草地早熟禾根际固氮菌的生物效能

利用乙炔还原法、比色法等对草地早熟禾(Poa pratensis)根际分离得到的21个固氮菌株进行固氮酶活性、溶磷能力和分泌植物生长素性能的研究测定，在固氮酶活性测定中，21个菌株还原C2H2产生的C2H4在39.9～227.5 nmol·mL-1·h-1，大于100 nmol·mL-1·h-1的有14株，占所分离固氮菌株的67%;菌株的溶磷强度在13.38～58.21 μg·mL-1，其中菌株N4 、N16及N20溶磷能力较强;菌株N2、N4、N5、N10、N14、N16、N17及N20具有较强的分泌植物生长激素的能力。

Biolonisal efficiency of nitrogen fixation strains isolated from rhizosphere of Poa pratensis

Both acetylene reduction and colorimetric methods were employed to measure nitrogenase activity,the solubilizing phosphorus capability and secretion of plant growth hormone of 21 nitrogen-fixing bacteria strains isolated from Kentucky bluegrass rhizosphere soil samples.The result indicated that the nitrogenase activity of 21 tested nitrogen-fixing bacteria strains were between 39.9 and 227.5 nmol·mL-1·h-1.There were 14 strains (67% of all strains) whose activities were more than 100 nmol·mL-1·h-1.The solubilizing phosphorus intensity of nitrogen-fixing bacteria were between 13.38 μg·mL-1 and 58.21 μg·mL-1.Three of these tested strains-N4,N16 and N20 demonstrated stronger solubilizing phosphorus capability.Eight of these tested strains——N2,N4,N5,N10,N14,N16,N17 and N20 demonstrated strong ability of excreting plant growth hormone were measured.