Plant growth promotion properties of bacterial strains isolated from the rhizosphere of the Jerusalem artichoke ( Helianthus tuberosus

The Jerusalem artichoke (JA; Helianthus tuberosus), known to be tolerant to salt-alkaline soil conditions, has been cultivated for many years in the Yellow River delta, Shandong Province coastal zone, in China. The aim of our study was to isolate nitrogen-fixing bacteria colonizing the rhizosphere of JA and characterize other plant growth promotion properties. The ultimate goal was to identify isolates that could be used as inoculant benefiting an economic crop, in particular for improving wheat growth production in the Yellow River delta. Bacterial strains were isolated from the rhizosphere soil of the JA on the basis of growth on nitrogen-free Ashby medium. Identification and phylogenetic analysis was performed after nucleotide sequencing of 16S rRNA gene. Plant growth-promoting (PGP) traits such as nitrogen fixation activity, phosphate solubilization activity, indole-3-acetic acid (IAA) production was determined using conventional methods. Eleven strains were isolated and six of them were further examined for their level of salt tolerance and their effect on plant growth promotion. Inoculation of Enterobacter spp. strain N10, on JA and wheat, led to significant increase in both dry weight root and shoot height. Enterobacter spp. N10 appeared as the best PGP rhizobacteria to increase wheat productivity in future field applications.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author