Characterization of Paenibacillus polymixa N179 as a robust and multifunctional biocontrol agent

摘要

The strain N179 was isolated from agricultural fields and selected through screening, based on its antagonistic potential, PGPR activity and robust biofilm formation. This strain was identified as Paenibacillus polymyxa based on morphological, biochemical and molecular characteristics. It was found that this strain has strong antagonistic activity against a wide variety of plant pathogens including fungi, bacteria, Phytophthora drechsleri, and root-knot nematode. The strain N179 was able to produce PGPR-related metabolites and it was able to solubilize mineral phosphate in vitro condition. Results showed that strain N179 is able to promote growth of bean, cucumber, wheat and corn seedlings in growth chamber condition. We also checked the effect of this strain on wheat yield in field condition. Highest yield was achieved when the bacterium was applied by seed coating method with 4 x 10(6) cells/ml concentration. Detached pear blossom and immature pear fruit assays were used to check the ability of N179 to suppress a phytopathogen in vivo condition. In both bioassays strain N179 was able to drastically suppress Erwinia amylovora. Inoculation of turnip cabbage roots with strain N179 resulted in reduction of growth rate of Xanthomonas campestris pv. campestris strain 8004 in leaves and developed symptoms were lower in these plants in comparison to infected control plants.