【摘要】 利用¹⁵N稀释法研究小麦接种肺炎克雷伯氏菌（Klebsiella pneumoniae）43菌株的联合固氮作用。在小麦种子萌动后播种于土盆中,用43菌株接种,定苗后每盆施入¹⁵N丰度为30%的标记硫酸铵25mg,培育70d后测定根、茎的干物质重、含氮量和¹⁵N%原子超,并用乙炔还原法测定根系存在的固氮酶活性。结果表明,小麦根系存在固氮有机体,直接为植株提供氮素占其总氮量的15.3—22.1%,干物质重和¹⁵N%含量与对照相比差异显著。更多还原

【Abstract】 The technique of ³⁵N isotope dilution was used to verify that nitrogen was fixed by Klebsiella pneumoniae 43 strain in association with triticum aestivum. Germinated seeds grow siol pots were inoculated with K. pneumoniae 43. （NH₄）₂SO₄ enriched with 30% ¹⁵N was used 25mg/pot. After 10 weeks the shoots and roots were analyzed separately for dry matter, N content, total N, and atom% ¹⁵N excess. The acetylene reduction technique was used to test in the presence of N-fixing organism on the roots. The data of ¹⁵N isotope dilution demonstrated that up to 15.3—22.1% of nitrogen from T. Aestivum were derived from associative N fixation and Klebsiella pneumoniae. The dry matter yield and atom% ¹⁵N excess of wheat significant were increased but were not significant effect on N content and total N inoculated with K. pneumoniae.更多还原