Search results for "010606 plant biology & botany"
showing 10 items of 1457 documents
Regulation of endocytosis by external stimuli in plant cells
2009
International audience; Endocytosis is an essential process for the normal growth and development of eukaryotic cells. This mini-review presents an overview of endocytosis regulation in challenging environmental conditions such as nutrient availability, hormonal treatment or abiotic/biotic stress in plant cells. Recent data establishing a relationship between endocytosis and reactive oxygen species (ROS) production are also discussed.
Characterization of Fusarium oxysporum populations by growth parameter evaluation in microtiter plates
1997
Trophic competition for the C source is the main mechanism involved in the interaction between pathogenic and non-pathogenic populations of Fusarium oxysporum. Therefore, a phenotypical characterization based on the growth characteristics of these populations will provide classical genotypical characterizations with additionnal information of ecological significance.
A multisite-cooperative research programme on risk assessment of transgenic crops
1999
Genetically modified plants are now being commercialised in several countries as regulatory authorities consider that the balance of risk versus benefit is beneficial. However, numerous questions remain unanswered, especially the impact of these plants when used over large areas and under a range of variable environmental conditions. Some issues need to be re-evaluated [1, 2]. Risk/safety analysis, as well as prospects of transgenic crops depend on the scale which is to be considered. Extrapolation of methods, and laboratory and greenhouse results, to large-scale farmers’ fields, may provide useful preliminary data, but is not a sound approach to the study of the consequences of the commerc…
Raspberry breeding and biotisation for increasing plant stress tolerance and antioxidant activity
2008
International audience; Chemical inputs used in red fruit production can be detrimental to the environment and pesticides are not always efficient in controlling plant diseases. In addition, it is suspected that conventional agricultural practices have a negative impact on antioxidant activities in red fruits. Therefore new cultural approaches are required in order to produce red fruits of high quality. This involves an integrated programme of plant breeding and development of sustainable agricultural practices. Antioxidant activity was compared in leaves and berries of six raspberry cultivars for the selection of varieties for a breeding programme. This showed that cultivars that had the h…
Influence of nitrogen availability on seed nitrogen accumulation in pea
1999
International audience; The final seed nitrogen concentration (the ratio of seed N and dry matter content) is highly variable in pea (Pisum sativum L.) and N remobilization during seed filling may limit yield by restricting the seed filling period. This study was conducted to determine how seed N accumulation is regulated in pea. The effect of N availability and distribution on individual seed N accumulation rate at different nodes was investigated in three genotypes grown in the field and glasshouse under various levels of N fertilizer, depodding, and defoliation. The N content of vegetative plants parts (stems, leaves, podwalls) and seeds from three mainstem nodes were regularly recorded.…
The mycorrhizal soil infectivity and arbuscular mycorrhizal fungal spore communities in soils of different aged fallows in Senegal
2001
This work was carried out to determine the influence of the duration of fallow and of physico-chemical components of soils on the distribution of endomycorrhizal fungal spores and the mycorrhizal soil infectivity. The mycorrhization of indigenous plants from the fallows was examined and it was concluded that, except for Cassia obtusifolia, fungal colonization was poorly developed. No correlation was established between spore populations and duration of fallow or between grazed and fenced areas. The relationships between abundance of mycorrhizal spores and the physico-chemical characteristics of the soils were markedly variable among species of mycorrhizal fungi. The results did not provide …
Unravelling the determinants of freezing tolerance in Medicago truncatula: a first step towards improving the response of crop legumes to freezing st…
2020
International audience; Freezing is a major environmental limitation that affects biomass and seed productivity in a large number of crop species including legumes. Medicago truncatula is a model molecular‐genetic system for legume biology. A strategy to decipher freezing tolerance after a cold acclimation period in M. truncatula was developed using a quantitative genetic approach. Three main quantitative trait loci (QTL) with additive effects for freezing damage were detected on chromosomes 1, 4, and 6 using a recombinant inbred line population derived from a cross between the freezing‐tolerant accession F83005‐5 and the freezing‐sensitive accession DZA045‐5. The QTL on chromosome 6, named…
Biochemical Quality of Crop Residues and Carbon and Nitrogen Mineralization Kinetics under Nonlimiting Nitrogen Conditions
2000
International audience; Statistical relationships were established between the fate of C and N from 47 types of crop residues and their biochemical characteristics during a soil incubation at 15°C. The incubations were carried out under nonlimiting N in order to differentiate the effects of biochemical characteristics of residues from those of soil N availability. Depending on the residue, the apparent mineralization of residue C after 168 d varied from 330 to 670 g kg−1 of added C. Mineralization kinetics were described using a two-compartment decomposition model that decomposes according to first-order kinetics. Amounts of C mineralized after 7 d and the decomposition rate coefficient of …
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…
Polymorphism for interspecific hybridisation within a population of wild radish (Raphanus raphanistrum) pollinated by oilseed rape (Brassica napus)
2001
The within-population polymorphism of wild radish (Raphanus raphanistrum) for interspecific hybridisation with two cultivars of oilseed rape (Brassica napus) was investigated by hand crossing experiments and fluorescence microscopy. Wide variability among plants was observed in the ability of oilseed rape pollen to germinate on the wild radish stigma; the frequency of pistils showing pollen tubes ranged from 0 to 1, depending on the female plant. The ratio of fertilised ovules to the total number of ovules in ovaries where pollen tubes arrived ranged from 0.02 to 0.51. Overall, the results provide evidence for the presence of different phenotypes. In 40% of the plants, pistils had no or ver…