高寒地区燕麦根际联合固氮菌研究 Ⅱ固氮菌的溶磷性和分泌植物生长素特性测定

Associative nitrogen-fixing bacteria in the rhizosphere of Avena sativa in an alpine region Ⅱ Phosphate-solubilizing power and auxin production

对分离自高寒地区燕麦根际的8株联合固氮菌株溶磷性和分泌植物生长素特性进行了测定,结果表明,菌株Azotobactersp.ChO4、Azotobactersp.ChO5和AzospirilluslipoferumChO6具有溶磷能力,但溶磷强度差异较大(83.8～103.5μg/mL),AzospirilluslipoferumChO6溶磷能力较Azotobactersp.ChO5和Azotobactersp.ChO4强;8株菌株均具有分泌植物生长素特性,但能力差异较大(2.16～17.31μg/mL),只有Pseudomonassp.ChO3和AzospirilluslipoferumChO6分泌IAA的浓度较高(大于10μg/mL)。研究认为,菌株Pseudomonassp.ChO3、Azo-tobactersp.ChO4、Azotobactersp.ChO5、AzospirilluslipoferumChO6和AzospirillusbrasilenseChO8等在燕麦菌肥研制方面具有较大的开发潜力。

The phosphate solubilizing power and auxin (IAA) production of eight associative nitrogen-fixing bacteria (ANB) isolated from the oat rhizosphere in Tianzhu, Gansu province, northwest China, an alpine region, were determined. Three strains showed phosphate-solubilizing power, namely, Azotobacter sp. ChO4, Azotobacter sp. ChO5 and Azospirillus lipoferum ChO6, but the difference in ability was large (83.8-103.5 (μg/mL).) The phosphate-solubilizing power of Azospirillus lipoferum ChO6 was greater than the other two strains. All the strains showed ability to produce auxin (IAA) although the difference in ability was large (IAA concentration was 2.16-17.31 μg/mL). Only two strains, Pseudomonas sp. ChO3 and Azospirillus lipoferum ChO6, excreted high IAA concentrations (greater than 10 μg/mL). From the view of phosphate-solubilizing power and IAA production, it is considered that strains including Pseudomonas sp. ChO3, Azotobacter sp. ChO4, Azotobacter sp. ChO5, Azospirillus lipoferum ChO6 and Azospirillus brasilense ChO8 have relatively larger potential as inoculants in oat biofertilizer.