Search results for "Geta"
showing 10 items of 3789 documents
Protocol for the Definition of a Multi-Spectral Sensor for Specific Foliar Disease Detection: Case of “Flavescence Dorée”
2018
Flavescence Doree (FD) is a contagious and incurable grapevine disease that can be perceived on leaves. In order to contain its spread, the regulations obligate winegrowers to control each plant and to remove the suspected ones. Nevertheless, this monitoring is performed during the harvest and mobilizes many people during a strategic period for viticulture. To solve this problem, we aim to develop a Multi-Spectral (MS) imaging device ensuring an automated grapevine disease detection solution. If embedded on a UAV, the tool can provide disease outbreaks locations in a geographical information system allowing localized and direct treatment of infected vines. The high-resolution MS camera aims…
An ecological multi-Level theory of competition for resources used to analyse density-dependence effects in fruit production
2014
International audience; Lescourret and Génard (2003) developed a multi-level theory of competition for resources applied to fruit production, considering that any collection of unit parts (cells or seeds in a fruit, fruits in an infructescence or in a tree...) can form a population and the population is subject to competition, whatever the level of organization. The principles of the theory are that the mass of each unit decreases when the number of units in the population increases and that the total mass of the population increases as the number of units increases until it reaches a maximum, after which it decreases. A three-parameter model based on that theory was used to analyse the lev…
Sex-ratio and male sexual characters in a population of Blue tits Parus caeruleus
2005
Sex allocation theory proposes that parents should bias the sex ratio of their offspring if the reproductive value of one sex is greater than that of the other. In the monogamous blue tit (Parus caeruleus), males have a greater variance in reproductive success than females, and high-quality males have higher reproductive success than high-quality females due to extrapair paternity. Consequently, females mating with attractive males are expected to produce broods biased toward sons, as sons benefit more than daughters from inheriting their father’s characteristics. Song and plumage color in birds are secondary sexual characters indicating male quality and involved in female choice. We used t…
Fruit size in relation to competition for resources: A common model shared by two species and several genotypes grown under contrasted carbohydrate l…
2012
International audience; Fruit size is one important criterion of fruit external quality affecting consumer acceptance. The effects of seed number on fruit size in two fleshy fruits, grape and tomato, of different genotypes and grown under distinct carbohydrate availability levels were analyzed with a model. The two-parameter model described within-fruit resource competition and was able to well represent the commonly observed decrease in fresh weight per seed along with the increase in number of seeds, regardless of species, genotypes, and carbohydrate levels that were evaluated in this study. However, carbohydrate levels largely modified the correlation between seed number and fresh weight…
Pseudomonas salomonii sp. nov., pathogenic on garlic, and Pseudomonas palleroniara sp. nov., isolated from rice
2002
International audience; A total of 26 strains, including 15 strains isolated from garlic plants with the typical symptoms of 'Café au lait' disease and 11 strains isolated from diseased or healthy rice seeds and sheaths infested by Pseudomonas fuscovaginae, were compared with 70 type or reference strains of oxidase-positive pathogenic or non-pathogenic fluorescent pseudomonads. The strains were characterized by using a polyphasic taxonomic approach. Numerical taxonomy of phenotypic characteristics showed that the garlic and rice strains were related to each other. However, they clustered into separate phenons, distinct from those of the other strains tested, and were different in several nu…
Soil suppressiveness to plant diseases
2007
Prod 2018-286 SPE BIOmE IPM INRA; International audience
Free Radicals Mediate Systemic Acquired Resistance
2014
Summary: Systemic acquired resistance (SAR) is a form of resistance that protects plants against a broad spectrum of secondary infections. However, exploiting SAR for the protection of agriculturally important plants warrants a thorough investigation of the mutual interrelationships among the various signals that mediate SAR. Here, we show that nitric oxide (NO) and reactive oxygen species (ROS) serve as inducers of SAR in a concentration-dependent manner. Thus, genetic mutations that either inhibit NO/ROS production or increase NO accumulation (e.g., a mutation in S-nitrosoglutathione reductase [GSNOR]) abrogate SAR. Different ROS function additively to generate the fatty-acid-derived azel…
Effects of resveratrol on the ultrastructure of Botrytis cinerea conidia and biological significance in plant/pathogen interactions
2012
International audience; Many roles have been ascribed to stilbenes, namely as antimicrobial, deterrent or repellent compounds in plants, protecting them from attacks by fungi, bacteria, nematodes or herbivores, acting both as constitutive and active defense (phytoalexin) compounds. More recently, stilbenes (especially resveratrol and its derivatives) were acclaimed for their wondrous effects and wide range of purported healing and preventive powers as cardioprotective, antitumor, neuroprotective and antioxidant agents. Although there is a huge number of works concerning the role of resveratrol in human health, reports on the antifungal activity of this compound are still scarce. This study …
The Sulfated Laminarin Triggers a Stress Transcriptome before Priming the SA- and ROS-Dependent Defenses during Grapevine’s Induced Resistance agains…
2014
Grapevine (Vitis vinifera) is susceptible to many pathogens which cause significant losses to viticulture worldwide. Chemical control is available, but agro-ecological concerns have raised interest in alternative methods, especially in triggering plant immunity by elicitor treatments. The b-glucan laminarin (Lam) and its sulfated derivative (PS3) have been previously demonstrated to induce resistance in grapevine against downy mildew (Plasmopara viticola). However, if Lam elicits classical grapevine defenses such as oxidative burst, pathogenesis-related (PR)-proteins and phytoalexin production, PS3 triggered grapevine resistance via a poorly understood priming phenomenon. The aim of this st…
Mycotoxins in maize: mitigation actions, with a chain management approach
2020
Maize is the principal staple food/feed crop exposed to mycotoxins, and the co-occurrence of multiple mycotoxins and their metabolites has been well documented. This review presents the infection cycle, ecology, and plant-pathogen interactions of Aspergillus and Fusarium species in maize, and current knowledge on maize chain management to mitigate the occurrence of aflatoxins and fumonisins. Preventive actions include at pre-harvest, as part of cropping systems, at harvest, and at postharvest, through storage, processing, and detoxification to minimize consumer exposure. Preventive actions in the field have been recognized as efficient for reducing the entrance of mycotoxins into production…