Dussert Y.,CNRS Ecology, Systematic and Evolution Laboratory
Heredity | Year: 2017
Despite of a growing interest in considering the role of sociological factors in seed exchanges and their consequences on the evolutionary dynamics of agro-biodiversity, very few studies assessed the link between ethno-linguistic diversity and genetic diversity patterns in small-holder farming systems. This is key for optimal improvement and conservation of crop genetic resources. Here, we investigated genetic diversity at 17 SSR markers of pearl millet landraces (varieties named by farmers) in the Lake Chad Basin. 69 pearl millet populations, representing 27 landraces collected in eight ethno-linguistic farmer groups, were analyzed. We found that the farmers’ local taxonomy was not a good proxy for population’s genetic differentiation as previously shown at smaller scales. Our results show the existence of a genetic structure of pearl millet mainly associated with ethno-linguistic diversity in the western side of the lake Chad. It suggests there is a limit to gene flow between landraces grown by different ethno-linguistic groups. This result was rather unexpected, because of the highly outcrossing mating system of pearl millet, the high density of pearl millet fields all along the green belt of this Sahelian area and the fact that seed exchanges among ethno-linguistic groups are known to occur. In the eastern side of the Lake, the pattern of genetic diversity suggests a larger efficient circulation of pearl millet genes between ethno-linguistic groups that are less numerous, spatially intermixed and, for some of them, more prone to exogamy. Finally, other historical and environmental factors which may contribute to the observed diversity patterns are discussed.Heredity advance online publication, 25 January 2017; doi:10.1038/hdy.2016.128. © 2017 The Author(s)
Corbel S.,French National Institute for Agricultural Research |
Mougin C.,French National Institute for Agricultural Research |
Bouaicha N.,CNRS Ecology, Systematic and Evolution Laboratory
Chemosphere | Year: 2014
The occurrence of harmful cyanobacterial blooms in surface waters is often accompanied by the production of a variety of cyanotoxins. These toxins are designed to target in humans and animals specific organs on which they act: hepatotoxins (liver), neurotoxins (nervous system), cytotoxic alkaloids, and dermatotoxins (skin), but they often have important side effects too. When introduced into the soil ecosystem by spray irrigation of crops they may affect the same molecular pathways in plants having identical or similar target organs, tissues, cells or biomolecules. There are also several indications that terrestrial plants, including food crop plants, can bioaccumulate cyanotoxins and present, therefore, potential health hazards for human and animals. The number of publications concerned with phytotoxic effects of cyanotoxins on agricultural plants has increased recently. In this review, we first examine different cyanotoxins and their modes of actions in humans and mammals and occurrence of target biomolecules in vegetable organisms. Then we present environmental concentrations of cyanotoxins in freshwaters and their fate in aquatic and soil ecosystems. Finally, we highlight bioaccumulation of cyanotoxins in plants used for feed and food and its consequences on animals and human health. Overall, our review shows that the information on the effects of cyanotoxins on non-target organisms in the terrestrial environment is particularly scarce, and that there are still serious gaps in the knowledge about the fate in the soil ecosystems and phytotoxicity of these toxins. © 2013 Elsevier Ltd.
Garamszegi L.Z.,CSIC - Doñana Biological Station |
Moller A.P.,CNRS Ecology, Systematic and Evolution Laboratory |
Moller A.P.,Center for Advanced Study
Biological Reviews | Year: 2010
Comparative analyses aim to explain interspecific variation in phenotype among taxa. In this context, phylogenetic approaches are generally applied to control for similarity due to common descent, because such phylogenetic relationships can produce spurious similarity in phenotypes (known as phylogenetic inertia or bias). On the other hand, these analyses largely ignore potential biases due to within-species variation. Phylogenetic comparative studies inherently assume that species-specific means from intraspecific samples of modest sample size are biologically meaningful. However, within-species variation is often significant, because measurement errors, within- and between-individual variation, seasonal fluctuations, and differences among populations can all reduce the repeatability of a trait. Although simulations revealed that low repeatability can increase the type I error in a phylogenetic study, researchers only exercise great care in accounting for similarity in phenotype due to common phylogenetic descent, while problems posed by intraspecific variation are usually neglected. A meta-analysis of 194 comparative analyses all adjusting for similarity due to common phylogenetic descent revealed that only a few studies reported intraspecific repeatabilities, and hardly any considered or partially dealt with errors arising from intraspecific variation. This is intriguing, because the meta-analytic data suggest that the effect of heterogeneous sampling can be as important as phylogenetic bias, and thus they should be equally controlled in comparative studies. We provide recommendations about how to handle such effects of heterogeneous sampling. © 2010 The Author. Biological Reviews © 2010 Cambridge Philosophical Society.
Siljak-Yakovlev S.,CNRS Ecology, Systematic and Evolution Laboratory |
Peruzzi L.,University of Pisa
Plant Biosystems | Year: 2012
Following an overview of the classification scheme for endemic species, the authors propose to complement it based on modern molecular cytogenetic techniques. Molecular cytogenetics provides new possibilities in the study of chromosomal evolution and genome organization, and contributes to a better characterization of the karyotype of endemic species. Through several examples, the authors demonstrate the advantages of molecular cytogenetic techniques in resolving relationships between endemic and related species, leading to a more precise categorisation, especially in the absence of polyploidy. The authors recommend some caution in the interpretation of cytogenetic data alone, and stress the importance of comparing cytogenetic results with those obtained from independent sources (i.e., molecular phylogenetics, phytogeography, ecology). Finally, the current classification of endemic species is revised in the light of molecular cytogenetics and other newly available evidence. © 2012 Copyright Taylor and Francis Group, LLC.
Moller A.P.,CNRS Ecology, Systematic and Evolution Laboratory |
Mousseau T.A.,University of South Carolina
Ecological Indicators | Year: 2013
To test whether radioactive contamination reduced the abundance of mammals, and whether species differed in susceptibility to radiation, we censused mammals by counting tracks in the snow along 161 100-m line transects around Chernobyl during February 2009. The abundance of mammal tracks was negatively related to level of background radiation, independent of the statistical model, with effects of radiation accounting for a third of the variance. The effect of radiation differed significantly among species. There was a positive relationship between abundance of predators and abundance of prey, modified by the level of background radiation because the number of predators increased disproportionately with the number of prey at high levels of radiation. These findings suggest that predatory mammals aggregate in areas with abundant prey, especially when prey are exposed to high levels of radiation. This study emphasizes the negative effects of level of background radiation on the abundance of mammals and predator-prey interactions. © 2012 Elsevier Ltd. All rights reserved.
Dunn P.O.,University of Wisconsin - Milwaukee |
Moller A.P.,CNRS Ecology, Systematic and Evolution Laboratory
Journal of Animal Ecology | Year: 2014
Although the phenology of numerous organisms has advanced significantly in response to recent climate change, the life-history and population consequences of earlier reproduction remain poorly understood. We analysed extensive data on temporal change in laying date and clutch size of birds from Europe and North America to test whether these changes were related to recent trends in population size. Across studies, laying date advanced significantly, while clutch size did not change. However, within populations, changes in laying date and clutch size were positively correlated, implying that species which advanced their laying date the most were also those that increased their clutch size the most. Greater advances in laying date were associated with species that had multiple broods per season, lived in nonagricultural habitats and were herbivorous or predatory. The duration of the breeding season increased for multibrooded species and decreased for single-brooded species. Changes in laying date and clutch size were not related to changes in population size (for resident or migratory species). This suggests that, across a wide variety of species, mismatches in the timing of egg laying or numbers of offspring have had relatively little influence on population size compared with other aspects of phenology and life history. © 2013 British Ecological Society.
Horstkotte T.,Umeå University |
Roturier S.,CNRS Ecology, Systematic and Evolution Laboratory
Forest Ecology and Management | Year: 2013
The landscape in boreal Sweden is dominated by even-aged, single-layered forest monocultures and clear cuts. Few forest stands with a more complex, multi-layered structure remain as landscape elements. We studied the impact that different forest management regimes have on snow conditions and the metamorphosis of snow, and discuss how these factors may affect suitability for reindeer grazing.Over two winters, we recorded the development of snow depth and hardness in clear cuts and two different forest types, and their changes with weather events. In the forests, the dynamics of snow characteristics were analyzed in relation to stand structure and at the level of individual trees.There were no clear differences in snow characteristics between single-layered and multi-layered stands, although snow hardness was more variable in the latter. In single-layered stands, snow depth and hardness were spatially uniformly distributed in relation to stand characteristics. Contrastingly, the complex structure of multi-layered stands did influence snow depth significantly. However, hardness was highly heterogeneous in these stands. Due to the absence of tree effects, clear cuts had deeper but softer snow than forested stands, although hardness increased towards spring.Weather affected the metamorphosis of the snow blanket. The magnitude of the effects depended on both timing and severity of discrete weather events and forest structure, but generally weather had a greater influence on snow cover characteristics than forest structure per se. In their interaction with weather, different forest structures affect the snow and thus suitability as winter grazing area for reindeer. Reindeer herders, therefore, require diversity in the landscape in order to respond to such weather variations and their impact on grazing conditions. © 2012 Elsevier B.V.
Ricroch A.E.,Agro ParisTech |
Ricroch A.E.,CNRS Ecology, Systematic and Evolution Laboratory
New Biotechnology | Year: 2013
Despite the fact that a thorough, lengthy and costly evaluation of genetically engineered (GE) crop plants (including compositional analysis and toxicological tests) is imposed before marketing some European citizens remain sceptical of the safety of GE food and feed. In this context, are additional tests necessary? If so, what can we learn from them? To address these questions, we examined data from 60 recent high-throughput '-omics' comparisons between GE and non-GE crop lines and 17 recent long-term animal feeding studies (longer than the classical 90-day subchronic toxicological tests), as well as 16 multigenerational studies on animals. The '-omics' comparisons revealed that the genetic modification has less impact on plant gene expression and composition than that of conventional plant breeding. Moreover, environmental factors (such as field location, sampling time, or agricultural practices) have a greater impact than transgenesis. None of these '-omics' profiling studies has raised new safety concerns about GE varieties; neither did the long-term and multigenerational studies on animals. Therefore, there is no need to perform such long-term studies in a case-by-case approach, unless reasonable doubt still exists after conducting a 90-day feeding test. In addition, plant compositional analysis and '-omics' profiling do not indicate that toxicological tests should be mandatory. We discuss what complementary fundamental studies should be performed and how to choose the most efficient experimental design to assess risks associated with new GE traits. The possible need to update the current regulatory framework is discussed. © 2013 Elsevier B.V.
Bailly E.,CNRS Ecology, Systematic and Evolution Laboratory |
Levi Y.,CNRS Ecology, Systematic and Evolution Laboratory |
Karolak S.,CNRS Ecology, Systematic and Evolution Laboratory
Environmental Pollution | Year: 2013
The Polar Organic Chemical Integrative Sampler (POCIS) is a new tool for the sampling of organic pollutants in water. We tested this device for the monitoring of pharmaceuticals in hospital wastewater. After calibration, a field application was carried out in a French hospital for six pharmaceutical compounds (Atenolol, Prednisolone, Methylprednisolone, Sulfamethoxazole, Ofloxacin, Ketoprofen). POCIS were calibrated in tap water and wastewater in laboratory conditions close to relevant environmental conditions (temperature, flow velocity). Sampling rates (Rs) were determined and we observed a significant increase with flow velocity and temperature. Whatever the compound, the Rs value was lower in wastewater and the linear phase of uptake was shorter. POCIS were deployed in a hospital sewage pipe during four days and the estimated water concentrations were close to those obtained with twenty-four hour composite samples. © 2012 Elsevier B.V. All rights reserved.
Ben Ghozlen N.,CNRS Ecology, Systematic and Evolution Laboratory
Sensors (Basel, Switzerland) | Year: 2010
A new, commercial, fluorescence-based optical sensor for plant constituent assessment was recently introduced. This sensor, called the Multiplex(®) (FORCE-A, Orsay, France), was used to monitor grape maturation by specifically monitoring anthocyanin accumulation. We derived the empirical anthocyanin content calibration curves for Champagne red grape cultivars, and we also propose a general model for the influence of the proportion of red berries, skin anthocyanin content and berry size on Multiplex(®) indices. The Multiplex(®) was used on both berry samples in the laboratory and on intact clusters in the vineyard. We found that the inverted and log-transformed far-red fluorescence signal called the FERARI index, although sensitive to sample size and distance, is potentially the most widely applicable. The more robust indices, based on chlorophyll fluorescence excitation ratios, showed three ranges of dependence on anthocyanin content. We found that up to 0.16 mg cm(-2), equivalent to approximately 0.6 mg g(-1), all indices increase with accumulation of skin anthocyanin content. Excitation ratio-based indices decrease with anthocyanin accumulation beyond 0.27 mg cm(-2). We showed that the Multiplex(®) can be advantageously used in vineyards on intact clusters for the non-destructive assessment of anthocyanin content of vine blocks and can now be tested on other fruits and vegetables based on the same model.