Abstract:

In order to obtain plant rhizosphere growth-promoting bacteria （PGPR） for promoting the growth of Angelicasinensis and Notopterygiumincisum， the roots of Angelicasinensis and Notopterygiumincisum were as materials. The strains of fix nitrogen， phosphorus-solubilizing and secreting 3-indoleacetic acid （IAA） were screened and separated by selective medium. And the capacities of fix nitrogen， phosphorus-solubilizing and secreting IAA were determined. The biological taxonomys of screened strains were classified using physiological and biochemical indexes and sequence analysis of 16S rDNA. The results showed that 12 strains with nitrogenase activity were isolated and screened， whose nitrogenase activities ranged from 0.30 to 4.04 nmol C₂H₄·mL^-1·h^-1； 6 strains with inorganic phosphorus-solubilizing were isolated and screened， whose amount of phosphorus-solubilizing was from 290.98 to 420.33 μg·mL^-1；^{and 3 strains with secreting IAA were isolated and screened， whose amount of secreting IAA were from 10.38 to 18.63 μg·mL-1. The results of biological taxonomy indicated that the isolated strains with excellent phosphorus-solubilizing properties belonged to the genus Pseudomonas and Falsirhodobacter，which Pseudomonas was dominant genus. Compared the growth-promoting characteristics of strains， WQP-5 （Pseudomonasgrimontii） isolated from Notopterygiumincisum and MDP-8 （Pseudomonasthivervalensis） isolated from Angelicasinensis with excellent properties were screened， which provided good strains for developing special biological fungus fertilizer for Angelicasinensis and Notopterygiumincisum.}

Key words: Angelicasinensis, Notopterygiumincisum, growth-promoting bacteria, nitrogen fixation, phosphorus solubilization, 3-indole acetic acid （IAA）

摘要：

为获取对当归和羌活生长具有促生作用的促生菌（plant growth promoting rhizobacteria，PGPR），以当归、羌活的根系为研究对象，利用选择性培养基分离具有固氮、溶磷和分泌3-吲哚乙酸（IAA）能力的菌株。通过对菌株的固氮酶活性、溶磷能力及分泌IAA的能力进行测定，筛选出促生性能优良的菌株；进一步通过生理生化指标和16S rDNA序列分析相结合的方法分析优良菌株的分类地位。结果表明，共筛选到12株具有固氮酶活性的菌株，其固氮酶活性为0.30～4.04 nmol C₂H₄·mL^-1·h^-1；6株溶解无机磷的菌株，溶磷量为290.98～420.33 μg·mL^-1；3株产IAA的菌株， IAA分泌量为10.38～18.63 μg·mL^-1。经鉴定，溶磷特性优良的菌株属于假单胞菌属（Pseudomonas）和错玫杆菌属（Falsirhodobacter），假单胞菌属为优势菌属。综合各菌株的促生特性，筛选出2株促生性能优良的菌株：WQP-5（Pseudomonasgrimontii）和MDP-8（Pseudomonasthivervalensis），为开发适用于甘肃道地药材当归与羌活专用生物菌肥提供了优良菌种。

关键词: 当归, 羌活, 促生菌, 固氮, 溶磷, 3-吲哚乙酸