Abstract
Vicia faba L.-rhizobia symbiosis is utilized in different biological ways to improve the productivity of faba beans. This research aims to analyze the effects of the Rhizobium strain on nodulation, N-2 fixation, growth and ion accumulation under salt stress in Vicia faba. The commercial cultivar of faba beans (Vicia faba L. var. minor) was inoculated with the Rhizobium leguminosarumbiovar, by considering viciae strains S10 and S16, after 15 days of growth. This inoculation was carried out in the solution culture consisting of two salt concentrations; 0 mmole l(-1) NaCl and 50 mmole l(-1) NaCl. The results revealed that under saline and non-saline conditions, S10 and S16 strains of Rhizobium leguminosarum resulted in the formation of ineffective and effective symbiosis with faba beans. However, the presence of salt stress resulted in increasing the biomass of nodule and nitrogen content. The concentrations of sodium and chloride, in shoot and root, were increased in the presence of salinity. However, potassium concentration was only increased in the shoot. With and without salinity, phosphorus concentration in the shoots was not modified. The results revealed that the salt tolerance of faba beans, inoculated with two strains of Rhizobium were found to possess association with their stable growth. Moreover, the salt tolerance of faba beans inoculated with two salts tolerant rhizobia was also associated with an increment in the capacity of faba beans to increase nodulation and the concentration of shoot N-2, Na and Cl- content. In addition, salt tolerance of this variety, inoculated with Rhizobium strains was associated with a decrement in the concentration of K+ in shoot under the salt constraints.