Novel bacterial endophytes isolated from winter wheat plants as biocontrol agent against stripe rust of wheat

Two strains (JD204 and JC186) were obtained from 127 bacterial endophytes isolated from winter wheat plants, and identified as Pseudomonas putida based on their 16S rRNA and rpoD gene sequences. Both strains produced indoleacetic acid (IAA), with the abilities to solubilize inorganic and organic phosphorus, and to promote wheat growth. Strain JD204 had stronger growth-promoting, phosphorus-solubilizing and IAA-producing activities than strain JC186. Natural infection of stripe rust on the JD204-inoculated winter wheat cultivars was investigated. Disease incidence and disease index were significantly reduced on seven and eight out of 11 JD204-treated wheat cultivars, respectively, compared to their respective controls. Yields were significantly enhanced on eight out of 11 wheat cultivars treated by the strain compared to the controls. The results indicated that strain JD204 could be considered a promising biocontrol agent against stripe rust as well as a yield-enhancing agent for ecofriendly wheat production.