Effects of mycorrhizal fungi on morphological and physiological parameters of Sorghum (Sorghum bicolor L.) under Chrome stress

This study aimed to evaluate the effects of four levels of mycorrhizal fungi (0، 50، 100، 150 g) and chrome levels (0، 5، 10، 15 mg/l) as a heavy metal on sorghum physiological and morphological characteristics. A factorial experiment was carried out in a completely randomized design with four replications in greenhouse condition. The results showed that the effects of arbuscular mycorrhizal fungi had significant effect on root length، root dry weight، plant height and plant fresh weight. Results indicated that the presence of the fungus lead to a reduction in negative effects of chrome toxicity. With increasing chromium concentration، plant heights in plant species inoculated with mycorrhizal fungus (50 and 100 grams treatments) were increased. The chrome toxicity was decreased in high level of fungus treatments. Mycorrhizal plant had high chlorophyll content when they exposed to various level of chrome. The results showed that there were no significant differences (p ≤0/01) in amount of soluble sugars in the shoot of sorghum plants inoculated with the fungus and the plants exposed to chrome stress. The results showed that the toxicity of the chelators such as Guaiacol peroxidase enzyme activity، Ascorbate peroxidase and Catalase mycorrhizal and non-mycorrhizal plants also were increased. The findings of this study suggest that Arbuscular mycorrhizal fungi can facilitate sorghum growth in soils polluted by chrome.