Effets du N minéral et du génotype de la plante sur la croissance et la nodulation de Faidherbia albida

2002 ◽  
Vol 80 (3) ◽  
pp. 241-254 ◽  
Author(s):  
Mahamadi Dianda ◽  
François-P. Chalifour
Keyword(s):  
Faidherbia Albida ◽  
Mineral N ◽  
Western Africa ◽  
Bradyrhizobium Strain ◽  
Aerial Parts ◽  
Highly Sensitive ◽  
Seed Origin ◽  
C And N ◽  
Growth Differences ◽  
Selection Of

Sahelian soils are recognized for their low N content, but their mineral N concentrations can often be high enough to inhibit N2 fixation in cultivated legumes. However, the quest for symbiotic plant genotypes tolerant of mineral N is poorly documented for nitrogen-fixing trees. The behaviour of N2 fixing symbioses with regard to nitrogen fertilization was observed in different Faidherbia albida (Del) A. Chev. genotypes. Twelve distinct lineages of the species, obtained from four regions of western Africa, were cultivated for 75 days in the presence of 0–6 mol·m–3 N provided as NH4NO3. Plants were separately inoculated with two Bradyrhizobium strains, and cultivated on sandy soil in a nursery. Aerial and root parts lengths and masses, collar diameters, and ratios of height to length (H/P) of taproot, and aerial to root (MA/MR) parts masses increased with increased N level. Plants showed significant growth differences linked with seed origin, and with lineage for a same origin. Genotypical variations were observed for concentrations as well as C and N total uptakes, C/N ratio measured in aerial parts, and N2 fixation. Nodule number and mass were greatly reduced in the presence of 2 mol·m–3 N. The extent of this reduction was dependent, to a lesser degree, on seed origin and Bradyrhizobium strain. Data show that F. albida – Bradyrhizobium symbiosis is highly sensitive to mineral N. It is suggested that selection of symbiotic partners for tolerance to mineral N might greatly improve the agronomic behaviour of F. albida.Key words: Faidherbia albida, lineages, Bradyrhizobium, symbiosis, nodulation, growth, ammonium nitrate.

Selection of an aptamer against Muscovy duck parvovirus for highly sensitive rapid visual detection by label-free aptasensor

Talanta ◽  
2018 ◽  
Vol 176 ◽  
pp. 214-220 ◽  
Author(s):  
Taofeng Lu ◽  
Qin Ma ◽  
Wenzhuo Yan ◽  
Yuanzhi Wang ◽  
Yuanyuan Zhang ◽  
...  
Keyword(s):  
Visual Detection ◽  
Muscovy Duck ◽  
Label Free ◽  
Highly Sensitive ◽  
Muscovy Duck Parvovirus ◽  
Selection Of

Selection of a DNA Aptamer against Zearalenone and Docking Analysis for Highly Sensitive Rapid Visual Detection with Label-Free Aptasensor

2018 ◽  
Vol 66 (45) ◽  
pp. 12102-12110 ◽  
Author(s):  
Yuanyuan Zhang ◽  
Taofeng Lu ◽  
Yue Wang ◽  
Chenxi Diao ◽  
Yan Zhou ◽  
...  
Keyword(s):  
Visual Detection ◽  
Dna Aptamer ◽  
Label Free ◽  
Docking Analysis ◽  
Highly Sensitive ◽  
Selection Of

scholarly journals A comparison of nitrogen and carbon reserves in acid sulphate and non acid sulphate soils in western Finland

2008 ◽  
Vol 14 (1) ◽  
pp. 57 ◽  
Author(s):  
M. PAASONEN-KIVEKÄS ◽  
M. YLI-HALLA
Keyword(s):  
Groundwater Level ◽  
Agricultural Practices ◽  
Density Field ◽  
Mineral N ◽  
Total N ◽  
N Retention ◽  
Acid Sulphate ◽  
Agricultural Catchments ◽  
Acid Sulphate Soils ◽  
C And N

Previous studies suggest that nitrogen (N) loads from acid sulphate soil (AS soil) catchments in Finland are higher than those from other agricultural catchments. This study seeks to explain this difference by measuring carbon (C) and N profiles in both an AS soil and a neighbouring non AS soil. In Lapua, western Finland, two adjacent fields (Dystric Cambisols), subjected to similar agricultural practices, were analysed to the depth of 240 cm for pH, total C (Ctot), total N (Ntot), NH4 +-N, NO3 --N, sulphur and bulk density. Field A, an AS soil, contained sulfidic materials and 0.9% Ctot below 170 cm, while Field B, not an AS soil, had 0.3% Ctot in the subsoil and no sulfides. In these soils, the groundwater level declined below 200 cm in summer, subjecting the subsoil to oxidation. This study revealed large stocks of Ctot, Ntot, and mineral N in the subsoil, particularly in the AS soil. At 20–240 cm, Field A contained 292 tons of Ctot ha-1 and 25 tons of Ntot ha-1, while Field B had 152 tons of Ctot ha-1 and 11 tons of Ntot ha-1. Field A contained up to 435 kg of mineral N ha-1 in autumn, while in Field B there was only up to 137 kg of mineral N ha-1. In Field A, NH4 +-N dominated strongly, while NO3 --N dominated in Field B. It is suggested that the greater concentration of mineral N in the AS soil is due to 1) a greater stock of total (mineralizable) N and 2) the slower rate of nitrification resulting in substantial NH4 +-N retention on cation exchange sites.;

Selection of DNA aptamers and establishment of an effective aptasensor for highly sensitive detection of cefquinome residues in milk

The Analyst ◽  
2018 ◽  
Vol 143 (13) ◽  
pp. 3202-3208 ◽  
Author(s):  
Lihui Wang ◽  
Chuchu Wang ◽  
Hao Li
Keyword(s):  
Respiratory Infection ◽  
Bovine Mastitis ◽  
Generation Cephalosporin ◽  
Sensitive Detection ◽  
Fourth Generation ◽  
Dna Aptamers ◽  
Highly Sensitive ◽  
Highly Sensitive Detection ◽  
Selection Of

Cefquinome (CFQ), which is a fourth-generation cephalosporin approved for veterinary use only, has been widely used for treating porcine or bovine respiratory infection, bovine mastitis and other diseases.

scholarly journals Maize root and shoot litter quality controls short-term CO<sub>2</sub> and N<sub>2</sub>O emissions and bacterial community structure of arable soil

2020 ◽  
Vol 17 (4) ◽  
pp. 1181-1198 ◽  
Author(s):  
Pauline Sophie Rummel ◽  
Birgit Pfeiffer ◽  
Johanna Pausch ◽  
Reinhard Well ◽  
Dominik Schneider ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Bacterial Community Structure ◽  
Litter Quality ◽  
Maize Root ◽  
N2o Emissions ◽  
Soil Mineral N ◽  
Soil Mineral ◽  
Mineral N ◽  
Root Litter ◽  
C And N

Abstract. Chemical composition of root and shoot litter controls decomposition and, subsequently, C availability for biological nitrogen transformation processes in soils. While aboveground plant residues have been proven to increase N2O emissions, studies on root litter effects are scarce. This study aimed (1) to evaluate how fresh maize root litter affects N2O emissions compared to fresh maize shoot litter, (2) to assess whether N2O emissions are related to the interaction of C and N mineralization from soil and litter, and (3) to analyze changes in soil microbial community structures related to litter input and N2O emissions. To obtain root and shoot litter, maize plants (Zea mays L.) were cultivated with two N fertilizer levels in a greenhouse and harvested. A two-factorial 22 d laboratory incubation experiment was set up with soil from both N levels (N1, N2) and three litter addition treatments (control, root, root + shoot). We measured CO2 and N2O fluxes, analyzed soil mineral N and water-extractable organic C (WEOC) concentrations, and determined quality parameters of maize litter. Bacterial community structures were analyzed using 16S rRNA gene sequencing. Maize litter quality controlled NO3- and WEOC availability and decomposition-related CO2 emissions. Emissions induced by maize root litter remained low, while high bioavailability of maize shoot litter strongly increased CO2 and N2O emissions when both root and shoot litter were added. We identified a strong positive correlation between cumulative CO2 and N2O emissions, supporting our hypothesis that litter quality affects denitrification by creating plant-litter-associated anaerobic microsites. The interdependency of C and N availability was validated by analyses of regression. Moreover, there was a strong positive interaction between soil NO3- and WEOC concentration resulting in much higher N2O emissions, when both NO3- and WEOC were available. A significant correlation was observed between total CO2 and N2O emissions, the soil bacterial community composition, and the litter level, showing a clear separation of root + shoot samples of all remaining samples. Bacterial diversity decreased with higher N level and higher input of easily available C. Altogether, changes in bacterial community structure reflected degradability of maize litter with easily degradable C from maize shoot litter favoring fast-growing C-cycling and N-reducing bacteria of the phyla Actinobacteria, Chloroflexi, Firmicutes, and Proteobacteria. In conclusion, litter quality is a major driver of N2O and CO2 emissions from crop residues, especially when soil mineral N is limited.

Dwarf Galaxies and Cluster Environments

2018 ◽  
Vol 14 (S344) ◽  
pp. 373-376
Author(s):  
Yasuhiro Hashimoto ◽  
J. Patrick Henry ◽  
Hans Böhringer
Keyword(s):  
Dwarf Galaxies ◽  
Dwarf Galaxy ◽  
Detection Algorithm ◽  
Diffuse Light ◽  
X Ray ◽  
Optical Images ◽  
Highly Sensitive ◽  
The Galaxy ◽  
Galaxy Populations ◽  
Selection Of

AbstractWe report an investigation of the properties of dwarf galaxies (Mr < -15) inside 26 clusters at z = 0.15 – 0.25, using the X-ray data from the Chandra archive, and optical images taken with Subaru Suprime-Cam. Our results include: 1. Investigation of the dwarf galaxy density distribution is sensitive to the background galaxies and the choice of colour selection of galaxies. 2. Cluster-centric dwarf-to-giant ratio is highly sensitive to the level of subtracted background galaxies. 3. A certain fraction of faint galaxies always remain undetected by the detection algorithm near the center of clusters, even after carefully treating the halo or extra diffuse light created by bright galaxies. The number of ‘undetected’ faint galaxies varies significantly from cluster to cluster, and even from pointing to pointing. 4. Dwarf galaxies extend up to 2 Mpc from the center in most clusters. Meanwhile, the distribution of blue dwarf galaxies extends more to the outside. 5. For a given colour, the spatial distributions of dwarf galaxies and giant galaxies become similar. Namely, the most of the radial distribution comes from the colour, rather than the size, of galaxies. 6. Relative to the NFW profile, all of the galaxy populations are showing a deficit near the cluster core (r < 0.3 Mpc). 7. The dwarf-to-giant ratio shows no variation against cluster measures such as the richness and X-ray luminosity, as well as various cluster X-ray characteristics related to possible dynamical status of clusters.

scholarly journals Method for Sorting and Pairwise Selection of Nanobodies for the Development of Highly Sensitive Sandwich Immunoassays

2015 ◽  
Vol 87 (23) ◽  
pp. 11907-11914 ◽  
Author(s):  
Martín A. Rossotti ◽  
Macarena Pirez ◽  
Andres Gonzalez-Techera ◽  
Yongliang Cui ◽  
Candace S. Bever ◽  
...  
Keyword(s):  
Highly Sensitive ◽  
Selection Of

scholarly journals Mineralization of pig slurry compost treated with retorted oil shale and dicyandiamide in two contrasting soils

2021 ◽  
Vol 56 ◽  
Author(s):  
Luanna Corrêa Monteiro ◽  
Celso Aita ◽  
Janquieli Schirmann ◽  
Stefen Barbosa Pujo ◽  
Diego Antônio Giacomini ◽  
...  
Keyword(s):  
Oil Shale ◽  
Clay Soil ◽  
Sandy Loam ◽  
Sandy Loam Soil ◽  
N Immobilization ◽  
Pig Slurry ◽  
Mineral N ◽  
Total N ◽  
Loam Soil ◽  
C And N

Abstract: The objective of this work was to evaluate carbon and nitrogen mineralization in the soil after the application of composts produced in an automated composting plant, using pig slurry (PS) with and without the addition of retorted oil shale (ROS) and dicyandiamide (DCD) during composting. Laboratory studies were carried out for 180 days on two soils with contrasting characteristics: sandy-loam Typic Paludalf and clay Rhodic Hapludox, which were managed for more than 10 years under a no-tillage system. The composts were thoroughly mixed with the soils. The mineralization of the C and N from the compost was evaluated by measuring continuously CO2 emissions and periodically mineral N (NH4+ + NO3-) content in the soils, respectively. The mineralization of the C from the compost without ROS and DCD was higher in the sandy-loam soil (20.5%) than in the clay soil (13.9%). Similarly, 19.4% of the total N from the compost was mineralized in the sandy-loam soil and 10.9% in the clay soil. The presence of ROS in the compost reduced C mineralization by 54%, compared with the treatment without additives, in the sandy-loam soil and caused net N immobilization in both soils during incubation. The addition of DCD during PS composting did not affect the mineralization of the C and N from the compost in both soils. The addition of ROS during the composting of PS favors the retention of the C from the compost in the soil, especially in the sandy-loam one, but results in a net N immobilization.

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