Document Type : Research Paper
Authors
1
Ph.D Student, Imam Khomeini International University, Qazvin, Iran
2
Professor. Dept. of Genetic and plant breeding Imam Khomeini International University;Qazvin, Iran
3
Associate Professor. Soil and Water Research Institute Agricultural Research, Education and Extension Organization, Karaj, Iran
4
Assistant Professor. Dept. of medical Zanjan University of Medical Sciences; Zanjan, Iran
5
Professor. Dept. of plant Molecular Genetic National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
Abstract
Pseudomonas bacteria are the most important plant growth promoting rhizobacteria due to their widespread distribution in soil, their potential to colonizemany plant roots and possessing different plant growth promoting characteristics. The present study aimed to identify isolates of Pseudomonas fluorescens strains of olive tree rhizosphere in saline gardens of Qazvin province. Plant growth promoting characteristics of fifteen isolates of Pseudomonas fluorescens strains such as siderophore, auxin, hydrogen cyanide, ACC deaminase enzyme production, phosphorus solubility in liquid medium, pH changes and salt tolerance (NaCl, MgCl2 and CaCl2) (100, 200, 400 mM) were evaluated . Results showed that the dominant strains in producing ACC deaminase were Q7 and Q9, respectively. The Q2 strain was the best one to enhance the production of auxin (11.96 µg.ml-1). The solubility of phosphorus in conjunction with pH showed a negative correlation and the highest amount of dissolved phosphorus was related to Q13 (251) isolate. Also, the half of strains (40%) was not able to produce HCN. Commonly, all studied strains were able to produce siderophore after two, four and six days of incubation. Expect Q1 and Q8, other strains were able to grow in the considered salt concentrations. Based on the results, we concluded that some of these strains can be targeted for genomics studies to improve salt stress resistance in plants and orchards under saline soils conditions.
Keywords