Potential of Biological Nitrogen Fixation and Micro-nutrients Absorbed by some strains of Rhizobium bacteria coexist in Beans in two Regions of Isfahan Province

Most inoculation studies have focused on free-living diazotrophs, although a few reports indicate rhizobia can act as PGPR. In order to evaluate nitrogen fixation ability of different strain of Rhizobium legominosarum biovar phaseoli in common bean, a randomized complete block design including 6 rhizobial isolates(L-100, L 41, L-75, L-216, L-54 and L-139 selected from different provinces by soil & water research institute), one nitrogen fertilizer (400 kg Urea per ha) and one control plot (without seeds inoculated and fertilizer) in four replication was carried out in two field (Dehaghan & Esfarjan) at Isfahan province in 2003. Results showed that significant differences were observed in seed and dry matter yield, total nitrogen absorption, number and weight of nodules and seed yield among seed inoculated with different strains and non-inoculated controls. In Dehaghan field, seed inoculation with L-75 strain and in Esfarjan field, seed inoculation with L-54 and L-139 strains increased dry matter yield, total nitrogen absorption, number and weight of nodules and seed yield. Results also showed that seed inoculation with some rhisobia isolates increased micronutrients absorption. In Dehaghan field, inoculation of L-216 and L-75 strains led to higher absorption of Cu and Zn. Some isolates could not promote nitrogen absorbtion.