غلام خداکرمیان

Nitrogen is one of th e most important nutrients in plants which its shortage in soil is the limiti ng factor of plant growth. Nitro gen molecular gas comprises about 80 % of the atmospheri c gases whereas it is not directly used by plants. The rhizobia are a large and diverse group of soil bacteria th at are capable of root nodule formation and ni trogen fi xation and ex.i st in symbiosis with leguminous plants. To identifi cation of Rhizobium strains inciti.ng nodules on roots of chickpea (Cicer arietinum L.) , 60 strai ns were isolated from nodules and soil around roots in East Azarb aij an and Hamedan provinces. The strains were identified by comparing their biochemical , physiological and profi.l es of the cell proteins characteri stics with references strains of Mesorhizobium mediterraneum USDA 3392 and M.ciceri USDA 3383. AU strai ns prod uced 950 and 750 bp fragments of nodC and nifH genes in PCR reactions usin g nod CF/nodCI and nifHf/nitHI primers, respecti vely. From 40 strai ns, 22, 10 and 8 strains were identified as M. mediterrraneum, M.ciceri and Mesorhizobium sp., respectively.