Virtual modeling based on deep phenotyping provides complementary data to field experiments to predict plant emergence in oilseed rape genotypes

International audienceBreeding oilseed rape for oil and protein contents may have led to differences in seedling emergence in genotypes. New opportunities for deep automated phenotyping of germination and seedling growth are being developed on phenotyping platforms. Our aim was to demonstrate that using these data to parameterize a crop emergence model complements field experiments for the evaluation of differences among genotypes. Five genotypes, chosen in a diverse set of winter oilseed rape for their different germination speeds, were phenotyped for germination at different temperatures and water potentials as well as for radicle and hypocotyl growth. These data were used as parameters to run the SIMPLE crop emergence model over a period of 27 years (1985–2012), at two locations, one in France and one in Germany, and at four sowing dates. Field experiments were performed in 2012, 2013 and 2014, and the emergence of the five genotypes was measured at early and late sowing dates. First, model predictions were compared with observed field emergence in the French sowing trials in 2014. The model proved to be rather good at predicting the emergence of the genotypes. Then, for the simulation study, the model extended the observed differences between locations and sowing dates over a greater number of years. The model also identified the main reasons for non-emerging seedlings and their frequencies in the simulated sowings. Differences between the five genotypes were on average very small, but complex interactions appeared that led to bigger differences under certain sowing conditions. This study demonstrates that combining deep phenotyping with crop models in simulation studies paves the way for more precise and detailed evaluation of genotype

Personal exposure of children and adults to airborne benzene in four French cities

International audienceAtmospheric concentrations of and personal exposure to benzene have been measured in four French metropolitan areas for 210 subjects over two seasons. Half of the volunteers were 6-13-year-old children. The adult subjects were nonsmokers, not occupationally exposed and they live and work in the monitored areas. Measurements were performed using diffusive samplers followed by GC-FID analysis. The average values for ambient air concentrations (mu gm(-3)) were: Rouen: 1.5; Ile de France (Paris area): 1.6; Grenoble: 2.3 and Strasbourg: 2.6, showing that benzene concentrations in the ambient air of the four cities satisfy the requirements of the European Directive 2000/69 EC of the European Parliament which stipulates a limit value of 5 mu gm(-3). However, the 48h exposures measured were found to be between 2.7 and 3.5 times higher than ambient air concentrations. As a consequence, 60% of the subjects investigated, including children, were exposed to concentrations higher than the ambient air limit value. This work confirms that air monitoring data collected by fixed stations should be used with caution when assessing population exposure to benzene, especially given the influence of indoor sources and other polluted microenvironments where people spend part of their time

A local score approach improves GWAS resolution and detects minor QTL: application to Medicago truncatula quantitative disease resistance to multiple Aphanomyces euteiches isolates

International audienceQuantitative trait loci (QTL) with small effects, which are pervasive in quantitative phenotypic variation, are difficult to detect in genome-wide association studies (GWAS). To improve their detection, we propose to use a local score approach that accounts for the surrounding signal due to linkage disequilibrium, by accumulating association signals from contiguous single markers. Simulations revealed that, in a GWAS context with high marker density, the local score approach outperforms single SNP p-value-based tests for detecting minor QTL (heritability of 5-10%) and is competitive with regard to alternative methods, which also aggregate p-values. Using more than five million SNPs, this approach was applied to identify loci involved in Quantitative Disease Resistance (QDR) to different isolates of the plant root rot pathogen Aphanomyces euteiches, from a GWAS performed on a collection of 174 accessions of the model legume Medicago truncatula. We refined the position of a previously reported major locus, underlying MYB/NB-ARC/tyrosine kinase candidate genes conferring resistance to two closely related A. euteiches isolates belonging to pea pathotype I. We also discovered a diversity of minor resistance QTL, not detected using p-value-based tests, some of which being putatively shared in response to pea (pathotype I and III) and/or alfalfa (race 1 and 2) isolates. Candidate genes underlying these QTL suggest pathogen effector recognition and plant proteasome as key functions associated with M. truncatula resistance to A. euteiches. GWAS on any organism can benefit from the local score approach to uncover many weak-effect QTL

Genetic control of yield and yield components in winter oilseed rape ([i]Brassica napus[/i] L.) grown under nitrogen limitation

International audienceDespite its high nitrogen absorption capacity, oilseed rape (OSR) has a low apparent nitrogen use efficiency (NUE), which makes its production highly dependent on nitrogen fertilization. Improving NUE in OSR is therefore a main target in breeding. The objectives of the present work were to determine the genomic regions (QTLs) associated with yield and to assess their stability under contrasted nitrogen nutrition regimes. One mapping population, AM, was tested in a French location for three growing seasons (2011, 2012 and 2013), under two nitrogen conditions (optimal and low). Eight yield-related traits were scored and nitrogen-responsive traits were calculated. A total of 104 QTLs were detected of which 28 controlled flowering time and 76 were related to yield and yield components. Very few genotype x nitrogen interactions were detected and the QTLs were highly stable between the nitrogen conditions. In contrast, only a few QTLs were stable across the years of the trial, suggesting a strong QTL x year interaction. Finally, eleven critical genomic regions that were stable across nitrogen conditions and/or trial years were identified. One particular region located on the A5 linkage group appears to be a promising candidate for marker assisted selection programs. The different strategies for OSR breeding using the QTLs found in the present study are discusse

Incidence of four genera of fungi in organic and low-input farming conditions in/on the grain of bread wheat over a 13-year period in France

International audienceBread wheat can be infected and/or contaminated by several genera of mycotoxin-producing fungi. In the European Union, several mycotoxins are subject to defined limits for human consumption. Speculation has arisen about the potential higher contamination level of mycotoxins produced by Fusarium species in organic compared to conventional production systems. So far, many studies have focused on the level of mycotoxins, highlighting comparable levels in organic and conventional farming. In this long-term study, we monitored, each year over a 13-year period in several sites in France and for a set of bread wheat genotypes, the incidence of four fungal genera on bread wheat grains from both conventional low-input and organic farming. During this long period of monitoring, we used the same morphological characterization of fungal colonies. The results obtained highlighted two general trends. First, the incidence of the genus Fusarium in grains was generally lower than or equal to 1% in more than 60% of “year × site” combinations, both in low-input and organic farming conditions. In contrast, the genus Alternaria was dominant in the vast majority of combinations. Second, the main explanatory factors of the incidence of fungus on grains, independently of the genus and the farming conditions, were the year and the “year × site” interaction, suggesting the dominant influence of the environmental conditions of the year and the site on the relative development of the fungal genera in/on grains. According to these results, organic or low-input production of bread wheat does not represent a significant risk for the development of Fusarium head blight in France

Low Incidence Of Fusarium In Organic Farming On Bread Wheat Grains Over A 13-Year Period

Organic farming has been questioned about its ability to manage Fusarium infestation compared with conventional farming. In this study, we monitored, over a 13-year period in several sites in France, the fungal incidence of four genera of fungi on bread wheat grains from organic farming. We collected samples immediately after harvest in conditions of natural contamination on a list of winter wheat varieties from 2006 to 2018 in several sites in France. From each sample, 100 kernels were surface disinfected, plated on potato dextrose agar, and colonies were identified at the genus level, and at the species level for Fusarium graminearum. The fungal incidence observed on kernels over the period was on average 88 ± 16% (i.e. mean ± standard-deviation). Kernels were mainly infected by fungal species of the genus Alternaria (71 ± 25%), while the incidence of Fusarium graminearum is usually very low in our context (1 ± 2%), with the exception of year 2008 (49 ± 12% and 17 ± 9%, respectively in the two sites studied), which is confirmed by the highly significant effect of the year and the ‘year × site’ interaction. To conclude, in our study, Fusarium graminearum appeared not to be a major concern for wheat production in organic farming systems

Les inégalités de santé en Guyane : état des lieux et préconisations

Le Haut Conseil de la santé publique a dressé un état des lieux des principaux facteurs contribuant aux inégalités de santé en Guyane, en lien avec les caractéristiques sociales, ethniques, géographiques, environnementales et culturelles de cette région.Sept grands domaines de risques pour la santé des populations sont considérés :l’accès à l’eau de boisson et l’assainissement ;les intoxications et intoxinations environnementales ;l’alimentation et la nutrition ;la santé sexuelle, la santé reproductive et l’égalité entre les genres ;la santé mentale ;les risques infectieux ;les accidents de la route.Au-delà d’une analyse thématique segmentée, le HCSP a également appréhendé ces domaines et leurs déterminants de manière systémique pour mettre en lumière leurs interactions.Les informations et données synthétisées à cet effet proviennent de la littérature scientifique et des nombreux rapports consultés sur les sites des organismes compétents en Guyane et hors Guyane, de l’audition de personnalités ayant exercé ou exerçant sur le territoire, et de rencontres sur place avec des acteurs locaux lors d’une mission d’une délégation du HCSP.Sur cette base, le HCSP formule un ensemble de 61 préconisations regroupées en deux grandes catégories :Préconisations « stratégiques » relatives au cadre institutionnel, partenarial ou informationnel facilitant le déploiement de politiques ou d’actions ayant un impact significatif en termes de santé publique ;Préconisations « opérationnelles » à objectifs ciblés.Cette expertise transversale des principaux enjeux de santé sur le territoire de la Guyane fait suite à une saisine de la Direction générale de la santé de 2018

Les inégalités de santé en Guyane : état des lieux et préconisations

Le Haut Conseil de la santé publique a dressé un état des lieux des principaux facteurs contribuant aux inégalités de santé en Guyane, en lien avec les caractéristiques sociales, ethniques, géographiques, environnementales et culturelles de cette région.Sept grands domaines de risques pour la santé des populations sont considérés :l’accès à l’eau de boisson et l’assainissement ;les intoxications et intoxinations environnementales ;l’alimentation et la nutrition ;la santé sexuelle, la santé reproductive et l’égalité entre les genres ;la santé mentale ;les risques infectieux ;les accidents de la route.Au-delà d’une analyse thématique segmentée, le HCSP a également appréhendé ces domaines et leurs déterminants de manière systémique pour mettre en lumière leurs interactions.Les informations et données synthétisées à cet effet proviennent de la littérature scientifique et des nombreux rapports consultés sur les sites des organismes compétents en Guyane et hors Guyane, de l’audition de personnalités ayant exercé ou exerçant sur le territoire, et de rencontres sur place avec des acteurs locaux lors d’une mission d’une délégation du HCSP.Sur cette base, le HCSP formule un ensemble de 61 préconisations regroupées en deux grandes catégories :Préconisations « stratégiques » relatives au cadre institutionnel, partenarial ou informationnel facilitant le déploiement de politiques ou d’actions ayant un impact significatif en termes de santé publique ;Préconisations « opérationnelles » à objectifs ciblés.Cette expertise transversale des principaux enjeux de santé sur le territoire de la Guyane fait suite à une saisine de la Direction générale de la santé de 2018

Les inégalités de santé en Guyane : état des lieux et préconisations

Le Haut Conseil de la santé publique a dressé un état des lieux des principaux facteurs contribuant aux inégalités de santé en Guyane, en lien avec les caractéristiques sociales, ethniques, géographiques, environnementales et culturelles de cette région.Sept grands domaines de risques pour la santé des populations sont considérés :l’accès à l’eau de boisson et l’assainissement ;les intoxications et intoxinations environnementales ;l’alimentation et la nutrition ;la santé sexuelle, la santé reproductive et l’égalité entre les genres ;la santé mentale ;les risques infectieux ;les accidents de la route.Au-delà d’une analyse thématique segmentée, le HCSP a également appréhendé ces domaines et leurs déterminants de manière systémique pour mettre en lumière leurs interactions.Les informations et données synthétisées à cet effet proviennent de la littérature scientifique et des nombreux rapports consultés sur les sites des organismes compétents en Guyane et hors Guyane, de l’audition de personnalités ayant exercé ou exerçant sur le territoire, et de rencontres sur place avec des acteurs locaux lors d’une mission d’une délégation du HCSP.Sur cette base, le HCSP formule un ensemble de 61 préconisations regroupées en deux grandes catégories :Préconisations « stratégiques » relatives au cadre institutionnel, partenarial ou informationnel facilitant le déploiement de politiques ou d’actions ayant un impact significatif en termes de santé publique ;Préconisations « opérationnelles » à objectifs ciblés.Cette expertise transversale des principaux enjeux de santé sur le territoire de la Guyane fait suite à une saisine de la Direction générale de la santé de 2018