In the current study, we investigated the impact of inoculation with a selected indigenous arbuscular mycorrhizal fungi (AMF) complex on the growth and physiology of carob plants at increasing levels ...of watering (25, 50, 75 and 100% field capacity). The following growth and stress parameters were monitored in carob seedlings after 6 months of growth and 2 months of applied drought stress: fresh and dry weight, root and shoot lengths, leaf surface area, relative water content, stomatal conductance and membrane stability. Chlorophyll a and b, total soluble sugars, proline and protein contents were also determined along with the activities of stress enzymes: Catalase, Peroxidase and Superoxide dismutase. The obtained results indicate that inoculation with the indigenous AMF complex has a positive impact on the plant’s growth as all the assessed parameters were significantly improved in the mycorrhizal plants. Additionally, our results show that mycorrhization contributes to the minimization of the impact of drought stress on the carob plants and allows a better adaptation to dry conditions.
Among the abiotic stresses, drought is the first environmental stress responsible for a decrease in agricultural production worldwide; it affects plants in various ways, including slowing down plant ...growth and disrupting its general physiology. Arbuscular mycorrhizal symbiosis and plant growth-promoting rhizobacteria (PGPR) are considered to be the bioameliorators of the plant’s resistance to water stress. The present study investigated the effects of inoculation with arbuscular mycorrhizal fungi (AMF) and PGPR on the water status and antioxidant enzyme activities of date palm seedlings grown under water stress conditions. The parameters related to the plant’s water status were significantly (p<0.05) higher in the plants treated with mycorrhizae and mycorrhizae + bacteria compared with their respective controls, especially under water stress conditions. The maximum proline content was obtained in plants inoculated with the AMF species and PGPR (combined) under severe water stress conditions reaching a value of 2.588 ± 0.034 in 25% field capacity, compared with 0.978 ± 0.024 for the control. In addition, the inoculated seedlings showed notably lower activities of superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), and glutathione S-transferase (GST) in response to severe water stress compared with nonmycorrhizal seedling. Overall, the arbuscular mycorrhizal symbiosis and PGPR bacteria inoculation could be promising methods to enhance date palm resistance against oxidative stress.
Agricultural yields are under constant jeopardy as climate change and abiotic pressures spread worldwide. Using rhizospheric microbes as biostimulants/biofertilizers is one of the best ways to ...improve agro-agriculture in the face of these things. The purpose of this experiment was to investigate whether a native arbuscular mycorrhizal fungi inoculum (AMF-complex) might improve caper (Capparis spinosa) seedlings’ nutritional status, their morphological/growth performance and photosynthetic efficiency under water-deficit stress (WDS). Thus, caper plantlets inoculated with or without an AMF complex (+AMF and −AMF, respectively) were grown under three gradually increasing WDS regimes, i.e., 75, 50 and 25% of field capacity (FC). Overall, measurements of morphological traits, biomass production and nutrient uptake (particularly P, K+, Mg2+, Fe2+ and Zn2+) showed that mycorrhizal fungi inoculation increased these variables significantly, notably in moderate and severe WDS conditions. The increased WDS levels reduced the photochemical efficiency indices (Fv/Fm and Fv/Fo) in −AMF plants, while AMF-complex application significantly augmented these parameters. Furthermore, the photosynthetic pigments content was substantially higher in +AMF seedlings than −AMF controls at all the WDS levels. Favorably, at 25% FC, AMF-colonized plants produce approximately twice as many carotenoids as non-colonized ones. In conclusion, AMF inoculation seems to be a powerful eco-engineering strategy for improving the caper seedling growth rate and drought tolerance in harsh environments.
The date, the palm tree (Phoenix dactylifera L.) is an important component of arid and semi-arid Mediterranean ecosystems, particularly in Morocco where it plays a considerable socio-economic and ...ecological role. This species is largely affected by desertification, global warming, and anthropic pressure. Salinity is a very worrying problem that negatively affects the growth and the physiological and biochemical activities of the date palm. In these arid zones, the main challenge is to develop new environmentally friendly technologies that improve crop tolerance to abiotic restraints including salinity. In this sense, Arbuscular mycorrhizal fungi (AMF) have received much attention due to their capability in promoting plant growth and tolerance to abiotic and biotic stresses. It is thus fitting that the current research work was undertaken to evaluate and compare the effects of native AMF on the development of the growth and tolerance of date palm to salt stress along with testing their role as biofertilizers. To achieve this goal, two complexes and two monospecific isolates of native and non-native AMF were used to inoculate date palm seedlings under saline stress (0 g·L−1 Na Cl, 10 g·L−1, and 20 g·L−1 Na Cl). The obtained results showed that salinity drastically affected the physiological parameters and growth of date palm seedlings, whilst the application of selected AMF significantly improved growth parameters and promoted the activities of antioxidant enzymes as a protective strategy. Inoculation with non-native AMF complex and monospecific isolates showed higher responses for all analyzed parameters when compared with the native complex and isolate. It therefore becomes necessary to glamorize the fungal communities associated with date palm for their use in the inoculation of Phoenix dactylifera L. seedlings.
In the current study, we investigated the impact of inoculation with a selected indigenous arbuscular mycorrhizal fungi (AMF) complex on the growth and physiology of carob plants at increasing levels ...of watering (25, 50, 75 and 100% field capacity). The following growth and stress parameters were monitored in carob seedlings after 6 months of growth and 2 months of applied drought stress: fresh and dry weight, root and shoot lengths, leaf surface area, relative water content, stomatal conductance and membrane stability. Chlorophyll a and b, total soluble sugars, proline and protein contents were also determined along with the activities of stress enzymes: Catalase, Peroxidase and Superoxide dismutase. The obtained results indicate that inoculation with the indigenous AMF complex has a positive impact on the plant's growth as all the assessed parameters were significantly improved in the mycorrhizal plants. Additionally, our results show that mycorrhization contributes to the minimization of the impact of drought stress on the carob plants and allows a better adaptation to dry conditions.
Background: Plant strategies for adapting to drought could be improved by associations between plant roots and soil microorganisms, including arbuscular mycorrhizal fungi (AMF) and plant growth ...promoting rhizobacteria (PGPR). In this study, the impact of a selected AMF complex and a selected PGPR species on the growth of tomato (Lycopersicum esculentum Mill.) under induced water stress was evaluated.
Methods: Three different inoculation treatments were applied to tomato seedlings (a complex of AMF composed mainly of Glomus genus a Bacillus sp. PGPR treatment and a combination of both) and three different water levels (75%, 50% and 25% of field capacity).
Result: A significant damaging impact of drought on tomato growth parameters and root mycorrhizal colonization, although the presence of microbes stimulated tomato plants growth and decreased the impact ofdrought stress. Indeed inoculated plants presented greater heights, fresh and dry weights, leaves number and area; greater water status; and greater proteins, sugars and chlorophylls contents either with the AMF complex or the Bacillus sp. in normal and drought stress conditions compared to the non-inoculated plants. However dual inoculation recorded the highest values under all water levels treatments.
Le cyprès de l’Atlas, Cupressus atlantica Gaussen, est endémique stricte de l’ouest du Haut Atlas marocain. Cette espèce joue un rôle écologique et socio-économique très important dans son aire de ...distribution : pour produire du bois de feu, aider à protéger les sols contre l’érosion, et comme plante médicinale chez les populations locales. Malheureusement, subissant diverses pressions, principalement le surpâturage et les activités humaines excessives, l’espèce souffre d’une détérioration alarmante et de perte de territoire. La variabilité des champignons mycorhiziens arbusculaires et sa réponse à l’inoculation mycorhizienne des plantules sous serre ont été étudiées pour différentes provenances. Douze populations naturelles représentant l’aire de distribution du cyprès de l’Atlas ont été sondées, à Adebdi, Aghbar, Allous, Idni, Ighil, Ighzer, Mzouzit, Rikt, Tiouna, Taghzout, Talat N’os and Taws. L’analyse des variations des champignons mycorhiziens associés aux racines de cyprès de l’Atlas ont révélé la présence d’au moins sept morphotypes appartenant aux genres Rhizophagus, Glomus, Gigaspora et Acaulospora. Le taux de colonisation mycorhizienne dans les racines du cyprès de l’Atlas a été examiné dans son milieu naturel, montrant une variation de 25 % à 45 %. Dans les conditions sous serre, la croissance des plantules, avec ou sans inoculation avec un complexe mycrohizien, a été surveillée pour les plantules provenant des douze lieux échantillonnés. Les résultats montrent qu’en absence des champignons bénéfiques dans le substrat de culture, la croissance et la nutrition des plantules ont été hautement dépendantes de l’origine des graines. En revanche, en présence du champignon dans le substrat de culture, les paramètres de croissance et de nutrition des plantules des douze provenances ne différaient pas de manière significative. Deux groupes principaux ont été identifiés par l’analyse en composantes principales et la classification ascendante hiérarchique basées sur les caractères analysés. Le premier groupe comprend les populations de la vallée de N’Fis, à savoir Allous, Idni, Ighil, Ighzer, Mzouzit, Rikt, Talat N’os et Taws, alors que le second groupe est composé des populations du côté sud, Aghbar, Adebdi, Taghzout et Tiouna.
This study was undertaken to assess levels of tolerance to summer drought in Medicago sativa genotypes and to comment on their abilities to adapt to Moroccan conditions. Sixteen alfalfa cultivars ...originating from the Mediterranean basin were tested at an experimental station in Morocco, located in the semi-arid bioclimatic area. Trials were conducted over three years and consisted of one continuously irrigated treatment and another irrigated treatment in which summer watering was withheld for 9 weeks. Results showed that summer water stress significantly reduced aboveground biomass in all of the cultivars tested. This reduction ranged between 23.9 and 42.6% compared with fully irrigated treatment. At the end of stress period, mean summer leaf senescence rate was 83.3%, with a significant difference between cultivars. Ground cover, estimated at the end of summer in the third year, decreased dramatically and ranged between 12 and 30.7%, depending on the cultivar. High intrinsic water-use efficiency was associated with a decrease in stomatal conductance rather than an increase in photosynthesis.
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