Search results for "Vegetal Biology"

Une chrysomèle contre l'ambroisie, est-ce réaliste ?

2016

Context - Despite intensive management practices carried out by stakeholders, common ragweed control is presently not sufficient to limit the spread of this annual invasive plant. Ali classical methods (mowing, chemical weeding, etc.) are limited in terms of efficiency. ln order to achieve a better management in the different habitats occupied by the plant, it is necessary to design innovative methods that could increase contra efficiency. The recent accidental introduction of a ragweed natural enemy in ltalia raises the question of the use of biological control agents. Could the regulation by a new phytophagous insect be considered as an integrated way of management in order to reduce the …

Permineralized coniferophytes from the Autun Basin: specimens from two new localities of Renault zone 3

2015

International audience; Four zones yielding silicified plant remains have been recognized in the Autun Basin by Renault (1893-1896). Zones 2, 3 and 4, characterized by Autunian plants, correspond to the successive formations of Igornay and Muse (lower Autunian), and Surmoulin-Millery (upper Autunian). Their paleobotanical content, together with that preserved as adpressions in the same formations, document paleofloral changes on the western side of the Tethys within a time interval extending from the latest Ghzelian (uppermost Pennsylvanian) to the early Sakmarian (lower Permian) (Broutin et al. 1999). The analyses realized so far indicate a progressive replacement of wetland plants by taxa…

La lutte biologique contre l'ambroisie à feuille d'armoise illustrée par l'exemple d'Ophraella communa : quels intérêts et quelles limites

2016

Common ragweed (Ambrosia artemisiifolia) was introduced in France over 150 years ago and its spreading across France now seems inexorable. The specific biology of this summer annual creates new problems for the managers of the various habitats where the plant can be found. The reduced possibility, or even the impossibility, to use traditional control means in certain environment conditions brings managers to consider biological control as one of the few possible means for slowing down the spread, or even pushing back the distribution area, of this invasive and allergenic plant. With Ophraella communa as an example, a reflection is presented on the benefit-risk balance of the introduction of…

Impact of herbicide-resistant transgenic plants on weed management and environment

2012

Does landscape diversity influence species fitness in farmland plants ?

2015

In agriculture, landscape management research has proven extremely valuable for explaining species amount, such as how species capture and utilize changed landscape resources to maintain population size and community diversity. What is surprising is the apparent lack of comparable studies on the effects of landscape properties and management on species fitness. Here, we search for "pathological" situations where landscape effects on farmland plant amount mask significantly different effects on fitness. We examined the case of 83 weed species in 256 fields distributed across the UK national scale. Whether at the local scale of the neighborhood or the larger scale of 2 km, we find landscape e…

Diversité fonctionnelle au sein des communautés de plantes adventices : effet de la rotation et du type de culture

2012

During this internship I investigated the effects of habitats i.e. field margin or the core of the field, and of crop sequences weed taxonomic and functional diversity in arable fields. We selected 75 fields from a database of flora surveys that have been conducted since 2005 in the area of Fénay. In the 75 fieds, the flora was sampled four consecutive years. The indices of Shannon-Weaver, Simpson and Pielou and species richness were selected for taxonomic study, while Rao's quadratic entropy and the community weighted mean (CWM) of the traits in the community were used for the functional study. Four functional traits were selected for the analyses. Our results showed that all studied facto…

Baselines and French Forests

2022

International audience

Expression Patterns of Key Hormones Related to Pea (Pisum sativum L.) Embryo Physiological Maturity Shift in Response to Accelerated Growth Conditions

2019

Protocols have been proposed for rapid generation turnover of temperate legumes under conditions optimized for day-length, temperature, and light spectra. These conditions act to compress time to flowering and seed development across genotypes. In pea, we have previously demonstrated that embryos do not efficiently germinate without exogenous hormones until physiological maturity is reached at 18 days after pollination (DAP). Sugar metabolism and moisture content have been implicated in the modulation of embryo maturity. However, the role of hormones in regulating seed development is poorly described in legumes. To address this gap, we characterized hormonal profiles (IAA, chlorinated auxin…

The evolution of nitric oxide signalling diverges between the animal and the green lineages

2019

AbstractNitric oxide (NO) is a ubiquitous signalling molecule with widespread distribution in prokaryotes and eukaryotes where it is involved in countless physiological processes. While the mechanisms governing nitric oxide (NO) synthesis and signalling are well established in animals, the situation is less clear in the green lineage. Recent investigations have shown that NO synthase, the major enzymatic source for NO in animals, is absent in land plants but present in a limited number of algae. The first detailed analysis highlighted that these new NO synthases are functional but display specific structural features and probably original catalytic activities. Completing this picture, analy…

Broomrape weeds. Underground mechanisms of parasitism and associated strategies for their control: a review

2016

prod 2018-285d SPE GESTAD Agrosup INRA CT?; International audience; Broomrapes are plant-parasitic weeds which constitute one of the most difficult-to-control of all biotic constraints that affect crops in Mediterranean, central and eastern Europe, and Asia. Due to their physical and metabolic overlap with the crop, their underground parasitism, their achlorophyllous nature, and hardly destructible seed bank, broomrape weeds are usually not controlled by management strategies designed for non-parasitic weeds. Instead, broomrape are in a current state of intensification and spread due to lack of broomrape-specific control programs, unconscious introduction to new areas and may be decline of …