avec quatre agents de biocontrôle (Regalia, Prestop, Serenade et un produit issu du projet EUCLID). Le greffage n’a montré aucun effet protecteur direct contre B. cinerea chez la tomate et il n’a pas affecté l’efficacité protectrice des produits Serenade et Regalia. Par contre une réduction de protection, faible (<2%) mais statistiquement significative, a été observée sur les plants greffés traités avec le produit Prestop et le produit issu du projet EUCLID.The fungus Botrytis cinerea is pathogenic on more than 200 plant species. Many of which are cultivated; tomato is one of them. Chemical control of B. cinerea is complicated by the appearance of resistances against the majority of registered fungicides. However a lot of alternative methods already exist, including the use of biocontrol agents. Grafting is a commonly used in greenhouse tomato production, as it provides a good level of protection against certain soil-borne pathogens. However, there is no information on its potential protective effect against air-borne pathogens such as B. cinerea or on possible interference with the protective effect of treatments with biocontrol agents. [br/]
These effects were investigated in the context of the « EUCLID » European project, for a commercial tomato variety (Clodano) grafted on itself or on a commonly used rootstock variety (Emperador), in combination with the application of four biocontrol agent efficiencies (Regalia, Prestop, Serenade and a product developed within the EUCLID project). Grafting provided no direct protective effect against B. cinerea and it did not alter the efficiency of Serenade and Regalia. However, a small (<2%) but statistically significant reduction in the protective effect was observed for Prestop and the EUCLID product
Embolism resistance in petioles and leaflets of palms
No full textHydraulic studies are currently biased towards conifers and dicotyledonous angiosperms; responses of arborescent monocots to increasing temperature and drought remain poorly known. This study aims to assess xylem resistance to drought-induced embolism in palms.We quantified embolism resistance via P50 (xylem pressure inducing 50 % embolism or loss of hydraulic conductivity) in petioles and leaflets of six palm species differing in habitat and phylogenetic relatedness using three techniques: in vivo X-ray-based microcomputed tomography, the in situ flow centrifuge technique and the optical vulnerability method.Our results show that P50 of petioles varies greatly in the palm family, from −2.2 ± 0.4 MPa in Dypsis baronii to −5.8 ± 0.3 MPa in Rhapis excelsa (mean ± s.e.). No difference or weak differences were found between petioles and leaf blades within species. Surprisingly, where differences occurred, leaflets were less vulnerable to embolism than petioles. Embolism resistance was not correlated with conduit size (r = 0.37, P = 0.11).This study represents the first estimate of drought-induced xylem embolism in palms across biomes and provides the first step towards understanding hydraulic adaptations in long-lived arborescent monocots. It showed an almost 3-fold range of embolism resistance between palm species, as large as that reported in all angiosperms. We found little evidence for hydraulic segmentation between leaflets and petioles in palms, suggesting that when it happens, hydraulic segregation may lack a clear relationship with organ cost or replaceability
Is there a role for glutaredoxins and BOLAs in the perception of the cellular iron status in plants?
No full textGlutaredoxins (GRXs) have at least three major identified functions. In apoforms, they exhibit oxidoreductase activity controlling notably protein glutathionylation/deglutathionylation. In holoforms, i.e., iron-sulfur (Fe-S) cluster-bridging forms, they act as maturation factors for the biogenesis of Fe-S proteins or as regulators of iron homeostasis contributing directly or indirectly to the sensing of cellular iron status and/or distribution. The latter functions seem intimately connected with the capacity of specific GRXs to form [2Fe-2S] cluster-bridging homodimeric or heterodimeric complexes with BOLA proteins. In yeast species, both proteins modulate the localization and/or activity of transcription factors regulating genes coding for proteins involved in iron uptake and intracellular sequestration in response notably to iron deficiency. Whereas vertebrate GRX and BOLA isoforms may display similar functions, the involved partner proteins are different. We perform here a critical evaluation of the results supporting the implication of both protein families in similar signaling pathways in plants and provide ideas and experimental strategies to delineate further their functions
A role for auxin signaling in the acquisition of longevity during seed maturation
No full text1. Seed longevity, the maintenance of viability during dry storage, is a crucial factor to preserve plant genetic resources and seed vigor. Inference of a temporal gene-regulatory network of seed maturation identified auxin signaling as a putative mechanism to induce longevity-related genes.
2. Using auxin-response sensors and tryptophan-dependent auxin biosynthesis mutants of Arabidopsis thaliana L., the role of auxin signaling in longevity was studied during seed maturation.
3. DII and DR5 sensors demonstrated that concomitant with the acquisition of longevity, auxin signaling input and output increased and underwent a spatio-temporal redistribution, spreading throughout the embryo. Longevity of seeds of single auxin biosynthesis mutants with altered auxin signaling activity was affected in a dose-response manner depending on the level of auxin activity. Longevity-associated genes with promoters enriched in auxin response elements and the master regulator ABSCISIC ACID INSENSITIVE 3 were induced by auxin in developing embryos and deregulated in auxin biosynthesis mutants. The beneficial effect of exogenous auxin during seed maturation on seed longevity was abolished in abi3-1 mutants.
4. These data suggest a role for auxin signaling activity in the acquisition of longevity during seed maturation
Measuring the pulse of trees; using the vascular system to predict tree mortality in the 21st century
No full textTree mortality during hot and dry conditions presents a stark reminder of the vulnerability of plant species to climatic extremes. The current global warming trend makes predicting the impacts of hot/dry events on species survival an urgent task; yet, the standard tools for this purpose lack a physiological basis. This review examines a diversity of recent evidence demonstrating how physiological attributes of plant vascular systems can explain not only why trees die during drought, but also their distributional limits according to rainfall. These important advances in the science of plant water transport physiology provide the basis for new hydraulic models that can provide credible predictions of not only how but when, where and which species will be impacted by changes in rainfall and temperature in the future. Applying a recently developed hydraulic model using realistic parameters, we show that even apparently safe mesic forest in central France is predicted to experience major forest mortality before the end of the century