Effect of Glomus intraradices fungus on growth, nutrients elements and Nickel uptake in tall fescue under Nickel stress

Fungus-plant associations are of the most important mutually beneficial relationships in the ecosystem which positive effects on growth, physiology and ecology of different plants have been already demonstrated. Biological methods such as employing symbiotic (arbuscular mycorrhizal) fungi to roots of plants are considered as potential effective ways of reducing the stressful effects of soil contaminating heavy metals. This study was aimed to assess the role of arbuscular mycorrhizal fungus Glomus intraradices as a symbiotic microorganisms on chlorophyll and carotenoid content of the shoot, soluble carbohydrate level of the root and the uptake of nutrients (copper, zinc, iron, manganese and phosphorus) in root and shoot of Festuca plants under nickel stress as well as evaluating levels of nickel accumulation in root and shoot, and growth indices including root and shoot dry weight, and the root to shoot ratio. Festuca plants in both infected (M+) and non-infected (M-) forms were cultured under four concentrations of nickel (control, 30, 90 and 180 mg per kg), in sterile soil, for three months. Results showed that the presence of G. intraradices fungus, caused an increase in chlorophyll and carotenoid content, soluble carbohydrate and copper, iron, manganese and phosphorus levels of the root and shoot in M+ Festuca plants compared to the M- plants under nickel stress. However it did not show a positive effect on the zinc levels of the root and shoot. The presence of fungus caused a significant reduce in nickel levels of M+ Festuca plants compared to the M- Festuca plants, and was followed with an increase in root and shoot dry weight, and root to shoot dry weight ratio. It caused an enhancement in the resistance of plants to heavy metal of nickel stress.