Khalid OUFDOU - Academia.edu (original) (raw)
Papers by Khalid OUFDOU
International Journal of Molecular Sciences, Jan 10, 2024
Gesunde Pflanzen, Nov 16, 2023
Archives of Phytopathology and Plant Protection
Environmental Monitoring and Assessment
Soil and mine tailings are unreceptive to plant growth representing an imminent threat to the env... more Soil and mine tailings are unreceptive to plant growth representing an imminent threat to the environment and resource sustainability. Using indigenous plants and their associated rhizobacteria to restore mining sites would be an eco-friendly solution to mitigate soil-metal toxicity. Soil prospection from Draa Sfar and Kettara mining sites in Morocco was carried out during different seasons for native plant sampling and rhizobacteria screening. The sites have been colonized by fifteen tolerant plant species having different capacities to accumulate Cu, Zn, and P in their shoots/root systems. In Draa Sfar mine, Suaeda vera J.F. Gmel., Sarcocornia fruticosa (L.) A.J. Scott., and Frankenia corymbosa Desf. accumulated mainly Cu (more than 90 mg kg −1 ), Atriplex halimus L. accumulated Zn (mg kg −1 ), and Frankenia corymbosa Desf. accumulated Pb (14 mg kg −1 ). As for Kettara mine, Aizoon canariense L. mainly accumulated Zn (270 mg kg −1 ), whereas Forsskalea tenacissima L. was the best shoot Cu accumulator with up to 50 mg kg −1 , whereas Cu accumulation in roots was 21 mg kg −1 . The bacterial screening revealed the strains’ abilities to tolerate heavy metals up to 50 mg kg −1 Cu, 250 mg kg −1 Pb, and 150 mg kg −1 Zn. Isolated strains belonged mainly to Bacillaceae (73.33%) and Pseudomonadaceae (10%) and expressed different plant growth–promoting traits, alongside their antifungal activity. Results from this study will provide an insight into the ability of native plants and their associated rhizobacteria to serve as a basis for remediation-restoration strategies.
Contexte: La deficience en phosphore (P) est l'une des nombreuses contraintes environnemental... more Contexte: La deficience en phosphore (P) est l'une des nombreuses contraintes environnementales qui limitent la production des legumineuses dans la region du Haouz. Ceci exige de chercher des souches de rhizobia qui pourraient, par l’association symbiotique, conferer aux plantes de haricot (Phaseolus vulgaris) une tolerance relative au deficit en P et ameliorer sa production sous cette contrainte. L’objectif de ce travail c’est l’etude de l’effet de la deficience phosphatee sur les parametres de croissance et de nodulation chez ces combinaisons symbiotiques ainsi que l’evaluation des activites phosphatases et phytases au niveau des nodules, des racines et des feuilles des plantes de haricot inoculees par des souches de rhizobia et cultivees sous nutrition phosphatee limitante. [br/] Methodes: Dans cette optique, nous avons etudie la variation d’utilisation du phosphore chez le haricot sous des conditions semicontrolees. Ainsi, l’etude comparative des interactions symbiotiques a ...
The Mediterranean fruit fly, Ceratitis capitata (Diptera: Tephritidae), is considered a key pest ... more The Mediterranean fruit fly, Ceratitis capitata (Diptera: Tephritidae), is considered a key pest in fresh fruit and citrus production in the Mediterranean Bassin. Nowadays, it is being studied the use of several ecological methods against this pest in some Mediterranean countries (Spain, Morocco and Tunisia), like the Sterile Insect Technique (SIT), the classical biological control (CBC) and the search for native parasitoids. Two exotic larval - pupal parasitoids of fruit-flies have been imported by the IVIA to Spain: Diachasmimorpha tryoni and D. longicaudata. As it occurs in other countries, in Spain it is being studied the combined use of the SIT and overflooding releases of parasitoids to combat Medfly populations. To achieve this, only one parasitoid species is usually mass reared and released. Over the last two years we have been analyzing the competitiveness of D. longicaudata and D. tryoni in order to choose the species to be used together the SIT for the integrated control ...
Research & Reviews: Journal of Botanical Sciences, 2017
The present study was undertaken to investigate the plant growth promoting traits of a PGPR P. fl... more The present study was undertaken to investigate the plant growth promoting traits of a PGPR P. fluorescens and P. putida like production of Indoleacetic Acid (IAA), siderophore and phosphate solubilization. Plant growth-promoting properties of the two isolates were undertaken for their ability to produce siderophore, indole acetic acid and phosphate solubilization activity. The Indole-3-acetic acid and several other tryptophan (Trp) derivatives were separated by HPLC and quantified according to their fluorescence. On the other hand and in function of the two different types of root response to Fe deficiency (strategies), the isolates were tested for their effect on seed germination, seedling growth of Lens culinaris (strategy II) and Hordeum vulgar (strategy I) under gnotobiotic conditions and for tryptophan (Trp)-dependent IAA production. Both P. fluorescens and P. putida were shown to produce 3-indole-acetic acid (IAA) in vitro, at concentrations of 89 µg.ml-1 and 116 µg.ml-1, res...
Environmental Technology & Innovation, 2021
Abstract The present work deals with the phytotoxicity and the genotoxicity of three heavy metals... more Abstract The present work deals with the phytotoxicity and the genotoxicity of three heavy metals, namely copper, lead, and zinc on Medicago sativa seeds germination. Indeed, the role of metallo-resistant bacteria in lessening heavy metal toxicity was investigated. For this purpose, solutions of Cu, Pb, and Zn were used at the rate of 0.5, 1, 1.5, 2, and 2.5 mM for 4 d, along with untreated control using distilled water. The obtained findings displayed the stronger inhibitory effect of heavy metals on the germination and rhizogenesis process as well as a significant mito-depressive effect in the meristematic cells. For instance, Cu at the rate of 2.5 mM inhibited seed germination by 95 %, root elongation fell from 2.25 (in the control) to 0.14, while the mitotic index was reduced by 155%. Moreover, inoculation with metallo-resistant bacteria attenuated heavy metal toxicity, increased germination, rhizogenesis, mitotic index, and thus plant early growth. Metallo-resistant rhizobacteria inoculation improved the germination percentage by 40 % in the case of Cu and by 24 % in the case of Zn. The overall results suggest the cytotoxicity and the genotoxicity potential of Cu, Pb, and Zn on plants even at low concentrations. Furthermore, metallo-resistant bacteria application lessened heavy metal toxicity. This study confirms the suitability of M. sativa as a plant for the phytoremediation processes.
Gesunde Pflanzen, 2020
The use of composts appears to be a promising strategy to promote plant growth performance and to... more The use of composts appears to be a promising strategy to promote plant growth performance and to enhance soil fertility under field conditions. The objective of the present study was to select the best organic amendment able to enhance garlic growth, yield, physiological and biochemical parameters, as well as to improve soil fertility. The experiment was carried out under field conditions using three treatments: Control (C), Compost 1: horse manure-green waste (C1) and Compost 2: olive pomace-green waste (C2). To evaluate the effects of the application of the two composts on garlic growth, soil fertility and plant physiological, biochemical and nutritional traits were measured. The results showed that C1 decreased soil pH compared to the control, while electrical conductivity increased considerably for C2. In addition, nitrogen (N), phosphorus (P), total organic carbon (TOC) were significantly increased in soil for C1 followed by C2. The increase percentages of shoots dry biomass with C1 and C2 compared to the control were 64.9% and 158%, respectively. Moreover, for bulbs yield, the composts C1 and C2 produced 46.5% and 41.9%, respectively. Besides, physiological and biochemical parameters of garlic were improved by C1 and C2 compared to control plants. Moreover, antioxidant enzymes such as PPO and POX, decreased significantly in treated plants. Furthermore, mineral analyses showed that C1 and C2 significantly improved minerals contents in leaves and bulbs compared to the control. The results demonstrate the potential of horse manure-green waste compost for the improvement and optimization of soil fertility and crop productivity. This organic amendment could be an efficient practice and a potential bio-fertilizer to improve growth and development as well as biological agriculture of garlic production.
Gesunde Pflanzen, 2020
Alfalfa (Medicago sativa L.) is one of the most important forages and legume crops in the Mediter... more Alfalfa (Medicago sativa L.) is one of the most important forages and legume crops in the Mediterranean region, where extensive soil exploitation and low soil fertility are among the factor limiting its production. In this study, a field experiment was carried out in the semi-arid area of Morocco, in order to assess the influence of the individual and combined application of autochthonous arbuscular mycorrhizal fungi (AMF), rhizobium strain and green compost supply on alfalfa. Vegetative yield, physiological and biochemical traits were evaluated together with the associated changes in the soil’s physico-chemical parameters. The results show that AMF and rhizobium inoculation combined with compost application induced the greatest effect. This treatment increased the dry matter yield, leaves and nodules number, and AMF infection rate. Moreover, the combined use of these biofertilizers further enhanced stomatal conductance, photosystem II efficiency, photosynthetic pigments (chlorophyll and carotenoids), protein and sugar content along with the nutrients uptake (Phosphorus (P), Nitrogen (N), Potassium (K) and Calcium (Ca)). When compared with the initial soil status, the compost (10 t/ha) combined with AMF and rhizobium significantly improved the organic matter, N and P content, decreased soil pH and increased electrical conductivity. This treatment is also efficient in increasing soil glomalin content. This study demonstrated that the interaction between green waste compost, AMF and rhizobium inoculation could have important implications in alfalfa sustainable agriculture.
Crop and Pasture Science, 2019
Intercropping is a farming practice that fights pests and diseases and improves plant growth. The... more Intercropping is a farming practice that fights pests and diseases and improves plant growth. The use of plant growth-promoting rhizobacteria (PGPR) strains to boost the yield of intercrops constitutes a promising tool in agricultural practice. This study investigated the impact of single inoculation and co-inoculation with PGPR on plant biomass and phosphorus (P) and nitrogen (N) concentrations under different cropping systems. Two PGPR strains with different traits were selected: PGP13 (Rahnella aquatilis) and PS11 (Pseudomonas sp.). A greenhouse experiment was designed using durum wheat (Triticum durum L.) and faba bean (Vicia faba L.), sole cropped or intercropped, including four inoculation treatments: (i) uninoculated, (ii) inoculated with PS11 (iii) inoculated with PGP13, and (iv) co-inoculated with PS11 + PGP13. Co-inoculation under the intercropping system improved plant dry matter and enhanced bean pod and wheat spike weights to 685.83% and 385.83%, respectively, of the va...
International Journal of Acarology, 2018
Systematic and applied microbiology, Jan 3, 2017
Rhizobia are symbiotic nitrogen-fixing bacteria in root nodules of legumes. In Morocco, faba bean... more Rhizobia are symbiotic nitrogen-fixing bacteria in root nodules of legumes. In Morocco, faba bean (Vicia faba L.), which is the main legume crop cultivated in the country, is often grown in marginal soils of arid and semi-arid regions. This study examines the phenotypic diversity of rhizobia nodulating V. faba isolated from different regions in Morocco for tolerance to some abiotic stresses. A total of 106 rhizobia strains isolated from nodules were identified at the species level by analysing 16S rDNA. Additionally, for selected strains recA, otsA, kup and nodA fragments were sequenced. 102 isolates are likely to belong to Rhizobium leguminosarum or R. laguerreae and 4 isolates to Ensifer meliloti. All strains tolerating salt concentrations of 428 or 342mM NaCl as well as 127 or 99mM Na2SO4 were highly resistant to alkaline conditions (pH 10) and high temperature (44°C). Three strains: RhOF4 and RhOF53 (both are salt-tolerant) and RhOF6 (salt-sensitive) were selected to compare the...
Procedia Engineering, 2016
Abstract After nitrogen, phosphorus is the main element for plant growth. Most agricultural soils... more Abstract After nitrogen, phosphorus is the main element for plant growth. Most agricultural soils worldwide are deficient in phosphorus and therefore require a contribution of phosphorus for the plant needs. There is a continuing need to improve soil fertility, to increase yields and agricultural productivity. During the application of phosphate fertilizers, soluble phosphorus assimilated by plants is rare because of its precipitation and then become unavailable to the plant. Rhizospheric bacteria including the plant growth promoting rhizobacteria (PGPR) are of growing interest for their potential role in improving soil fertility and enhancing an increase of crop yields and their nutrients contents. These bacteria make the insoluble phosphorus in soluble forms during the application of phosphate fertilizers and make the phosphorus available to the plant. This work gives a review of methodology and techniques used for the research of phosphate solubilization bacteria (PSB), their molecular characterization and the biochemical mechanisms and genes tools involved in solubilization of phosphate and their relationships with symbiotic plants.
87 Des expériences ont été conduites en serre et en laboratoire pour mettre en évidence les effet... more 87 Des expériences ont été conduites en serre et en laboratoire pour mettre en évidence les effets du PNT sur le développement, la croissance et la nutrition d'arbres à usage multiple (Gliricidia sepium et Sesbania sesban) inoculés avec un champignon endomycorhizien (Glomus aggregatum). Ces effets ont été comparés à ceux du TSP utilisé comme engrais de référence. Le sol de Nioro (Sénégal) a été utilisé comme substrat de culture pour les arbres. Les résultats ont montré que le PNT a été le phosphate préférentiel; utilisé à la dose de 75 mg P.kg-1, il a été mieux utilisé par S. sesban chez lequel la hauteur, la biomasse et l'absorption des éléments majeurs (N, P, K) ont été améliorés surtout en présence du champignon mycorhizien. Cependant, la valorisation du PNT sur le sol de Nioro a modifié la diversité des rhizobiums naturellement présents dans le sol. Il faudrait donc veiller, si l'on veut valoriser le PNT, à ne pas perturber la diversité d'autres microorganismes c...
Au Maroc, durant la saison chaude, plusieurs ecosystemes aquatiques et surtout les lacs connaisse... more Au Maroc, durant la saison chaude, plusieurs ecosystemes aquatiques et surtout les lacs connaissent une croissance massive des cyanobacteries conduisant a la formation d'efflorescences. Ces cyanobacteries sont capables de produire une multitude de substances bioactives qui agissent positivement ou negativement sur d'autres organismes. L'objectif de ce travail est l'etude des effets du bloom a Microcystis aeruginosa sur certaines bacteries d'interet sanitaire, dans le lac-reservoir Lalla Takerkoust. Pour cela, nous avons realise in situ un suivi mensuel de cette cyanobacterie et des bacteries pendant 5 mois (juin a octobre 2004). La recherche de la toxicite de M. aeruginosa a ete egalement realisee par le biotest souris. Les resultats obtenus montrent que M. aeruginosa s'est installee avec une biomasse importante a partir du mois d'aout, puis qu'elle a presente un pic d'abondance de 1,4 x 10 6 cellules/ml en septembre. Le suivi des bacteries etudiees a montre que celles-ci presentent des abondances respectives importantes lors du pic de croissance de M. aeruginosa. L'abondance de Vibrio cholerae non-O1 atteint 1100 MPN/100ml au mois de septembre. En ce qui concerne les coliformes fecaux et les streptocoques fecaux indicateurs de contamination, leurs abondances augmentent relativement durant le bloom de M. aeruginosa. L'abondance de ces bacteries depasse les normes concernant les eaux destinees a l'alimentation humaine. En outre, la cyanobacterie M. aeruginosa entraine une mortalite des souris auxquelles sont injectees les cyanotoxines. Selon les directives concernant les eaux superficielles, les eaux du barrage Lalla Takerkoust necessitent un traitement au cours du bloom a M. aeruginosa.
Plant Microbes Symbiosis: Applied Facets, 2014
Plant symbiotic interactions with nitrogen-fixing bacteria could be used in agricultural and fore... more Plant symbiotic interactions with nitrogen-fixing bacteria could be used in agricultural and forest soils under harsh conditions and for land reclamation. These associations include rhizobia interacting with legumes species and the actinobacterium Frankia interacting with actinorhizal plants. These plants are distributed worldwide and suffer in many areas – especially in arid and semiarid regions from harsh biotic and abiotic conditions. Abiotic stress conditions include climatic conditions, soil characteristics, water and nutrient availability, salinity, and soil contamination by heavy metals, xenobiotics, and toxins. Thus, the improvement of symbiotic nitrogen fixation under stress conditions may rely on strategies devised to select more tolerant plant-bacteria associations and to use successfully efficient synergistic systems such as those involving mycorrhizal fungi and rhizobacteria, particularly plant growth-promoting rhizobacteria (PGPR). This chapter focuses on main stress conditions affecting plant-bacteria symbioses with emphasis on mechanisms that underpin plant resistance to stress. Biological strategies involving microbial inoculants aiming to protect and improve plant symbioses against detrimental effects of abiotic stresses so as to enhance the crop production in such conditions are discussed. In addition, plant-bacteria symbioses can also be used to promote the establishment of perennial vegetation that might limit the heavy metal pollution of soils and consequently represent an effective management procedure in disturbed soils. This chapter also focuses on main techniques successfully used for the purpose of land reclamation by plant-bacteria symbioses.
International Journal of Molecular Sciences, Jan 10, 2024
Gesunde Pflanzen, Nov 16, 2023
Archives of Phytopathology and Plant Protection
Environmental Monitoring and Assessment
Soil and mine tailings are unreceptive to plant growth representing an imminent threat to the env... more Soil and mine tailings are unreceptive to plant growth representing an imminent threat to the environment and resource sustainability. Using indigenous plants and their associated rhizobacteria to restore mining sites would be an eco-friendly solution to mitigate soil-metal toxicity. Soil prospection from Draa Sfar and Kettara mining sites in Morocco was carried out during different seasons for native plant sampling and rhizobacteria screening. The sites have been colonized by fifteen tolerant plant species having different capacities to accumulate Cu, Zn, and P in their shoots/root systems. In Draa Sfar mine, Suaeda vera J.F. Gmel., Sarcocornia fruticosa (L.) A.J. Scott., and Frankenia corymbosa Desf. accumulated mainly Cu (more than 90 mg kg −1 ), Atriplex halimus L. accumulated Zn (mg kg −1 ), and Frankenia corymbosa Desf. accumulated Pb (14 mg kg −1 ). As for Kettara mine, Aizoon canariense L. mainly accumulated Zn (270 mg kg −1 ), whereas Forsskalea tenacissima L. was the best shoot Cu accumulator with up to 50 mg kg −1 , whereas Cu accumulation in roots was 21 mg kg −1 . The bacterial screening revealed the strains’ abilities to tolerate heavy metals up to 50 mg kg −1 Cu, 250 mg kg −1 Pb, and 150 mg kg −1 Zn. Isolated strains belonged mainly to Bacillaceae (73.33%) and Pseudomonadaceae (10%) and expressed different plant growth–promoting traits, alongside their antifungal activity. Results from this study will provide an insight into the ability of native plants and their associated rhizobacteria to serve as a basis for remediation-restoration strategies.
Contexte: La deficience en phosphore (P) est l'une des nombreuses contraintes environnemental... more Contexte: La deficience en phosphore (P) est l'une des nombreuses contraintes environnementales qui limitent la production des legumineuses dans la region du Haouz. Ceci exige de chercher des souches de rhizobia qui pourraient, par l’association symbiotique, conferer aux plantes de haricot (Phaseolus vulgaris) une tolerance relative au deficit en P et ameliorer sa production sous cette contrainte. L’objectif de ce travail c’est l’etude de l’effet de la deficience phosphatee sur les parametres de croissance et de nodulation chez ces combinaisons symbiotiques ainsi que l’evaluation des activites phosphatases et phytases au niveau des nodules, des racines et des feuilles des plantes de haricot inoculees par des souches de rhizobia et cultivees sous nutrition phosphatee limitante. [br/] Methodes: Dans cette optique, nous avons etudie la variation d’utilisation du phosphore chez le haricot sous des conditions semicontrolees. Ainsi, l’etude comparative des interactions symbiotiques a ...
The Mediterranean fruit fly, Ceratitis capitata (Diptera: Tephritidae), is considered a key pest ... more The Mediterranean fruit fly, Ceratitis capitata (Diptera: Tephritidae), is considered a key pest in fresh fruit and citrus production in the Mediterranean Bassin. Nowadays, it is being studied the use of several ecological methods against this pest in some Mediterranean countries (Spain, Morocco and Tunisia), like the Sterile Insect Technique (SIT), the classical biological control (CBC) and the search for native parasitoids. Two exotic larval - pupal parasitoids of fruit-flies have been imported by the IVIA to Spain: Diachasmimorpha tryoni and D. longicaudata. As it occurs in other countries, in Spain it is being studied the combined use of the SIT and overflooding releases of parasitoids to combat Medfly populations. To achieve this, only one parasitoid species is usually mass reared and released. Over the last two years we have been analyzing the competitiveness of D. longicaudata and D. tryoni in order to choose the species to be used together the SIT for the integrated control ...
Research & Reviews: Journal of Botanical Sciences, 2017
The present study was undertaken to investigate the plant growth promoting traits of a PGPR P. fl... more The present study was undertaken to investigate the plant growth promoting traits of a PGPR P. fluorescens and P. putida like production of Indoleacetic Acid (IAA), siderophore and phosphate solubilization. Plant growth-promoting properties of the two isolates were undertaken for their ability to produce siderophore, indole acetic acid and phosphate solubilization activity. The Indole-3-acetic acid and several other tryptophan (Trp) derivatives were separated by HPLC and quantified according to their fluorescence. On the other hand and in function of the two different types of root response to Fe deficiency (strategies), the isolates were tested for their effect on seed germination, seedling growth of Lens culinaris (strategy II) and Hordeum vulgar (strategy I) under gnotobiotic conditions and for tryptophan (Trp)-dependent IAA production. Both P. fluorescens and P. putida were shown to produce 3-indole-acetic acid (IAA) in vitro, at concentrations of 89 µg.ml-1 and 116 µg.ml-1, res...
Environmental Technology & Innovation, 2021
Abstract The present work deals with the phytotoxicity and the genotoxicity of three heavy metals... more Abstract The present work deals with the phytotoxicity and the genotoxicity of three heavy metals, namely copper, lead, and zinc on Medicago sativa seeds germination. Indeed, the role of metallo-resistant bacteria in lessening heavy metal toxicity was investigated. For this purpose, solutions of Cu, Pb, and Zn were used at the rate of 0.5, 1, 1.5, 2, and 2.5 mM for 4 d, along with untreated control using distilled water. The obtained findings displayed the stronger inhibitory effect of heavy metals on the germination and rhizogenesis process as well as a significant mito-depressive effect in the meristematic cells. For instance, Cu at the rate of 2.5 mM inhibited seed germination by 95 %, root elongation fell from 2.25 (in the control) to 0.14, while the mitotic index was reduced by 155%. Moreover, inoculation with metallo-resistant bacteria attenuated heavy metal toxicity, increased germination, rhizogenesis, mitotic index, and thus plant early growth. Metallo-resistant rhizobacteria inoculation improved the germination percentage by 40 % in the case of Cu and by 24 % in the case of Zn. The overall results suggest the cytotoxicity and the genotoxicity potential of Cu, Pb, and Zn on plants even at low concentrations. Furthermore, metallo-resistant bacteria application lessened heavy metal toxicity. This study confirms the suitability of M. sativa as a plant for the phytoremediation processes.
Gesunde Pflanzen, 2020
The use of composts appears to be a promising strategy to promote plant growth performance and to... more The use of composts appears to be a promising strategy to promote plant growth performance and to enhance soil fertility under field conditions. The objective of the present study was to select the best organic amendment able to enhance garlic growth, yield, physiological and biochemical parameters, as well as to improve soil fertility. The experiment was carried out under field conditions using three treatments: Control (C), Compost 1: horse manure-green waste (C1) and Compost 2: olive pomace-green waste (C2). To evaluate the effects of the application of the two composts on garlic growth, soil fertility and plant physiological, biochemical and nutritional traits were measured. The results showed that C1 decreased soil pH compared to the control, while electrical conductivity increased considerably for C2. In addition, nitrogen (N), phosphorus (P), total organic carbon (TOC) were significantly increased in soil for C1 followed by C2. The increase percentages of shoots dry biomass with C1 and C2 compared to the control were 64.9% and 158%, respectively. Moreover, for bulbs yield, the composts C1 and C2 produced 46.5% and 41.9%, respectively. Besides, physiological and biochemical parameters of garlic were improved by C1 and C2 compared to control plants. Moreover, antioxidant enzymes such as PPO and POX, decreased significantly in treated plants. Furthermore, mineral analyses showed that C1 and C2 significantly improved minerals contents in leaves and bulbs compared to the control. The results demonstrate the potential of horse manure-green waste compost for the improvement and optimization of soil fertility and crop productivity. This organic amendment could be an efficient practice and a potential bio-fertilizer to improve growth and development as well as biological agriculture of garlic production.
Gesunde Pflanzen, 2020
Alfalfa (Medicago sativa L.) is one of the most important forages and legume crops in the Mediter... more Alfalfa (Medicago sativa L.) is one of the most important forages and legume crops in the Mediterranean region, where extensive soil exploitation and low soil fertility are among the factor limiting its production. In this study, a field experiment was carried out in the semi-arid area of Morocco, in order to assess the influence of the individual and combined application of autochthonous arbuscular mycorrhizal fungi (AMF), rhizobium strain and green compost supply on alfalfa. Vegetative yield, physiological and biochemical traits were evaluated together with the associated changes in the soil’s physico-chemical parameters. The results show that AMF and rhizobium inoculation combined with compost application induced the greatest effect. This treatment increased the dry matter yield, leaves and nodules number, and AMF infection rate. Moreover, the combined use of these biofertilizers further enhanced stomatal conductance, photosystem II efficiency, photosynthetic pigments (chlorophyll and carotenoids), protein and sugar content along with the nutrients uptake (Phosphorus (P), Nitrogen (N), Potassium (K) and Calcium (Ca)). When compared with the initial soil status, the compost (10 t/ha) combined with AMF and rhizobium significantly improved the organic matter, N and P content, decreased soil pH and increased electrical conductivity. This treatment is also efficient in increasing soil glomalin content. This study demonstrated that the interaction between green waste compost, AMF and rhizobium inoculation could have important implications in alfalfa sustainable agriculture.
Crop and Pasture Science, 2019
Intercropping is a farming practice that fights pests and diseases and improves plant growth. The... more Intercropping is a farming practice that fights pests and diseases and improves plant growth. The use of plant growth-promoting rhizobacteria (PGPR) strains to boost the yield of intercrops constitutes a promising tool in agricultural practice. This study investigated the impact of single inoculation and co-inoculation with PGPR on plant biomass and phosphorus (P) and nitrogen (N) concentrations under different cropping systems. Two PGPR strains with different traits were selected: PGP13 (Rahnella aquatilis) and PS11 (Pseudomonas sp.). A greenhouse experiment was designed using durum wheat (Triticum durum L.) and faba bean (Vicia faba L.), sole cropped or intercropped, including four inoculation treatments: (i) uninoculated, (ii) inoculated with PS11 (iii) inoculated with PGP13, and (iv) co-inoculated with PS11 + PGP13. Co-inoculation under the intercropping system improved plant dry matter and enhanced bean pod and wheat spike weights to 685.83% and 385.83%, respectively, of the va...
International Journal of Acarology, 2018
Systematic and applied microbiology, Jan 3, 2017
Rhizobia are symbiotic nitrogen-fixing bacteria in root nodules of legumes. In Morocco, faba bean... more Rhizobia are symbiotic nitrogen-fixing bacteria in root nodules of legumes. In Morocco, faba bean (Vicia faba L.), which is the main legume crop cultivated in the country, is often grown in marginal soils of arid and semi-arid regions. This study examines the phenotypic diversity of rhizobia nodulating V. faba isolated from different regions in Morocco for tolerance to some abiotic stresses. A total of 106 rhizobia strains isolated from nodules were identified at the species level by analysing 16S rDNA. Additionally, for selected strains recA, otsA, kup and nodA fragments were sequenced. 102 isolates are likely to belong to Rhizobium leguminosarum or R. laguerreae and 4 isolates to Ensifer meliloti. All strains tolerating salt concentrations of 428 or 342mM NaCl as well as 127 or 99mM Na2SO4 were highly resistant to alkaline conditions (pH 10) and high temperature (44°C). Three strains: RhOF4 and RhOF53 (both are salt-tolerant) and RhOF6 (salt-sensitive) were selected to compare the...
Procedia Engineering, 2016
Abstract After nitrogen, phosphorus is the main element for plant growth. Most agricultural soils... more Abstract After nitrogen, phosphorus is the main element for plant growth. Most agricultural soils worldwide are deficient in phosphorus and therefore require a contribution of phosphorus for the plant needs. There is a continuing need to improve soil fertility, to increase yields and agricultural productivity. During the application of phosphate fertilizers, soluble phosphorus assimilated by plants is rare because of its precipitation and then become unavailable to the plant. Rhizospheric bacteria including the plant growth promoting rhizobacteria (PGPR) are of growing interest for their potential role in improving soil fertility and enhancing an increase of crop yields and their nutrients contents. These bacteria make the insoluble phosphorus in soluble forms during the application of phosphate fertilizers and make the phosphorus available to the plant. This work gives a review of methodology and techniques used for the research of phosphate solubilization bacteria (PSB), their molecular characterization and the biochemical mechanisms and genes tools involved in solubilization of phosphate and their relationships with symbiotic plants.
87 Des expériences ont été conduites en serre et en laboratoire pour mettre en évidence les effet... more 87 Des expériences ont été conduites en serre et en laboratoire pour mettre en évidence les effets du PNT sur le développement, la croissance et la nutrition d'arbres à usage multiple (Gliricidia sepium et Sesbania sesban) inoculés avec un champignon endomycorhizien (Glomus aggregatum). Ces effets ont été comparés à ceux du TSP utilisé comme engrais de référence. Le sol de Nioro (Sénégal) a été utilisé comme substrat de culture pour les arbres. Les résultats ont montré que le PNT a été le phosphate préférentiel; utilisé à la dose de 75 mg P.kg-1, il a été mieux utilisé par S. sesban chez lequel la hauteur, la biomasse et l'absorption des éléments majeurs (N, P, K) ont été améliorés surtout en présence du champignon mycorhizien. Cependant, la valorisation du PNT sur le sol de Nioro a modifié la diversité des rhizobiums naturellement présents dans le sol. Il faudrait donc veiller, si l'on veut valoriser le PNT, à ne pas perturber la diversité d'autres microorganismes c...
Au Maroc, durant la saison chaude, plusieurs ecosystemes aquatiques et surtout les lacs connaisse... more Au Maroc, durant la saison chaude, plusieurs ecosystemes aquatiques et surtout les lacs connaissent une croissance massive des cyanobacteries conduisant a la formation d'efflorescences. Ces cyanobacteries sont capables de produire une multitude de substances bioactives qui agissent positivement ou negativement sur d'autres organismes. L'objectif de ce travail est l'etude des effets du bloom a Microcystis aeruginosa sur certaines bacteries d'interet sanitaire, dans le lac-reservoir Lalla Takerkoust. Pour cela, nous avons realise in situ un suivi mensuel de cette cyanobacterie et des bacteries pendant 5 mois (juin a octobre 2004). La recherche de la toxicite de M. aeruginosa a ete egalement realisee par le biotest souris. Les resultats obtenus montrent que M. aeruginosa s'est installee avec une biomasse importante a partir du mois d'aout, puis qu'elle a presente un pic d'abondance de 1,4 x 10 6 cellules/ml en septembre. Le suivi des bacteries etudiees a montre que celles-ci presentent des abondances respectives importantes lors du pic de croissance de M. aeruginosa. L'abondance de Vibrio cholerae non-O1 atteint 1100 MPN/100ml au mois de septembre. En ce qui concerne les coliformes fecaux et les streptocoques fecaux indicateurs de contamination, leurs abondances augmentent relativement durant le bloom de M. aeruginosa. L'abondance de ces bacteries depasse les normes concernant les eaux destinees a l'alimentation humaine. En outre, la cyanobacterie M. aeruginosa entraine une mortalite des souris auxquelles sont injectees les cyanotoxines. Selon les directives concernant les eaux superficielles, les eaux du barrage Lalla Takerkoust necessitent un traitement au cours du bloom a M. aeruginosa.
Plant Microbes Symbiosis: Applied Facets, 2014
Plant symbiotic interactions with nitrogen-fixing bacteria could be used in agricultural and fore... more Plant symbiotic interactions with nitrogen-fixing bacteria could be used in agricultural and forest soils under harsh conditions and for land reclamation. These associations include rhizobia interacting with legumes species and the actinobacterium Frankia interacting with actinorhizal plants. These plants are distributed worldwide and suffer in many areas – especially in arid and semiarid regions from harsh biotic and abiotic conditions. Abiotic stress conditions include climatic conditions, soil characteristics, water and nutrient availability, salinity, and soil contamination by heavy metals, xenobiotics, and toxins. Thus, the improvement of symbiotic nitrogen fixation under stress conditions may rely on strategies devised to select more tolerant plant-bacteria associations and to use successfully efficient synergistic systems such as those involving mycorrhizal fungi and rhizobacteria, particularly plant growth-promoting rhizobacteria (PGPR). This chapter focuses on main stress conditions affecting plant-bacteria symbioses with emphasis on mechanisms that underpin plant resistance to stress. Biological strategies involving microbial inoculants aiming to protect and improve plant symbioses against detrimental effects of abiotic stresses so as to enhance the crop production in such conditions are discussed. In addition, plant-bacteria symbioses can also be used to promote the establishment of perennial vegetation that might limit the heavy metal pollution of soils and consequently represent an effective management procedure in disturbed soils. This chapter also focuses on main techniques successfully used for the purpose of land reclamation by plant-bacteria symbioses.