Journal of Pure and Applied MicrobiologyVol. 9 No. Special Edition May. 2015

Screening and Characterization of Plant Growth-Promoting Bacteria in the Rhizo- and Endosphere of the Cucumber

S. Rafiei1 and GH. Khodakaramian1

Department of Plant Protection, College of Agricultural, Bu-Ali Sina University, Hamedan, Iran.

Received on 06 January 2015 and accepted on 12 Feburary 2015

 

ABSTRACT

Plant growth promoting bacteria (PGPB) are beneficial bacteria that can improve the extent or quality of plant growth via wide variety of mechanisms.To look for efficient PGPB strains having multiple activities, total eight bacterial isolates were isolated from rhizosphere and endosphere of cucumber in Iran. Eight isolates of PGPB designated as Pseudomonas protegens strain BASU390, Acinetobacter calcoaceticus strain BASU624, Brevibacillus formosus strain BASU625, Paenibacillus peoriae strain BASU645, Arthrobacter phenanthrenivorans strain BASU589, Pseudomonas protegens strain BASU 630, Pseudomonas putida strain BASU 205 and Stenotrophomonas pavanii strain BASU553 were successfully isolated and characterized through phenotypical traits and 16S rDNA gene sequencing.The bacterial isolates were subjected for different plant growth promotion activities. Subsequently, to investigate the effects of the bacterial isolates on the growth of cucumber a pot culture experiment was conducted.All of the isolates demonstrated remarkable plant growth promotion activities. Furthermore, most of isolates resulted in a significant increase in plant height, root length, and dry matter production of shoot and root of cucumber seedlings. Therefore, present study suggests that PGPB isolates viz. BASU390, BASU625, BASU645, BASU589, BASU630 and BASU205 may be used as biofertilizers to enhance the growth and productivity of cucumber.

Keywords : Plant growth promoting bacteria, Phosphate solubilization, HCN, IAA