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本文报道在福建部分地区及盆栽中采集的800多个根样包括97个水稻品种的固氮酶活性检测结果及根系固氮微生物的分离。通过测定发现水稻根系具有固氮酶活性是较为普遍的,采用切根加培养基预培养后,其根内固氮酶活性出现率可达70～90％以上。水稻根系具有固氮酶活性的样品的分布,与水稻品种、植株生育期、种植地区以及土壤环境有关,固氮酶活性较高的根样大多出现在省肥耐瘦株型紧凑的品种,纬度较低、气候温暖的闽南地区,处于孕穗—灌浆的生育期以及盐碱土、坑田的土壤环境。几年来从有固氮酶活性的根系中分离到菌株1,317个,其中表现固氮酶活性的473株,占分离总数的36％。并发现这些分离的固氮茵的生长和固氮需要含有少量有机氮(如酵母膏)的培养基,对氧分压的要求因菌株不同而异。还检到一些真菌具有乙炔还原活性。
This paper reports the detection of nitrogenase activity in more than 800 root samples collected from parts of Fujian and potted plants, including 97 rice cultivars, and the isolation of nitrogen fixing microorganisms in the roots. It was found that the nitrogenase activity in rice roots was relatively high. After preincubation with cut root plus medium, the rate of nitrogenase activity in roots reached 70 ~ 90%. The distribution of samples with nitrogenase activity in rice roots was closely related to the rice varieties, plant growth period, planting area and soil environment. Most of the root samples with high nitrogenase activity appeared in the compact variety with low fertilizer-tolerance rate and low latitude , The warm southern Fujian region, in the booting - grouting growth period, and saline soil, pit soil environment. In recent years, 1,317 strains of bacteria have been isolated from the root system with nitrogenase activity, of which 473 strains exhibit nitrogenase activity, accounting for 36% of the total number of isolates. And found that the growth and nitrogen fixation of these isolated Azotobacter cultures required medium containing small amounts of organic nitrogen (such as yeast extract). The oxygen partial pressure requirement varies by strain. Some fungi were also found to have acetylene reduction activity.