The essential oils yield of Cedrus atlantica, Chenopodium ambrosioides and Eucalyptus camaldulensis was different. C. ambrosioides gave a relatively higher yield (2.1 ± 0.1%), while that of C. atlantica was low (1.0 ± 0.1%) and that of E. camaldulensis was lower (0.75 ± 0.1% of dry matter). The active ingredients of the essential oils and some of their biological effects were also determined. The characterization of their chemical compositions showed that the three essences have different chemical profiles: C. atlantica was richer in sesquiterpenes (β-Himachalene (54.21%) and γ -Himachalene (15.54%)), C. ambrosioides was very rich in monoterpene peroxides and monoterpenes (α-Terpinene (53.4%), ascaridole (17.7%) and ρ-Cymene (12.1%)) and E. camaldulensis was very rich in monoterpene compounds and monoterpenols (p-cymene (35.11%), γ-Eudesmol (11.9%), L-linalool (11.51%) and piperitone (10.28%)). The in vitro measurement of antioxidant activity by the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) reduction assay showed a significant performance of the eucalyptus oil and average performance of the other two (C. atlantica and C. ambrosioides). The in vitro bio-test for their antimicrobial effects showed that the antibacterial activity differed depending on the essential oil and the concentration used, and that their bactericidal efficacy was similar or superior to that of synthetic antibiotics. The toxicity test on rats revealed that the LD50 of the three essential oils was 500 mg/kg body weight, which classifies them as category four cytotoxic natural products at high doses.

Our objective is to test selected mycorrhizal complexes to verify the contribution of mycorrhizal symbiosis as a biological tool promoting the development of the argan tree under hostile conditions. In addition, this study aims to assess the impact of soil drought caused by stopping watering of young argan plants inoculated with strains of fungal complexes indigenous to the species in comparison to non-inoculated plants. Under conditions of water deficit stress, the most marked reductions in fresh and dry biomass were recorded in non-mycorrhizal plants. The most negative values of leaf water potential Ψf and Ψb were also noted in non-mycorrhizal plants. On the other hand, plants inoculated with mycorrhizal Bouyzakarne inoculum were relatively less affected by watering discontinuation compared to those inoculated with mycorrhizal Argana inoculum. Water stress caused a reduction in potassium and phosphorus content in the leaves and roots of all plants. However, mycorrhizal plants exhibited the highest P and K values compared to non-mycorrhizal ones. Therefore, mycorrhization compensates for the deficit in absorption of inorganic nutrients during drought. Sodium gradually decreased in the leaves but increased in the roots, and this delocalization of Na+ ions under water deficit stress resulted in higher concentrations in the roots than in the leaves of all plants. However, the mycorrhizal plants exhibited relatively lower values of root Na+ compared to the non-mycorrhizal controls. The water deficit reduced the content of chlorophyll a and b in the leaves and the chlorophyll a/b ratio in stressed plants. The lowest chlorophyll values were recorded in non-mycorrhizal plants. The levels of proline and soluble sugars in the leaves and roots of argan plants increased in all plants, especially with the extension of the duration of stress. However, proline accumulation was higher in mycorrhizal plants, with superiority in plants inoculated with the Bouyzakarne complex in comparison with that of Argana. In contrast, the accumulation of soluble sugars was higher in non-mycorrhizal plants than in mycorrhizal plants. We concluded that with a correct choice of the symbiotic fungi complexes, AMF inoculation biotechnology can benefit argan cultivation, especially under stressful conditions in arid regions with structural drought, where native Arbuscular mycorrhizal fungi levels are low.

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The aim of this study was to evaluate the membrane integrity and some physiological responses of rootstock citrus calli under exposure to different concentrations of NaCl. Selected salt-tolerant cell lines were compared with salt-sensitive calli of Troyer’s citrange (Citrus sinensis [L.] x Citrus trifoliata [L.] Raf.) (TC) with respect to growth, water content, Na+, K+ and Cl− ion content as well as cell membrane stability under exposure to different NaCl concentrations. The results show that the stressed sensitive lines have a consistently high ion efflux. The values recorded for these sensitive calli are 3 to 6 times higher than those of the tolerant calli. Thus, only selected halotolerant calli were able to maintain the integrity of their membranes under salt stress conditions. In the sensitive calli, NaCl always induces a slowing down of growth even from 4 g L−1, and the reduction in the relative growth rate is higher than 50% and reaches more than 90% for the three culture durations at 8 g L−1 NaCl. For the salt-tolerant selected lines, the relative growth rate seems to be slightly slowed down until the second month of culture but becomes equal to that of the control at the third month, whether at 4 or 8 g L−1 NaCl. At the end of the third month, the relative growth rate of the selected calli is 100% at 8 g L−1 NaCl. The water content is twice as high in the selected tolerant calli as in the sensitive ones after three months of salt treatment at 8 g L−1 NaCl. After long-term culture, the halotolerant calli absorbed similar or even higher amounts of Na+ and Cl− than the salt-sensitive lines. However, by the 3rd month, the recorded accumulation rate dropped in the unselected but continued to increase in the tolerant calli (4-fold higher at 12 g L−1 NaCl than the control). Furthermore, exposure of both types of calli (salt-sensitive and salt-tolerant) to equal concentrations of NaCl resulted in greater loss of K+ by the NaCl-sensitive lines. However, for tolerant lines, K+ uptake is not affected at 4 g L−1 NaCl and the decrease in tissue content is less than 25% at 8 g L−1 NaCl. From this observation, it can be concluded that growth and the ability to retain high levels of internal K+ are correlated.