土壤产气肠杆菌的解磷特性及其对毛竹苗的促生作用

目的 探究土壤中具有解磷功能的产气肠杆菌的解磷特性及其对毛竹的促生效果。 方法 采用液体震荡培养法评价不同碳源、氮源和环境因子对产气肠杆菌解磷能力的影响，并采用温室盆栽法研究该菌株对毛竹根际土壤有效养分和酶活性、根系和叶全磷及叶磷组分含量的影响，并分析其对毛竹的促生作用。 结果 产气肠杆菌分别在碳源为蔗糖或葡萄糖、氮源为硫酸铵、初始pH值5.5～6.5、装液量1/5或2/5、盐离子浓度为0或1.0 g·L−1时溶解Ca2(PO4)3的能力最强；产气肠杆菌对Ca2(PO4)3和CaHPO4两种难溶性磷源的平均解磷量分别达331.83 mg·L−1和345.91 mg·L−1。与对照相比，施用产气肠杆菌处理毛竹根际土壤有效磷含量、磷酸酶活性、脲酶活性、叶片净光合速率分别增加50.9%、20.6%、21.0%和42.0%；毛竹实生苗地径、苗高和生物量分别提高31.0%、23.5%和44.5%。施用产气肠杆菌处理显著提高毛竹根系全磷和叶片核酸磷含量，显著降低叶片残留磷含量，但叶片全磷、无机磷和糖磷无显著变化。 结论 该产气肠杆菌具有对环境适应性较强的潜力，可助益提高根系磷吸收和叶片核酸磷积累而促进毛竹生长，是南方丘陵缺磷区竹林生物专用肥料研制的潜在菌株，具有较好的应用前景。

Phosphate Solubilizing Characteristics of Enterobacter aerogenes and Its Growth-promoting Effect on Phyllostachys edulis Seedlings

Object This study aims to investigate the phosphate-solubilizing characteristics of Enterobacter aerogenes and its growth-promoting effect on Phyllostachys edulis. Methods The effects of different carbon sources, nitrogen sources, and environmental factors on phosphate solubilizing ability of E. aerogenes were evaluated by culture method of shaking liquid. The effects of the strain on available nutrients, enzyme activities, total phosphorus contents of roots and leaves, and phosphorus fractions of leaves in rhizosphere soil of P. edulis were studied using pot experiment in greenhouse. Results E. aerogenes displayed the strongest phosphate-dissolving capacity on tricalcium phosphate when the initial pH was 5.5～6.5, the volume of liquid was 1/5 or 2/5, and salt ion concentration was 0 or 1.0 g·L−1. Carbon source was sucrose or glucose, and nitrogen source was ammonium sulfate. The average phosphate solubilization of E. aerogenes to Ca2(PO4)3 and CaHPO4 was 331.83 mg·L−1 and 345.91 mg·L−1, respectively. Compared with the control treatment, the rhizosphere soil available phosphorus, phosphatase, urease activities and leaf net photosynthetic rate increased by 50.9%, 20.6%, 21.0% and 42.0% in P. edulis seedlings inoculated with E. aerogenes. The ground diameter, seedling height, and biomass accumulation were higher by 31.0%, 23.5% and 44.5%, respectively. Total phosphorus contents of roots and nucleic acid phosphorus contents of leaves in P. edulis significantly increased while residual phosphorus contents in leaves significantly decreased. Total phosphorus, metabolic phosphorus, and sugar phosphorus contents in leaves were steady due to inoculating E. aerogenes. Conclusion E. aerogenes has potential to highly adapt to the environment and improves the growth of P. edulis seedlings via increasing root phosphorus absorption and leaf nucleic acid phosphorus accumulation. It is also a potential strain for the development of special biological fertilizer for bamboo forest in phosphorus deficient area of Southern hills and has a good application prospect.