Search results for "Spacer"
showing 10 items of 247 documents
BythinellaMoquin-Tandon, 1856 (Gastropoda: Rissooidea: Bythinellidae) in Romania: species richness in a glacial refugium
2009
Mitochondrial cytochrome oxidase I (COI) and ribosomal internal transcribed spacer 1 (ITS-1) sequences were analysed in 12 Romanian Bythinella populations. Phylogenetic relationships were inferred using maximum parsimony, maximum likelihood and Bayesian techniques. For COI, the Kimura two-parameter (K2P) distances and haplotype networks were computed. Two sympatric and four allopatric groups were distinguished. The K2P distances are similar to those for congeneric rissooids, so each of the six groups represents a species. Two are identified as Bythinella molcsanyi H. Wagner, 1941, and Bythinella dacica Grossu, 1946. The other four groups cannot be ascribed to any known Bythinella. The occur…
ITS region of the rDNA of Pythium rhizosaccharum sp. nov. isolated from sugarcane roots: taxonomy and comparison with related species.
2003
Pythium rhizosaccharum (F-1244) was isolated from soil samples taken in the rhizosphere of sugarcane (Saccharum officinarum) in the north-eastern India. This species is characterized by its smooth-walled, spherical sporangia and rarely formed sexual structures. When formed, the antheridial branches wrap around the oogonia and soon disappear after fertilization. The internal transcribed spacer (ITS) region of its rDNA is comprised of 904 bases. The taxonomical description of this new species and its comparison with related species are given here, together with the nucleotide sequences of the ITS1 and ITS2, and the 5.8S gene of its ribosomal nuclear DNA.
Impact of wheat straw decomposition on successional patterns of soil microbial community structure
2009
International audience; The dynamics of indigenous bacterial and fungal soil communities were followed throughout the decomposition of wheat straw residue. More precisely, such dynamics were investigated in the different soil zones under the influence of decomposing wheat straw residue (i.e. residues, soil adjacent to residue = detritusphere, and bulk soil). The genetic structures of bacterial and fungal communities were compared throughout the decomposition process long by applying B- and F-ARISA (for bacterial and fungal-automated ribosomal intergenic spacer analysis) to DNA extracts from these different zones. Residue decomposition induced significant changes in bacterial and fungal comm…
Impact of inoculation with the phytostimulatory PGPR Azospirillum lipoferum CRT1 on the genetic structure of the rhizobacterial community of field-gr…
2009
International audience; The phytostimulatory PGPR Azospirillum lipoferum CRT1 was inoculated to maize seeds and the impact on the genetic structure of the rhizobacterial community in the field was determined during maize growth by Automated Ribosomal Intergenic Spacer Analysis (ARISA) of rhizosphere DNA extracts. ARISA fingerprints could differ from one plant to the next as well as from one sampling to the next. Inoculation with strain CRT1 enhanced plant-to-plant variability of the ARISA fingerprints and caused a statistically significant shift in the composition of the indigenous rhizobacterial community at the first two samplings. This is the first study on the ecological impact of Azosp…
Vigna mungo, V. radiata and V. unguiculata plants sampled in different agronomical-ecological-climatic regions of India are nodulated by Bradyrhizobi…
2009
International audience; Vigna mungo, Vigna radiata and Vigna unguiculata are important legume crops cultivated in India, but little is known about the genetic resources in native rhizobia that nodulate these species. To identify these bacteria, a core collection of 76 slow-growing isolates was built from root nodules of V. mungo, V. radiata and V. unguiculata plants grown at different sites within three agro-ecological-climatic regions of India. The genetic diversity of the bacterial collection was assessed by restriction fragment length polymorphism (RFLP) analysis of PCR-amplified DNA fragments of the 16S–23S rDNA intergenic spacer (IGS) region, and the symbiotic genes nifH and nodC. One …
Plant phenology and genetic variability in root and nodule development strongly influence genetic structuring of Rhizobium leguminosarum biovar vicia…
2008
Publication Inra prise en compte dans l'analyse bibliométrique des publications scientifiques mondiales sur les Fruits, les Légumes et la Pomme de terre. Période 2000-2012. http://prodinra.inra.fr/record/256699; International audience; The symbiotic relationships between legumes and their nitrogen (N-2)-fixing bacterial partners (rhizobia) vary in effectiveness to promote plant growth according to both bacterial and legume genotype. To assess the selective effect of host plant on its microsymbionts, the influence of the pea (Pisum sativum) genotype on the relative nodulation success of Rhizobium leguminosarum biovar viciae (Rlv) genotypes from the soil populations during plant development h…
CFD simulations of spacer-filled channels for pressure retarded osmosis applications
2015
Different spacer features and operating conditions were investigated in order to identify a good compromise between concentration polarization and pumping power reductions.
Fungal Assemblages Associated with Roots of Halophytic and Non-halophytic Plant Species Vary Differentially Along a Salinity Gradient
2012
Structure of fungal communities is known to be influenced by host plants and environmental conditions. However, in most cases, the dynamics of these variation patterns are poorly understood. In this work, we compared richness, diversity, and composition between assemblages of endophytic and rhizospheric fungi associated to roots of two plants with different lifestyles: the halophyte Inula crithmoides and the non-halophyte I. viscosa (syn. Dittrichia viscosa L.), along a spatially short salinity gradient. Roots and rhizospheric soil from these plants were collected at three points between a salt marsh and a sand dune, and fungi were isolated and characterized by ITS rDNA sequencing. Isolates…
Lulwoana sp., a dark septate endophyte (DSE) in roots of Posidonia oceanica (L.) Delile seagrass
2014
Posidonia oceanica is the most common, widespread and important monocotyledon seagrass in the Mediterranean Basin, and hosts a large biodiversity of species, including microorganisms with key roles in the marine environment. In this study, we ascertain the presence of a fungal endophyte in the roots of P. oceanica growing on different substrata (rock, sand and matte) in two Sicilian marine meadows. Staining techniques on root fragments and sections, in combination with microscope observations, were used to visualise the fungal presence and determine the percentage of fungal colonisation (FC) in this tissue. In root fragments, statistical analysis of the FC showed a higher mean in roots anch…
Sequence analysis of the rDNA spacer of Paracentrotus lividus and observations about pre-rRNA processing. NTS sequence of Paracentrotus lividus rDNA.
1993
We have isolated and sequenced one intergenic region and a small part of the flanking regions (18S and 26S rRNA coding regions) of the rRNA-encoding genes (rDNA) from the sea urchin Paracentrotus lividus. This region is about 3.8 Kb long. Northern blot hybridizations and S1 mapping experiments demonstrated the presence of a partially processed 21S rRNA precursor while has the same 5' terminus as the 32S primary precursor, also in developmental stages characterized by a low rate of rRNA synthesis.