Effect of Sinorhizobium sp. isolates on growth, nodulation, and nitrogen fixation of fenugreek

There are thousands of different species of legume plants. They are useful as human and animal food throughout the world. These plants can fix nitrogen on their own through a symbiotic relationship with the soil bacteria known as 'rhizobia'. Application of effective rhizobial strains to improve the crop production is an appropriateapproach in sustainable agriculture. In this study, twenty infective isolates of Sinorhizobiumisolated from nodules of fenugreek (Trigonella foenum-graecum L.). The results indicated that 25% of those strains wereefficient, 30% relatively efficient and 45% non-effective.Then,the most effective isolates (SR4, SR5, SR12 and SR16) selected for a greenhouse experiment.According to the results, all of the selected isolatesincreased shoot (76-110%) and root (17-82%) dry weightof fenugreek significantly. In addition, uptake of nitrogen, phosphorous, iron, manganese, zinc and coppersignificantly improvedby inoculation of fenugreek with Sinorhizobiumisolates.