The Legume–Rhizobia Symbiosis

摘要: The symbiotic nitrogen fixation (SNF) with legumes is the primary source of biologically fixed for agricultural system. It performed by a group bacteria commonly called rhizobia. characterized host preference, and differences among symbioses between rhizobial strains legume genotypes are related to infection, nodule development effectiveness in N2 fixation. interaction rhizobia mediated lipochitin oligosaccharide secreted rhizobia, “Nod factor”. recognized transmembrane receptors on root-hair cells legume. can regulate organogenesis inducing changes cytokinin balance root, during initiation. nodules catalyzed nitrogenase enzyme depending upon photosynthate supply, O2 concentration, fixed-N export. Among environmental factors that influence SNF, temperature essential formation; salinity drought decrease permeability supply nodule, phosphorus deficiency inhibits total Rhizobia differ their efficiency There evidence genotypic variability SNF at different levels available P which show possibility selecting cultivars able support biological under low soils.