Author(s): Yang Jiebin
Pages: 87-94
Year: 1983 Issue:  4
Journal: Journal of China Agricultural University
Keyword:  巴西固氮螺菌; 联合固氮微生物; 禾本科作物; 生物固氮; 固氮酶活性; 接种试验; 固氮细菌; 菌株; 分离; 培养基;
Abstract: Azospirillum strains are nitrogen-fixing bacteria which associate with the root of grasses in life. Beijerinck(1923)first isolated and described this bacterium as Azo- tobacter spirillum and later(1925)renamed it as Spirillum lipoferum. Its nitrogen-fixing property was definitely confirmed by Becking(1963) with~(15)N technique.Recently,Tarrand,Krieg and D(?)bereiner proposed a new genus Azospirillum.The genus Azospirillum can be divided into two species:A.lipoferom and A.brasilense.The results of inoculation experiments were different among various experiments studied in dif- ferent regions,some being positive(subba Rao 1980;Cohen 1980),and some having no effect on crop production(Albrecht 1981).We consider that the difference may be caused by the level of soil fertility beca- use nitrogenous compounds contained in soil inhibit the ability of the nitrogen fixation. As Azospirillum strains are closely associated with the root system of cereal crops,they differ from the freeliving nitrogen-fixing bacteria and can obtain its carbon and energy sources from the root secretion easily. Since 1979 we have isolated some strains from the root of maize and sorghum in Beijing and we are now working on the selection of NH_4-resistant strains. This paper is a review of Azospirillum including its discovery hi- story,morphology,physiology,taxonomy and the problems of agricu- ltural application.