Effects of Inoculation with Mycorrhizal Fungi on Growth and Heavy Metals Concentrations in Two Wheat Cultivars under Salt Stress Condition

The soil salinity and the diffusion of potentially toxic chemicals to the soil environment through industrial and agricultural activities are known as important factors affecting the productivity of crop plants. Thus, an efficient strategy to increase crop yield, and to improve human and environmental health, is necessary to mitigate the impacts of these detrimental factors. Accordingly, a factorial pot experiment using a randomized complete block design was conducted to investigate the effects of symbiosis with mycorrhizal fungi on the growth and heavy element absorption rate in two bread wheat cultivars (Roshan and Bahar) grown under salinity stress within a soil contaminated with heavy metals. The treatments consisted of irrigation water salinity at three levels (0, 75 and 150 mM NaCl) and plant inoculation at three levels (no-inoculation, inoculation with Funneliformis mosseae and Rhizophagus intraradices mycorrhizal fungi). Salinity stress reduced shoot and root dry weights but increased the concentration of cadmium, lead and zinc in the shoot and root tissues of both tested cultivars. The increase in Cd concentration and the decrease in shoot dry weight was significantly lower in Roshan (salt tolerant) than in Bahar (salt sensitive) cultivar. Under both none-saline and saline conditions, the shoot and root weights of both studied cultivars were increased in the plants inoculated with F. mosseae and Rh. intraradices compared to none-inoculated plants but the increases were greater in Roshan than in Bahar. Moreover, mycorrhizal inoculation decreased the concentration of cadmium and lead in shoot. However, the extent of these decreases were dependent on fungal species, salinity level and the used cultivar. The results of this experiment showed that while salinity decreased plant growth and increased heavy metal accumulation, mycorrhizal inoculation improved plant growth and decreased the concentration of these elements in wheat plants.