- Algiers - Algeria
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Said AMRANI
USTHB, Faculté Des Sciences Biologiques, Faculty Member
- I'm working within the network "Algerian Biodiversity Group" founded for the survey, analysis, promotion and conserva... moreI'm working within the network "Algerian Biodiversity Group" founded for the survey, analysis, promotion and conservation of all the components of Algerian biodiversity by publishing articles, checklists and maintaining a dedicated websiteedit
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Research Interests: Computer Science, Natural Products, Complementary and Alternative Medicine, Computational Statistics, Collaboration, and 15 morePlant Biology, Network Analysis, Social Media, Open Innovation, Networking, Digital Communication, Bioactive molecules, Phytomedicine, Collaborative Research, Clinical research, Bioactive Compounds and Phytochemicals in Foos, Hashtag, Bioactive Compounds, Natural Products Research, and Pharmacology and pharmaceutical sciences
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La présente étude porte sur la nature des rhizobia associés aux légumineuses du genre Hippocrepis qui compte une dizaine d’espèces en Algérie et pour laquelle très peu de travaux ont été jusqu’ici consacrés. Les résultats de nos... more
La présente étude porte sur la nature des rhizobia associés aux légumineuses du genre Hippocrepis qui compte une dizaine d’espèces en Algérie et pour laquelle très peu de travaux ont été jusqu’ici consacrés. Les résultats de nos investigations qui ont portés sur 26 plants représentant 8 espèces de ce genre et provenant de 17 localités du nord et du sud du pays révèlent que tous les plants étaient nodulés et fixateurs d’azote, ce qui indique que les 8 espèces identifiées sont capables d’établir une symbiose efficiente avec les rhizobia présents dans les sols qui les supportent. Le séquençage du gène de l’ARN 16S des 26 souches de rhizobia isolées et authentifiées par des tests de nodulation au laboratoire permet de les assigner à 16 espèces de rhizobia réparties sur 5 genres: Ensifer, Mesorhizobium, Bradyrhizobium, Rhizobium et Neorhizobium avec une prédominance des représentants des genres Ensifer et Mesorhizobium. Les résultats de cette étude qui est la première dédiée spécifiqueme...
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Since their introduction at the beginning of the 19th century, Casuarina species have become important components of the Algerian landscape, yet the numbers of species present in Algeria and their identity, distribution, and symbiotic... more
Since their introduction at the beginning of the 19th century, Casuarina species have become important components of the Algerian landscape, yet the numbers of species present in Algeria and their identity, distribution, and symbiotic status are still not well understood. A survey conducted on 2,304 trees in 96 Casuarina stands across Algeria indicates that they are represented exclusively by five species: Casuarina cristata Miq., C. cunninghamiana Miq., C. equisetifolia L., C. glauca Sieber ex Spreng. and C. junghuhniana Miq. Two species, C. cunninghamiana and C. glauca, were the most common – the former occurring more often in the relatively humid and temperate areas of the country while the latter is most frequent in the drier and warmer areas. Production of seedlings of C. cunninghamiana and C. glauca in 12 nurseries resulted in low rates of spontaneous mycorrhizal infection frequency and nodulation, suggesting that inoculation of seedlings with selected mycorrhizal fungi and/or...
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Literature-based associations between ground beetles (Coleoptera: Carabidae) and Fungi. Data are provided as an importable MySQL database, as well as .csv tables, both as separate tables and as one merged dataset.
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Abstract: Seaward, M. R. D., Khadhri, A. & Amrani, S. 2021. Checklist of the lichens and lichenicolous fungi of Tunisia. – Herzogia 34: 400 – 427. Although lichens have been the subject of renewed interest for many countries... more
Abstract: Seaward, M. R. D., Khadhri, A. & Amrani, S. 2021. Checklist of the lichens and lichenicolous fungi of Tunisia. – Herzogia 34: 400 – 427. Although lichens have been the subject of renewed interest for many countries worldwide, this has not been the case for Tunisia where much of the territory continues to be largely under-explored. In order to promote lichenological research in Tunisia, a checklist was published in 1996 together with an historical overview and a bibliography compiled from a wide range of published sources. As a result of more recent field and herbarium work, a revised checklist containing 644 taxa (628 lichens and 16 lichenicolous and allied fungi) is provided, of which 230 taxa are additional to the previous checklist; it also takes into account the large number of changes to the nomenclature in recent years.
Our study aimed to determine the effect on barley (Hordeum vulgare L.) of adding potassium polyacrylate to a sandy soil under normal watering condition and drought. We focused on morphological and physiological characteristics of barley... more
Our study aimed to determine the effect on barley (Hordeum vulgare L.) of adding potassium polyacrylate to a sandy soil under normal watering condition and drought. We focused on morphological and physiological characteristics of barley and its rhizosphere bacterial community structure using Illumina Miseq sequencing. It was found that under normal watering condition (70% of soil water holding capacity (WHC)), the soil water retention increased with the SAP addition to the soil. Barley plant height and weight, leaf relative water content and protein content decreased under drought (35% of soil WHC), the addition of SAP eliminated the negative effect of drought on plants, the proline content was reduced from 2.71 μg g−1 leave dry weight with stressed plants to 0.99 μg g−1 with only 0.2% of SAP. The barley rhizophere bacterial community was affected by drought. Changes in relative abundance were noticed at both phyla and OTU level. The SAP addition (0.8%) shifted the barley rhizophere...
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Structures and chemical compounds causing integumentary inhibition of Erythrina corallodendron seeds in Algeria. – Phyton (Horn, Austria) 60: 161–172, with 4 figures and 1 table.* Erythrina corallodendron belonging to the genus Erythrina... more
Structures and chemical compounds causing integumentary inhibition of Erythrina corallodendron seeds in Algeria. – Phyton (Horn, Austria) 60: 161–172, with 4 figures and 1 table.* Erythrina corallodendron belonging to the genus Erythrina and the family Fabaceae is a tree growing in tropical and sub-tropical regions. The tree is mainly grown as an ornamental plant because of its nice orange flowers but is also considered as a medicinal plant. The aim of this study was to determine the causes of the limited germination rate of seeds under natural conditions. Even under favorable conditions (humidity, optimum temperature), a very low percentage of germination can be observed. Considerably higher percentages of germination of 99.5 % and 85.7 % were obtained after decortication and mechanical scarification, respectively. Also, the duration until the seeds germinated was reduced to only one day by both treatments. The integumentary germination inhibition is related to its impermeability, ...
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Abstract: Amrani, S., Seaward, M. R. D., Sipman, H. J. M. & Feuerer, T. 2018. Lichenological exploration of Algeria II: checklist of lichenized, lichenicolous and allied fungi. – Herzogia 31: 817–892. Despite more than two centuries... more
Abstract: Amrani, S., Seaward, M. R. D., Sipman, H. J. M. & Feuerer, T. 2018. Lichenological exploration of Algeria II: checklist of lichenized, lichenicolous and allied fungi. – Herzogia 31: 817–892. Despite more than two centuries of almost uninterrupted studies of the Algerian lichen flora, its diversity, ecology and biogeography remain much under-explored. Following the publication of our historical overview of lichenological exploration of Algeria (1798–2013) and an annotated bibliography of 171 titles in 2015, it was thought necessary to provide a basis for future studies in the form of a checklist of Algerian lichens and lichenicolous fungi. In all, 1051 lichen taxa and 43 species of lichenicolous and allied fungi are listed, and their synonyms used in publications on Algerian lichens are provided. An attempt has also been made to provide basic biogeographical data.
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Abstract The electrochemical oxidation of the neonicotinoid pesticide thiamethoxam (TMX) on a boron-doped diamond (BDD) anode was investigated. The effect of several operating parameters such as supporting electrolyte (0.025-0.1 M Na2SO4,... more
Abstract The electrochemical oxidation of the neonicotinoid pesticide thiamethoxam (TMX) on a boron-doped diamond (BDD) anode was investigated. The effect of several operating parameters such as supporting electrolyte (0.025-0.1 M Na2SO4, 0.1 M NaCl), current density (4–40 mA cm−2), TMX concentration (1–10 mg L−1 of active ingredient in a commercial formulation) and initial solution pH (3–11) on degradation was evaluated. The apparent rate constant of a pseudo-first order kinetic model was found to increase with increasing (i) current density (from 0.036 to 1 min−1 at 4 and 40 mA cm−2, 2 mg L−1 TMX and 0.1 M Na2SO4) and (ii) Na2SO4 concentration (from 0.037 to 0.25 min−1 at 0.025 and 0.1 M Na2SO4, 2 mg L−1 TMX and 16 mA cm−2 current density) and decreasing (iii) TMX concentration (from 0.05 to 0.73 min−1 at 10 and 1 mg L−1 TMX, 0.1 M Na2SO4 and 16 mA cm−2 current density) and (iv) initial solution pH (from 0.017 to 2.13 at pH 11 and 3, 0.1 M Na2SO4, 2 mg L−1 TMX and 16 mA cm−2 current density). Experiments in actual matrices, such as secondary treated wastewater and bottled water, resulted in lower kinetics (0.02 and 0.04 min−1, respectively) than in pure water (0.22 min−1), signifying competitive interactions between TMX and the matrix constituents. Of the latter, organic matter (1–15 mg L−1 in the form of humic acid), bicarbonates (>100 mg L−1) and chlorides (>100 mg L−1) all had a detrimental effect on degradation. The rate constant of TMX degradation in pure water was reduced by 82%, 71% and 36% in the presence of 15 mg L−1 humic acid or 500 mg L−1 bicarbonates or 500 mg L−1 chlorides, respectively. Fast TMX degradation (i.e. complete removal of 2 mg L−1 TMX in 20 min at 16 mA cm−2, 0.1 M Na2SO4, in pure water) is accompanied by slower mineralization (i.e. 91% total organic carbon removal at 120 min), indicating the formation of more resistant transformation by-products.
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Malgre l’importance des representants du genre Lotus en Algerie, leur statut symbiotique et la nature des Rhizobia qui leurs sont associes sont meconnus. Cette etude portant sur 39 plants de Lotus appartenant a 15 especes nous a permis de... more
Malgre l’importance des representants du genre Lotus en Algerie, leur statut symbiotique et la nature des Rhizobia qui leurs sont associes sont meconnus. Cette etude portant sur 39 plants de Lotus appartenant a 15 especes nous a permis de verifier qu’ils sont tous nodules et fixateurs d’azote et d’isoler a partir de leurs nodules 38 souches de BNL (Bacteries Nodulant les Legumineuses) qui ont ete authentifiees. Le sequencage du gene de l’ARNr 16S de ces 38 souches de Rhizobia montre une predominance de souches du genre Mesorhizobium represente par 10 especes parmi lesquelles M. erdmanii, M. ciceri et M. jarvisii se sont montrees les plus importantes. La nodulation des especes de Lotus examinees est assuree dans une moindre mesure par des souches des genres Bradyrhizobium et Ensifer, tous deux representes par deux especes. Cette etude a permis, d’une part, de reveler la diversite des Rhizobia associes aux Lotus d’Algerie, et d’autre part, de mettre en evidence une faible implication dans la nodulation des ...
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Twenty seven rhizobial strains associated with Acacia saligna grown in northern and southern Algeria were characterized, including generation time, host-range, the 16S rRNA gene and 16S–23S rRNA intergenic spacer restriction patterns, 16S... more
Twenty seven rhizobial strains associated with Acacia saligna grown in northern and southern Algeria were characterized, including generation time, host-range, the 16S rRNA gene and 16S–23S rRNA intergenic spacer restriction patterns, 16S rRNA gene sequence analysis and tolerance to salinity and drought. Cross inoculation tests indicated that 11 slow-growing isolates from northern nurseries were able to nodulate introduced Australian acacias exclusively, whereas 16 fast-growing isolates, mainly from southern nurseries, were capable of also nodulating native acacias. Restriction patterns and sequence analysis of the 16S rRNA gene showed that strains of the first group belonged to Bradyrhizobium while strains of the second group were related to Sinorhizobium meliloti and Rhizobium gallicum. Interestingly, five strains of the first group formed a distinct cluster phylogenetically close to Bradyrhizobium betae, a non-nodulating species causing tumour-like deformations in sugar beet roots. Bradyrhizobium strains were in general more sensitive to NaCl and PEG than the S. meliloti and R. gallicum representatives. Among the latter, strains S. meliloti BEC1 and R. gallicum DJA2 were able to tolerate up to 1M NaCl and 20% PEG. This, together with their wide host-range among Acacia species, make them good candidates for developing inoculants for A. saligna and other acacia trees growing in arid areas.
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Cent quarante quatre plants d'Acacia saligna (Labbil.) Wendl recueils au niveau de douze pépinières du nord et du sud du pays se sont révélés dans leur grande majorité nodulés et fixateurs d'azote. Cette espèce introduite dans un... more
Cent quarante quatre plants d'Acacia saligna (Labbil.) Wendl recueils au niveau de douze pépinières du nord et du sud du pays se sont révélés dans leur grande majorité nodulés et fixateurs d'azote. Cette espèce introduite dans un passé relativement récent est donc capable de s'associer avec des souches de Rhizobia autochtones pour former une symbiose fixatrice d'azote. Les performances symbiotiques des plants des pépinières du nord du pays se sont révélées très nettement supérieures à celles des plants des pépinières du sud vraisemblablement en raison de la nature des souches qui lui sont associées au niveau de ces régions. En effet, les souches extraites des plants provenant des pépinières du nord sont majoritairement à croissance lente et ont présenté un spectre d'hôte étroit tandis que les souches isolées à partir des plants des pépinières du sud se sont révélées toutes à croissance rapide et ont montré un spectre d'hôte plus large. Ces résultats prélimina...
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Biological and phytogeographical diversity for different levels of salinity in the region of Chott-Ech-Chergui (South-West of Algeria).-The Algerian halophilic areas have been subject to few studies, which remain fragmented. If their... more
Biological and phytogeographical diversity for different levels of salinity in the region of Chott-Ech-Chergui (South-West of Algeria).-The Algerian halophilic areas have been subject to few studies, which remain fragmented. If their floristic, pedological and phytogeographical characterization begins to be better clarified, studies related to changes in the flora and vegetation along a salinity gradient are, however, much rarer. The aim of this present work was to survey, at least partly, such changes in one of the largest saline lakes in Algeria known as the Chott-Ech-Chergui. The a priori surprising results are interesting because they show that, regardless of vegetation type and salinity degree, diversity indices are relatively high. They have the same value, when not larger, as their counterparts in steppe and unsalted presaharan areas. This contrasts with the obvious homogeneity of the landscape dominated by chamaephytes. In reality, it appears that conventional indices such as the Shannon index show here a limit in the conditions of their application. This peculiarity, although known, is rarely mentioned in the scientific literature. The evocation of this methodological problem reinforces the interest of the present work. RÉSUMÉ.-Les zones halophiles algériennes ont fait l'objet de quelques études, qui restent parcellaires. Si leur caractérisation floristique, pédologique et phytogéographique commence à se dégager, les études se rapportant aux changements de la flore et de la végétation le long d'un gradient de salinité sont par contre beaucoup plus rares. Le présent travail se propose de combler, au moins en partie, cette lacune dans l'un des plus grands Chotts algériens, en l'occurrence le Chott-Ech-Chergui. Les résultats, a priori surprenants, sont intéressants car ils montrent que, quel que soit le type de végétation et le taux de salinité, les indices de diversité sont relativement élevés. Ils sont du même ordre de grandeur, sinon plus grands que leurs homologues des zones steppiques et présahariennes non salées. Ceci s'accorde mal avec l'évidente homogénéité du paysage dominé par les chamaéphytes. En réalité, il apparaît que les indices classiques comme l'indice de Shannon montrent ici une limite de leurs conditions d'application. Cette particularité, bien que connue, est rarement évoquée au niveau de la littérature scientifique. L'évocation de ce problème méthodologique, renforce l'intérêt du présent travail.
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Describing and conserving ecological interactions woven into ecosystems is one of the great challenges of the 21st century. Here, we present a unique dataset compiling the biotic interactions between two ecologically and economically... more
Describing and conserving ecological interactions woven into ecosystems is one of the great challenges of the 21st century. Here, we present a unique dataset compiling the biotic interactions between two ecologically and economically important taxa: ground beetles (Coleoptera: Carabidae) and fungi. The resulting dataset contains the carabid-fungus associations collected from 392 scientific publications, 129 countries, mostly from the Palearctic region, published over a period of 200 years. With an updated taxonomy to match the currently accepted nomenclature, 3,378 unique associations among 5,564 records were identified between 1,776 carabid and 676 fungal taxa. Ectoparasitic Laboulbeniales were the most frequent fungal group associated with carabids, especially with Trechinae. The proportion of entomopathogens was low. Three different formats of the data have been provided along with an interactive data digest platform for analytical purposes. Our database summarizes the current kn...
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The immobilization of crude laccase from Trametes pubescens by glutaraldehyde crosslinking prior to entrapment into Ca-alginate beads increased the immobilization yield by 30% and reduced the leaking by 7-fold compared to the... more
The immobilization of crude laccase from Trametes pubescens by glutaraldehyde crosslinking prior to entrapment into Ca-alginate beads increased the immobilization yield by 30% and reduced the leaking by 7-fold compared to the immobilization with no crosslinking. The performance of the newly developed biocatalyst to degrade Bisphenol A (BPA) from aqueous solutions was tested. Thus, operating at optimal conditions (i.e. pH 5, 30 °C, 20 mg L BPA and 1500 U L laccase), a BPA removal higher than 99% in 2 h was achieved. This value is higher than those reported to date for BPA removal by immobilized laccases. In addition, the biocatalyst was able to remove BPA in 10 successive batches with an efficiency higher than 70% at the end of the last batch. BPA adsorption on the alginate beads was negligible, therefore BPA removal was only due to laccase action. Moreover, Fourier-transform Infrared (FTIR) spectroscopy suggested BPA transformation by laccase.
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The immobilization of crude laccase from Trametes pubescens by glutaraldehyde crosslinking prior to entrapment into Ca-alginate beads increased the immobilization yield by 30% and reduced the leaking by 7-fold compared to the... more
The immobilization of crude laccase from Trametes pubescens by glutaraldehyde crosslinking prior to entrapment into Ca-alginate beads increased the immobilization yield by 30% and reduced the leaking by 7-fold compared to the immobilization with no crosslinking. The performance of the newly developed biocatalyst to degrade Bisphenol A (BPA) from aqueous solutions was tested. Thus, operating at optimal conditions (i.e. pH 5, 30 °C, 20 mg L BPA and 1500 U L laccase), a BPA removal higher than 99% in 2 h was achieved. This value is higher than those reported to date for BPA removal by immobilized laccases. In addition, the biocatalyst was able to remove BPA in 10 successive batches with an efficiency higher than 70% at the end of the last batch. BPA adsorption on the alginate beads was negligible, therefore BPA removal was only due to laccase action. Moreover, Fourier-transform Infrared (FTIR) spectroscopy suggested BPA transformation by laccase.
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Our third contribution to the checklist of Algerian fungi is dedicated to Labouls (Laboulbeniales, Laboulbeniomycetes) an a typical and very diversified group of microscopic fungi that unsure their nutrition and/or dispersal by being... more
Our third contribution to the checklist of Algerian fungi is dedicated to Labouls (Laboulbeniales, Laboulbeniomycetes) an a typical and very diversified group of microscopic fungi that unsure their nutrition and/or dispersal by being insect ectoparasites. By screening all available bibliographic sources and herbaria catalogues it was possible to delineate 66 species belonging to 26 genera that occurs in Algeria. Additionally a list of 8 erroneous or doubtful records unsupported by literature and/or herbarium material is provided. This checklist is the first comprehensive species list fully dedicated to Algerian Laboulbeniales.
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Abstract: Despite more than two centuries of almost uninterrupted studies of the Algerian lichen flora, its diversity, ecology and biogeography remain much under-explored. Following the publication of our historical overview of... more
Abstract: Despite more than two centuries of almost uninterrupted studies of the Algerian lichen flora, its diversity, ecology and biogeography remain much under-explored. Following the publication of our historical overview of lichenological exploration of Algeria (1798-2013) and an annotated bibliography of 171 titles in 2015, it was thought necessary to provide a basis for future studies in the form of a checklist of Algerian lichens and lichenicolous fungi. In all, 1051 lichen taxa and 43 species of lichenicolous and allied fungi are listed, and their synonyms used in publications on Algerian lichens are provided. An attempt has also been made to provide basic biogeographical data.
Research Interests:
The immobilization of crude laccase from Trametes pubescens by glutaraldehyde crosslinking prior to entrapment into Ca-alginate beads increased the immobilization yield by 30% and reduced the leaking by 7-fold compared to the... more
The immobilization of crude laccase from Trametes pubescens by glutaraldehyde crosslinking prior to entrapment into Ca-alginate beads increased the immobilization yield by 30% and reduced the leaking by 7-fold compared to the immobilization with no crosslinking. The performance of the newly developed biocatalyst to degrade Bisphenol A (BPA) from aqueous solutions was tested. Thus, operating at optimal conditions (i.e. pH 5, 30 °C, 20mg L-1 BPA and 1500 U L-1 laccase), a BPA removal higher than 99% in 2 h was achieved. This value is higher than those reported to date for BPA removal by immobilized laccases. In addition, the biocatalyst was able to remove BPA in 10 successive batches with an e?ciency higher than 70% at the end of the last batch. BPA adsorption on the alginate beads was negligible, therefore BPA removal was only due to laccase action. Moreover, Fourier-transform Infrared (FTIR) spectroscopy suggested BPA transformation by laccase.
Informations on Algerian mycobiota are scattered through a wide array of journals, books, dissertations and the lack of comprehensive catalogs or checklists makes difficult to apprehend it diversity. By screening all available... more
Informations on Algerian mycobiota are scattered through a wide array of journals, books, dissertations and the lack of comprehensive catalogs or checklists makes difficult to apprehend it diversity. By screening all available bibliographic sources and herbaria catalogues it was possible to delineate 97 species belonging to 31 genera and from which 9 species have not been yet reported in the literature for Algeria. This checklist is the first comprehensive species list fully dedicated to Algerian Protozoan Fungal Analogues.
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The electrochemical oxidation of the neonicotinoid pesticide thiamethoxam (TMX) on a boron-doped diamond (BDD) anode was investigated. The effect of several operating parameters such as supporting electrolyte (0.025-0.1 M Na 2 SO 4 , 0.1... more
The electrochemical oxidation of the neonicotinoid pesticide thiamethoxam (TMX) on a boron-doped diamond (BDD) anode was investigated. The effect of several operating parameters such as supporting electrolyte (0.025-0.1 M Na 2 SO 4 , 0.1 M NaCl), current density (4–40 mA cm −2), TMX concentration (1–10 mg L −1 of active ingredient in a commercial formulation) and initial solution pH (3–11) on degradation was evaluated. The apparent rate constant of a pseudo-first order kinetic model was found to increase with increasing (i) current density (from 0.036 to 1 min −1 at 4 and 40 mA cm −2 , 2 mg L −1 TMX and 0.1 M Na 2 SO 4) and (ii) Na 2 SO 4 concentration (from 0.037 to 0.25 min −1 at 0.025 and 0.1 M Na 2 SO 4 , 2 mg L −1 TMX and 16 mA cm −2 current density) and decreasing (iii) TMX concentration (from 0.05 to 0.73 min −1 at 10 and 1 mg L −1 TMX, 0.1 M Na 2 SO 4 and 16 mA cm −2 current density) and (iv) initial solution pH (from 0.017 to 2.13 at pH 11 and 3, 0.1 M Na 2 SO 4 , 2 mg L −1 TMX and 16 mA cm −2 current density). Experiments in actual matrices, such as secondary treated wastewater and bottled water, resulted in lower kinetics (0.02 and 0.04 min −1 , respectively) than in pure water (0.22 min −1), signifying competitive interactions between TMX and the matrix constituents. Of the latter, organic matter (1–15 mg L −1 in the form of humic acid), bicarbonates (>100 mg L −1) and chlorides (>100 mg L −1) all had a detrimental effect on degradation. The rate constant of TMX degradation in pure water was reduced by 82%, 71% and 36% in the presence of 15 mg L −1 humic acid or 500 mg L −1 bicarbonates or 500 mg L −1 chlorides, respectively. Fast TMX degradation (i.e. complete removal of 2 mg L −1 TMX in 20 min at 16 mA cm −2 , 0.1 M Na 2 SO 4 , in pure water) is accompanied by slower mineralization (i.e. 91% total organic carbon removal at 120 min), indicating the formation of more resistant transformation by-products.
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Malgré l'importance des représentants du genre Lotus en Algérie, leur statut symbiotique et la nature des rhizobia qui leurs sont associés sont méconnus. Cette étude portant sur 39 plants de Lotus appartenant a ` 15 espèces nous a permis... more
Malgré l'importance des représentants du genre Lotus en Algérie, leur statut symbiotique et la nature des rhizobia qui leurs sont associés sont méconnus. Cette étude portant sur 39 plants de Lotus appartenant a ` 15 espèces nous a permis de vérifier qu'ils sont tous nodulés et fixateurs d'azote et d'isoler a ` partir de leurs nodules 38 souches de bactéries nodulant les légumineuses qui ont été authentifiées. Le séquençage du gène de l'ARNr 16 S de ces 38 souches de rhizobia montre une prédominance de souches du genre Mesorhizobium représenté par 10 espèces parmi lesquelles M. erdmanii, M. ciceri et M. jarvisii se sont montrées les plus importantes. La nodulation des espèces de Lotus examinées est assurée dans une moindre mesure par des souches des genres Bradyrhizobium et Ensifer, tous deux représentés par deux espèces. Cette étude a permis, d'une part, de révéler la diversité des rhizobia associés aux Lotus d'Algérie, et d'autre part, de mettre en évidence une faible implication dans la nodulation des souches du genre Bradyrhizobium et l'absence de celles de l'espèce Mesorhizobium loti, deux groupes de rhizobia considérés comme les microsymbiotes les plus communs chez les représentants du genre Lotus. Abstract: Despite the importance of the genus Lotus representatives in Algeria, their symbiotic status and the nature of associated rhizobia are unknown. This study on 39 Lotus plants belonging to 15 species showed that they are all nodulated and nitrogen-fixing and allowed the isolation of 38 authenticated strains of bacteria nodulating legumes. Analysis of 16 S rRNA gene sequences of these strains indicated a predominance of the strains of the genus Mesorhizobium represented by 10 species among which M. erdmanii, M. ciceri, and M. jarvisii are the most frequent. Nodulation of the examined Lotus species is assured in a lesser extent by strains of the genus Bradyrhizobium and genus Ensifer, both represented by two species. On one hand, this study revealed a part of the diversity of the rhizobia associated with the Lotus of Algeria, and on the other hand, highlighted a low involvement in the nodula-tion of these strains of the genus Bradyrhizobium as well as the absence of those of the species Mesorhizobium loti, two groups of rhizobia considered as the most common microsymbionts within the representatives of the genus Lotus.
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Ben Zetta et al.: Effects of pre-germination treatments, salt and water stresses on germination of two Acacia species-355-APPLIED ECOLOGY AND ENVIRONMENTAL RESEARCH 15(4):355-368. Abstract. Acacia ehrenbergiana Hayne and Acacia seyal Del.... more
Ben Zetta et al.: Effects of pre-germination treatments, salt and water stresses on germination of two Acacia species-355-APPLIED ECOLOGY AND ENVIRONMENTAL RESEARCH 15(4):355-368. Abstract. Acacia ehrenbergiana Hayne and Acacia seyal Del. are two desert trees of the Algerian Sahara that for a long time were confused. These two species present high potentials for desert areas rehabilitation therefore for successful seed germination and establishment three pre-germination treatments (manual scarification, boiling water and concentrated sulphuric acid) were used to overcome seeds dormancy. Once the optimal conditions are determined, we examined the effects of two abiotic stresses (salinity and water deficiency) on their seeds germination using eight levels of salinity (0, 50, 100, 150, 200, 250, 300 and 350mM of NaCl) and six concentrations of PEG 6000 (0,-2,-4,-6,-8 and-10 bars) on Acacia ehrenbergiana Hayne and Acacia seyal Del. Germination rate and mean germination time were calculated and data were subjected to analysis of variance (ANOVA) followed by Newman-Keuls test. Our results show that manual scarification and sulphuric acid had significant effects on the seeds germination of Acacia ehrenbergiana Hayne meanwhile, only sulphuric acid enhanced Acacia seyal Del. seeds germination. Under salt and water stresses, the germination rate and mean germination time of Acacia ehrenbergiana Hayne were less affected than those of Acacia seyal Del. Therefore manual scarification and sulphuric acid treatments could be applied and adopted at laboratory level or even at nurseries to raise plants germination and plantations establishment for desert areas rehabilitation. Thus, Acacia ehrenbergiana Hayne seems to be more suitable for massive propagation as it demonstrates resilience when facing harsh abiotic stresses (salt and water stresses).
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SUMMARY.— Biological and phytogeographical diversity for different levels of salinity in the region of Chott-Ech-Chergui (SouthWest of Algeria).— The Algerian halophilic areas have been subject to few studies, which remain fragmented. If... more
SUMMARY.— Biological and phytogeographical diversity for different levels of salinity in the region of Chott-Ech-Chergui (SouthWest of Algeria).— The Algerian halophilic areas have been subject to few studies, which remain fragmented. If their floristic, pedological and phytogeographical characterization begins to be better clarified, studies related to changes in the flora and vegetation along a salinity gradient are, however, much rarer. The aim of this present work was to survey, at least partly, such changes in one of the largest saline lakes in Algeria known as the Chott-Ech-Chergui. The a priori surprising results are interesting because they show that, regardless of vegetation type and salinity degree, diversity indices are relatively high. They have the same value, when not larger, as their counterparts in steppe and unsalted presaharan areas. This contrasts with the obvious homogeneity of the landscape dominated by chamaephytes. In reality, it appears that conventional indices such as the Shannon index show here a limit in the conditions of their application. This peculiarity, although known, is rarely mentioned in the scientific literature. The evocation of this methodological problem reinforces the interest of the present work. RÉSUMÉ.— Les zones halophiles algériennes ont fait l'objet de quelques études, qui restent parcellaires. Si leur caractérisation floristique, pédologique et phytogéographique commence à se dégager, les études se rapportant aux changements de la flore et de la végétation le long d'un gradient de salinité sont par contre beaucoup plus rares. Le présent travail se propose de combler, au moins en partie, cette lacune dans l'un des plus grands Chotts algériens, en l'occurrence le Chott-Ech-Chergui. Les résultats, a priori surprenants, sont intéressants car ils montrent que, quel que soit le type de végétation et le taux de salinité, les indices de diversité sont relativement élevés. Ils sont du même ordre de grandeur, sinon plus grands que leurs homologues des zones steppiques et présahariennes non salées. Ceci s'accorde mal avec l'évidente homogénéité du paysage dominé par les chamaéphytes. En réalité, il apparaît que les indices classiques comme l'indice de Shannon montrent ici une limite de leurs conditions d'application. Cette particularité, bien que connue, est rarement évoquée au niveau de la littérature scientifique. L'évocation de ce problème méthodologique, renforce l'intérêt du présent travail.
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BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofit publishers, academic institutions, research libraries, and research funders in the common goal of maximizing access to... more
BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofit publishers, academic institutions, research libraries, and research funders in the common goal of maximizing access to critical research.
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Leucaena leucocephala, une légumineuse ligneuse originaire du Mexique introduite en Algérie à la fin du 19ème siècle (1850) est aujourd’hui une composante importante de la flore arborée locale. Cet arbre qui est souvent qualifié « d’arbre... more
Leucaena leucocephala, une légumineuse ligneuse originaire du Mexique introduite en Algérie à la fin du 19ème siècle (1850) est aujourd’hui une composante importante de la flore arborée locale. Cet arbre qui est souvent qualifié « d’arbre miracle » en raison de ses nombreuses qualités parmi lesquelles sa croissance rapide, sa tolérance à la sécheresse et à la salinité, sa valeur fourragère et son statut d’espèce pionnière. Dans l’optique d’améliorer, au niveau des pépinières, le pouvoir fixateur d’azote de l’espèce, nous avons étudié la prévalence de la symbiose à rhizobia chez cette espèce et la nature des microsymbiotes qui lui sont associés.
Acacia tortilis subsp. raddiana (A. raddiana) est la légumineuse ligneuse la plus répandue dans les régions désertiques d’Algérie, en tant qu’espèce bien adaptée, elle constitue un potentiel pour le boisement et/ou le reboisement de ces... more
Acacia tortilis subsp. raddiana (A. raddiana) est la légumineuse ligneuse la plus répandue dans les régions désertiques d’Algérie, en tant qu’espèce bien adaptée, elle constitue un potentiel pour le boisement et/ou le reboisement de ces régions. Sacapacité d’établir une symbiose fixatrice d’azote avec les rhizobia constitue un caractère important pour son développement et son adaptation aux conditions du milieu
The Bulletin of the Society of Natural History of North Africa regularly published between 1909 and the 1970s, nearly 1800 articles dealing mainly with the fauna and flora of the countries of North Africa. The 67 volumes of this review... more
The Bulletin of the Society of Natural History of North Africa regularly published between 1909 and the 1970s, nearly 1800 articles dealing mainly with the fauna and flora of the countries of North Africa. The 67 volumes of this review constitute a considerable source of information for the knowledge of the biodiversity of North Africa.
Unfortunately, this documentary source is relatively unknown and under-used due to the lack of tables listing the papers published by this bulletin.
To compensate this lack we aimed to publish general tables of all the articles published in the Bulletin of the Natural History Society of North Africa as well as an index listing the subjects, genera and species treated by this journal.
Unfortunately, this documentary source is relatively unknown and under-used due to the lack of tables listing the papers published by this bulletin.
To compensate this lack we aimed to publish general tables of all the articles published in the Bulletin of the Natural History Society of North Africa as well as an index listing the subjects, genera and species treated by this journal.