Mycorrhization and root excision effects on morphological and biomass production of carob (Ceratonia siliqua L.)

Ceratonia siliqua L. plant (carob tree) is a Mediterranean species. In Tunisia, natural distribution of this species is situated in humid zones in the north to the driest ones in the south of the country. Ceratonia siliqua regeneration depends on seeds quality and performances as well as on the practical vegetative propagation tools. Nowadays, carob tree cultivation is limited by the seedlings quality behind the juvenile stage caused by the deterioration of plant root system. This study investigates the effect of lone and mutual root excision technique and mycorrhization on carob seedlings growth performance. Two carob seeds origins were germinated then excised and/or mycorrhized using a sterile substate. For control seedlings, experiment was made without excision nor mycorrhization application. Seedlings were grown in green house. Mycorrhizae applied with excision ameliorated significantly plant length, leaf number, dry and fresh weight of external plant part and roots, collar root diameter and roots branching numbers. Survey of mycorrhizae effects proved also amelioration on carob growth and biomass production but indiscernibly than use of mycorrhization and excision techniques together. Excision alone does not take a part on seedling increasing performance. Mycorrhization of carob species applied with excision increased morphological plant status. Results highlighted the efficiency to use this process to promote plants behaviour by enhancing plant roots and growth in forest farming model in forest areas and agricultural lands

Effect of mycorrhization on growth and physiology performance of Quercus species

The development of mycorrhiza could contribute to strengthening the resilience of forest ecosystems to climate change. Several mycorrhizal fungi are known for their valuable effect in increasing plant performances and adaptation to stressful environmental conditions. Thereby, this research aims to investigate how Terfezia boudieri (Chatin) mycorrhizal fungi affects the growth (primary root length, above-ground plant weight) and the physiological behaviour (net photosynthesis, responses to intercellular [CO2] and the intensity of photosyntically active radiation) of Quercus subsp. coccifera  and Q. suber L. Inoculated and non-inoculated seedlings of the two Quercus species were grown in one-liter pots in the greenhouse, with a temperature that ranged from 25 to 30 °C, natural lighting and an irrigation applied twice a week with top water. Results revealed that primary root length and the above-ground biomass increased with mycorrhization. In addition, mycorrhization promoted net photosynthesis (at 400 ppm and at saturation point), the apparent quantum yield, the water use efficiency, and the photosynthetic pigments contents. However, inoculation decreased the light compensation point for both species. Effectiveness of T. boudieri inoculation on Quercus sp. performance, highlights the potential of the mycorrhization process to improve forest management and resilience to climate change

Secondary metabolites of Santolina africana: chemical profiles and assessment of biological activities

Chemicals and antibiotics are serious problems that cause the resistance of bacteria and the persistence of chemical residues in food. These chemical products affect human health and promote diseases. Therefore, the use of natural resources, especially plants, appears as an alternative to avoid the harmful impacts of such products. Plant active substances such as essential oils, alkaloids and phenols are of great interest to scientists and have been studied for their biological activities. Essential oils (Eos) from the stems of Santolina africana were extracted by hydrodistillation and analyzed by Gaz Chromatography/ Mass Spectrometry (GC-MS). The antioxidant activity of crude extracts and Eos was evaluated by the DPPH assay and the antibacterial activity was evaluated by the disc diffusion method and the broth microdilution method against Gram-positive strains (Bacillus subtilis, Staphylococcus aureus) and Gram-negative strains (Escherichia coli, Salmonella paratyphi, and Pseudomonas aeruginosa). S.africana Eos from Morocco and Tunisia were found to be rich in artemisia ketone (35.4% and 44.3%, respectively), santolina alcohol (16.2%and 3.2%, respectively) and isoborneol (6.1% and 26.6%, respectively). Methanol extracts were rich in phenolic and flavonoids contents and showed the highest DPPH radical scavenging activity. Results exhibited the sensitivity of the strains to essential oils from S. africana especially against Gram-positive bacteria. This current research will provide new information about this plant that can be used as a natural antioxidant and antibacterial for industrial purposes

Growth, root colonization and nutrient status of Helianthemum sessiliflorum Desf. inoculated with a desert truffle Terfezia boudieri Chatin

AbstractThis study aims to investigate the effects of inoculation using Terfezia boudieri Chatin ascospores (ectomycorrhizal fungus) on growth, root colonization and nutrient status of Helianthemum sessiliflorum Desf. seedlings grown in pots on two-soil types (gypseous and sandy loam). Mycorrhizal seedlings had significantly increased their height and leaf number compared to non-mycorrhizal ones. Regardless of mycorrhizal inoculation treatments, the plants growing on gypseous soil showed higher growth as compared to sandy loam one. It appears that inoculation with T. boudieri changed root morphology, increasing branching of first-order lateral roots of H. sessiliflorum seedlings. The highest root mycorrhizal colonization was recorded in inoculated seedlings on sandy loam soil (89%) when compared to gypseous one (52%). N, P and K concentrations in mycorrhizal seedlings were significantly improved by fungal inoculation. It can be concluded that inoculation of H. sessiliflorum with T. boudieri increased growth attributes and improved plant nutritional status