Effect of Two Arbuscular Mycorrhizal Fungi Species on Root Nodulation and Amounts of Some Elements in Soyabean on Salt Stress Condition

Abstract
Plants are exposed to stressful environmental conditions in the process of growth and development. One of the most important stresses is the salt stress which can limit the plant’s growth and yield. Plants symbiosis with arbuscular mycorrhizal fungi in salt conditions can affect the plant’s yield as well as growth parameters. The plant’s growth in salt stressful conditions might be reduced either through osmotic potential changes due to a reduction in water potential in root environment or through the effect of ions in metabolic processes. The present study aimed to study on effect AM fungi on tolerance of Soyabean against saline stress. In this study, mycorrhizal and nonmycorrhizal plants were treated with 0.1%, 0.2%, 0.3% NaCl solution via irrigate every week. Mycorrhizal treatments were in four levels including: without mycorrhiza, inoculation with Glomus mosseae(M1), inoculation with Glomus intraradices (M2) and inoculation with both of fungi (M3). Experiments were carried out in randomized block design with four replicates in greenhouse condition. Results of statistic analysis showed significant difference in AMF colonization, nodulation, nodule biomass nitrogen, iron and copper concentration any treatments in different salinity levels (P≤0.05). In mycorrhizal plants in most of salinity levels, a significant decrease in fungal sporulation could be observed. Results showed that AMF improved the plant’s growth in salinity stress by increasing uptake of elements, improving nodulation as well as increasing smotic regulators.

Keywords: Soyabean, Salt stress, Mycorrhizal fungies, Nodulation