自从Yoshida等(1971)发现水稻根系具有固氮酶活性(乙炔—乙烯)和Stewer(1974)提出结合性共生固氮的概念以来,水稻结合性共生固氮的研究引起了广泛的注意。人们企图通过筛选和回接高效的结合性共生固氮菌株,以改善水稻的氮素营养,提高谷物产量。据报道,至今至少从水稻根系中分离到4种结合性固氮细菌,它们分别是:固氮螺菌(Azospirillum lipoferum和Azospirillum brasilenees);肠杆菌(如Enterobacter Since Yoshida et al. (1971) found that the root system of rice has nitrogenase activity (acetylene-ethylene) and Stewer (1974) proposed the concept of associative nitrogen fixation, the study of rice-associated symbiotic nitrogen fixation has attracted a great deal of attention. It is attempted to improve the nitrogen production and improve the grain yield of rice by screening and reconnecting efficient symbiotic nitrogen-fixing strains. It has been reported that up to now, at least four kinds of binding nitrogen-fixing bacteria have been isolated from rice roots, namely Azospirillum lipoferum and Azospirillum brasilenees, Enterobacter species such as Enterobacter