水稻根际高效解磷细菌SP1的筛选及其促生作用研究

Screening of Highly Efficient Phosphate-Solubilizing Bacterial Strain SP1 from Rice Rhizosphere and Its Potential for Plant Growth Promotion

摘要: 以北方寒地种植的水稻、玉米和大豆根际土壤为试材，采用含Ca₃(PO₄)₂的NBRIP培养基筛选解无机磷细菌，并通过形态观察、生理生化特征分析及分子生物学方法对其进行鉴定。利用钼蓝比色法测定菌株的解磷能力，结合盆栽试验探究菌株对水稻的促生长作用及根际土壤改良效果，旨在为寒冷地区生物磷肥的开发提供优良菌种。结果显示，菌株SP1被鉴定为泛菌属革兰氏阴性短杆菌，在NBRIP培养液中可溶性磷含量最高达900.31 mg/L；盆栽试验结果显示，接种菌株SP1后，水稻生长显著促进、产量明显提高，同时根际提高水稻根际土壤的有效磷含量，降低土壤的pH值。研究表明，泛菌SP1是一株兼具高效解磷能力与促生长特性的细菌，可应用于生物磷肥开发及土壤改良。

Abstract: The rhizosphere soils of rice, maize and soybeans from the cold regions in northern China were used as experimental materials. To provide excellent strains suitable for the development of bio-phosphate fertilizer in cold region, the inorganic phosphate-solubilizing bacterium was screened by NBRIP medium containing Ca₃(PO4)₂, and then was identified based on morphology, physiology and biochemistry, and molecular biological methods. Its phosphate-solubilizing activity was determined by molybdenum blue colorimetry method, as well as the effects of bacterium inoculation on rice growth-promoting and rhizosphere soil improvement were investigated by the pot experiments. The results showed that the strain SP1 was identified as a member of Pantoea sp., rod-shaped Gram-negative bacterium. The soluble phosphorus content of strain SP1 in the NBRIP broth reached 900.31 mg/L. The growth and yield of rice were significantly promoted by inoculation of strain SP1 in pot experiments. Meanwhile, the pH value of rice rhizosphere soil was reduced. Research results indicate that the Pantoea SP1 strain is a growth-promoting and efficient phosphorus-solubilizing bacterium, which could be applied for the development of biological phosphorus fertilizer and soil improvement.