高寒草甸植物根际溶磷菌的筛选鉴定及其溶磷与促生效果

为获得高寒草甸根际土中优良溶磷菌资源，本研究从青海省高寒草甸根际土中筛选了4株溶磷菌，结合16S rRNA基因分析法确定其分类地位，并通过钼锑抗比色法和盆栽试验进行了溶磷与促生效果的研究。结果显示：4株溶磷菌均为假单胞菌属(Pseudomonas sp.)，均可形成明显的溶磷圈。在无机磷液体培养基中培养7d后，4株菌株的磷增量在156.17~511.33μg·mL^-1之间；溶磷过程中4株菌均分泌多种有机酸，总有机酸量在522.36~986.69mg·L^-1之间；盆栽试验表明4株菌均能显著增加披碱草(Elymus dahuricus Turcz.)株高和地上部干重；菌株MXSC5，MXSC6和MQC13可使植株全氮、全磷含量增加，且4株菌株对土壤速效氮、速效磷含量也有正向影响。本研究结果将有助于进一步探究溶磷菌对植物的促生作用及微生物菌肥的开发利用。

Screening and Identification of Phosphate-Solubilizing Bacteria in Plant Rhizosphere of Alpine Meadow and Their Effects on Phosphate-Solubilizing and Plant Growth Promotion

In order to obtain the excellent phosphate-solubilizing bacteria resources in the rhizosphere soil of the alpine meadow,four phosphate-solubilizing bacteria were screened from the rhizosphere soil of an alpine meadow in Qinghai province and identified by 16S rRNA gene analysis. Through the anti-molybdenum antimony colorimetry and pot experiment the effects of dissolving phosphorus and promoting growth were studied. The results showed that the four strains were Pseudomonas. They all could form prominent phosphate solubilizing circles. When cultured in inorganic phosphate liquid medium for 7 days,the phosphorus the four strains released was 156.17~511.33 μg·mL^-1. Various organic acids were secreted by the four strains during phosphate solubilization,and the total organic acid amount ranged from 522.36 to 986.69 mg·L^-1. Pot experiments showed that four strains could significantly increase the plant height and aboveground dry weight of Elymus dahuricus,and promote the growth of Elymus dahuricus. Strains MXSC5,MXSC6 and MQC13 could increase the contents of total N and total P in plants,and the four strains also all had a positive effect on available N and available P content of soil. The results help to investigate further the role of phosphorus-solubilizing bacteria in the promotion of plant growth and the development and utilization of microbial fertilizers.