eKhSACIR інституційному репозитарії Харківської державної академії культури
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Wind-resistance strategies of trees: effects of size and material properties
No full textInternational audienc
Lactate Plays a Key Role in the Crosstalk Between Streptococcus thermophilus and Colonic Epithelium in Gnotobiotic Rats
No full textInternational audienc
Reverse modeling enables estimating yield losses caused by individual and multiple disease injuries
No full textInternational audienceYield loss analyses are critical to inform tactical and strategic decisions for crop health management. Yield loss measurement requires the quantification of (1) levels of injury caused by disease or pest, (2) actual (injured) yield, and (3) attainable (un-injured) yield. Reverse modelling allows reconstructing an object or a process from limited information combined with a mathematical model. We reconstructed attainable yields and derived yield losses caused by diseases in winter wheat using a simulation model (WHEATPEST) combined with field data generated by a network of experiments across France, where disease injuries and actual yields, but not attainable yields, were measured. The analysis covered 70 [Year x Region x Variety x Crop Management] combinations, from 2004 to 2008. In each combination, three simulation steps were taken in order to model: (1) actual yields, (2) attainable yields, and (3) yield losses associated with individual diseases. Simulated overall yield losses from combined diseases ranged from 0 to 4.2 t ha–1, and averaged 0.80 t ha–1. Septoria tritici blotch caused the highest mean yield loss of 0.66 t ha–1. Other diseases causing losses, in decreasing order, were FHB, leaf rust, stripe rust, and powdery mildew. The results highlight the contribution of varietal improvement to agricultural sustainability. Reverse modelling can be applied to other crops and diseases or pests, in order to estimate individual and combined diseases yield losses
Contribution of vegetation (trees and ground vegetation) on the methane budget of a temperate forest
No full textMethane (CH4) is one the most important greenhouse gas and is responsible for approximatively 20% of the global warming (IPCC, 2013). Soils and mainly upland forest soils where aerobic environment prevails, are one of the main global sink of methane (IPCC 2013). At the soil-atmosphere interface, the net methane efflux consists in a net balance between the production of CH4 by methanogenic bacteria mainly in deep anaerobic soil layers and the consumption by methanotrophic bacteria in the aerobic soil horizons of the methane produced in the soil or diffusing from the atmosphere into the soil. In upland forest, some episodic temporary waterlogging may exist, especially in managed forest where trafficked work on silty or clayey soils compacts the soil and then, enhanced the waterlogging (Startsev and McNabb, 2000). But the methane budget of ecosystem may be improved when considering not only soil but also plant compartments. Plants can impact the CH4 production and consumption by different pathways (enhance production, consumption, and/or gases transport). When the soil is submitted to compaction and then, to an increase of waterlogging, the ground vegetation is modified in favor of vegetation with aerenchymous tissues (Goutal-Pousse et al, 2012) and the soil can shift from a methane sink to an episodic methane source (Epron et al 2016). In the present study, our objectives were to determine (i) if vegetation emits CH4, (ii) if abiotic factors drive the seasonal CH4 flux pattern by plants (ground vegetation and trees) and (iii) to quantify the impact of the emissions by vegetation (tree and ground vegetation) on the methane budget of a forest submitted to compaction. We hypothesized that in an upland forest, vegetation (ground vegetation and tree stems) by enhancing the CH4 emission or by producing CH4 may reduce the methane sink of the forest ecosystem. This study was carried out in a 6-ha experimental site set up in 2007 in the state-owned forest of "les Hauts Bois" (north-eastern France) to assess the long-term impact of a loaded forwarder. To study this effect, the soil was compacted before afforestation. We recorded CH4 fluxes during 7 months at a 3-hour frequency using automated chambers on stem tree, bare soil and soil with vegetation, connected to a laser-based gas analyser in a forest site where the ground-vegetation consists mainly in two aerenchymous plants (glyceria striata and juncus sp) and trees in planted Quercus petraea. In contradiction with our hypothesis and previous studies, in this studied site, the presence of ground vegetation increases the methane forest ecosystem uptake compared to the bare soil but with an impact varying during the season. In addition, the increase in the methane uptake depended on the species, from 80 % to 120%. Methane emission by tree stem were low compared to methane uptake by soil (-3.6 ± 0.4 kg ha-1 and 0.90 ± 0.31 g ha-1 respectively) but methane emission by stem was enhanced when methane was produced into the soil
Diversity analysis within a collection of 1191 flint maize inbred lines using genotyping-by-sequencing
No full textNational audienceGenotyping-by-sequencing (GBS) is a highly cost-effective procedure that permits the analysis of large collections of inbred lines. We used it to characterize diversity in 1191 maize flint inbred lines from the INRA collection, the European Cornfed-Flint association panel, and flint lines recently derived from landraces. We analyzed the properties of GBS data obtained with different imputation methods, by comparison with a 50K SNP array. We identified 7 ancestral groups within the Flint collection (five typically flint: Northern Flint, Italy, Pyrenees-Galicia, Argentina, Lacaune, and also Dent and Pop corn) that are in agreement with breeding knowledge. This analysis highlighted that many lines are issued from crosses between different flint ancestral groups (admixture). Approximately 200 lines also appear to be issued from crosses with dent germplasm aiming at the improvement of flint germplasm. We performed association studies on different agronomic traits, revealing SNPs associated with cob color, kernel color, and male flowering time variation. We analyzed the relationship between the haplotype diversity and the trait variation at some strong association peaks
L’élevage de précision, quels changements dans la relation homme-animal et la représentation de leur métier par les éleveurs ?
No full textNational audienc
RNA-Seq showed that lactation modified gene expression profile in goat adipose tissue
No full textSession 4: Nutrition to improve milk and meat qualityNational audienc
Etude de la mise en place d’une évaluation génétique des bovins allaitants de l’île de la Réunion
No full textNational audienceL’île de la Réunion présente des caractéristiques climatiques (climat tropical soumis aux alizés), topographiques (zones d’élevage réparties entre 0 et 2400 m d’altitude sur seulement 2 512 km² (figure1)) et une composition du cheptel différentes de celles de la métropole (forte utilisation du croisement). Or, depuis 1996, un contrôle des performances au sevrage a été mis en place en ferme, selon le protocole pratiqué pour les évaluations nationales des bovins allaitants. L’objectif de cette étude a donc été la valorisation des données collectées en vue de la mise en place d’une évaluation génétique des bovins allaitants de la Réunion
Earthworms affect biogeochemical cycling through their impact on carbon and nitrogen stabilization by mineral interactions
No full textInternational audienceStabilization of organic matter (OM) is an important process controlling the coupling and decoupling of biogeochemical cycles and their role in mitigating climate change. Soil organisms, particularly earthworms, may greatly influence these processes through their potential impact on the interaction of OM with soil minerals ; a mechanism which may protect soil organic matter (SOM) at medium (years) and long (decades, centuries) time scales. The aim of this study was to use earthworms and pure minerals in order to enhance the formation of organo mineral interactions during a 6 month decomposition experiment. Our experimental approach was based on the comparison of OM decomposition without minerals and OM decomposition with minerals (70% fresh OM & 30% Montmorillonite). These treatments were establish with and without the simultaneous presence of two epigeic earthworm species (Eisenia andrei and Eisenia foetida). We used density fractionation of the end-products to isolate several fractions : water soluble OM, free particulate OM, mineral associated OM (>1.6 g cm3 and >1.8 g cm3). The fractions were characterised by elemental analyses, electron microscopy and Rock Eval pyrolyses to investigate the effect of earthworms on the allocation of C and N compared to treatments without worms. Presence of minerals led to the formation of organo-mineral complexes in the heavy fractions, while for pure OM treatments heavy fractions were absent. Indeed, the addition of minerals during the decomposition process resulted in the transfert of 70% of carbon and nitrogen from soluble and particulate OM to heavy fractions. With worms more C and N were allocated to the >1.8 g cm3 fractions as compared to treatments without worms. Indeed, worms led to highest C contribution in the 1.6-1.8 g cm3 fraction. Moreover, earthworm presence led to the formation of black cristalline particles in the heaviest fraction. Information about the morphology and stability of organo-mineral complexes will be presented. We conclude that the presence of earthworms impact biogeochemical cycling of C and N through influencing the stabilization of OM by interaction with minerals