Search results for "Ambrosia"
showing 10 items of 48 documents
Evidence for Succession and Putative Metabolic Roles of Fungi and Bacteria in the Farming Mutualism of the Ambrosia Beetle Xyleborus affinis.
2020
The bacterial and fungal community involved in ambrosia beetle fungiculture remains poorly studied compared to the famous fungus-farming ants and termites. Here we studied microbial community dynamics of laboratory nests, adults, and brood during the life cycle of the sugarcane shot hole borer, Xyleborus affinis. We identified a total of 40 fungal and 428 bacterial operational taxonomic units (OTUs), from which only five fungi (a Raffaelea fungus and four ascomycete yeasts) and four bacterial genera (Stenotrophomonas, Enterobacter, Burkholderia, and Ochrobactrum) can be considered the core community playing the most relevant symbiotic role. Both the fungal and bacterial populations varied s…
Impact of Rearing Conditions on the Ambrosia Beetle’s Microbiome
2018
Ambrosia beetles, along with termites and leafcutter ants, are the only fungus-farming lineages within the tree of life. Bacteria harbored by ambrosia beetles may play an essential role in the nutritional symbiotic interactions with their associated fungi
Variability and cryptic heteromorphism of Ambrosia artemisiifolia seeds: What consequences for its invasion in France
2007
International audience; Background and Aims:Ambrosia artemisiifolia is a ruderal weed introduced from North America to Europe. It produces large amount of achenes which are highly heterogeneous in size. Due to the preponderant role of propagules in invasive plant processes, the achene mass variability related to germination, dispersal strategy and life history traits of offspring were investigated within this species. Methods:The variability in achene mass was quantified among six populations sampled in different habitats. The effects of achene mass variation on germination were studied. The percentages of floating and non-floating achenes were evaluated in the studied populations. The cons…
Can the large ecological amplitude of Ambrosia artemisiifolia explain its invasive success in France?
2008
International audience; In order to understand the successful spread of Ambrosia artemisiifolia in France, the variability of colonised habitat by this species was studied at 48 locations, from its central to peripheral area of distribution. Each site was characterised by a vegetation survey, a description of the A. artemisiifolia population and a soil analysis. Differences in the number of species, Shannon diversity index, evenness index and plant life form spectra were compared among the sites. A total of 276 species occurring along with A. artemisiifolia was observed. Therophytes and hemicryptophytes represented more than 80% of all the species. The two most frequent species occurring al…
Gene flow and population admixture as the primary post-invasion processes in common ragweed (Ambrosia artemisiifolia) populations in France
2010
*An improved inference of the evolutionary history of invasive species may be achieved by analyzing the genetic variation and population differentiation of recently established populations and their ancestral (historical) populations. Employing this approach, we investigated the role of gene flow in the post-invasion evolution of common ragweed (Ambrosia artemisiifolia). *Using eight microsatellite loci, we compared genetic diversity and structure among nine pairs of historical and recent populations in France. Historical populations were reconstructed from herbarium specimens dated from the late 19th to early 20th century, whereas recent populations were collected within the last 5 yr. *Re…
Seed bank dynamics of an invasive plant, Ambrosia artemisiifolia L.
2008
AbstractThe seed-bank dynamics ofAmbrosia artemisiifolia(Asteraceae), an annual invasive plant introduced from North America to Europe, were studied in nine French populations developing in field crops, set-asides or wastelands. The vertical distribution of seeds was studied in two different depth sections (0–5 cm and 5–20 cm), and the spatial horizontal pattern of distribution was analysed for two selected field-crop and set-aside populations. The proportions of dormant, non-dormant and dead seeds, as well as the changes in seed-bank dormancy over time, were evaluated. Natural seedling recruitment and its variation under different disturbance treatments in competitive set-asides were also …
Côté mauvaises herbes, tir de barrage sur trois envahissantes
2006
National audience; Les plantes envahissantes sont évoquées à la conférence sur les zones non agricoles de l'AFPPà Avignon les 11 et 12octobre 2006. La situation à leur égard en France et en Europe est présentée, notamment les dispositions réglementaires et l'identité des 34 principales espèces. Deux communications traitent de l'ambroisie à feuille d'armoise Ambrosia artemisiifolia. Un point sur les méthodes de lutte mécanique, chimique, etc.) insiste sur l'intérêt de la prévention (enherbement, etc.)et de la concertation entre acteurs agricoles et non agricoles. Des essais de lutte chimique (glyphosate ou glufosinate-ammonium en 2004 et 2005, les montrent équivalents et intéressants en débu…
Les paradoxes du glufosinate et glyphosate. Comportement dans l'ambroisie à feuilles d'armoise
2006
BEHAVIOUR OF GLUFOSINATE ANDGLYPHOSATE IN COMMONRAGWEED:APPARENT PARADOXAND SURPRISES We examined the foliar epidermis of commonragweed (Ambrosia artemisiifolia L.) plants and studied the behaviour of the herbicides glufosinate and glyphosate in this species. Both leaf surfaces exhibited 3 types of trichomes, according to their size and shape. Epicuticular waxes appeared amorphous, which may explain high levels of spray retention. Glufosinate and glyphosate were rapidly and almost completely taken up by common ragweed leaves; half maximum uptake was nearly reached after 5 and 3 h, respectively. The longest trichomes were stained with AgN03, indicating the presence of hydrophilic domains, wh…
Multi-model ensemble simulations of olive pollen distribution in Europe in 2014: current status and outlook
2017
"Çalışmada 29 yazar bulunmaktadır. Bu yazarlardan sadece Bursa Uludağ Üniversitesi mensuplarının girişleri yapılmıştır” The paper presents the first modelling experiment of the European-scale olive pollen dispersion, analyses the quality of the predictions, and outlines the research needs. A 6-model strong ensemble of Copernicus Atmospheric Monitoring Service (CAMS) was run throughout the olive season of 2014, computing the olive pollen distribution. The simulations have been compared with observations in eight countries, which are members of the European Aeroallergen Network (EAN). Analysis was performed for individual models, the ensemble mean and median, and for a dynamically optimised c…
Demande d’avis relatif à la réalisation d’une analyse de risques relative à l’ambroisie trifide (Ambrosia trifida L.) et pour l’élaboration de recomm…
2017
Le 22 octobre 2014, le Parlement européen et le Conseil ont publié un règlement relatif à la prévention et à la gestion de l'introduction et de la propagation des espèces exotiques envahissantes (EEE). Ce règlement prévoit, en particulier àson article 19, que les États membres mettent en place des mesures efficaces de gestion vis-à-vis d'une liste d'EEE dites préoccupantes pour l'Union Européenne (UE) qui, selon l'article 4, doit être adoptée, par voie d'actes d'exécution, par la Commission européenne début 2016. Cette liste sera régulièrement révisée. Ainsi l'inscription d'une espèce dans cette liste se traduira par la mise en place d'actions de prévention et de lutte coordonnées entre les…