Isolation and characterization of plant growth promoting rhizobacteria from rhizospheric soil of selected pulses and their effect on Coriandrum sativum plants

Abstract

Plant growth-promoting bacteria (PGPB) are recognized as efficient biofertilizers, biocontrol agents and microbial inoculants. In the present study five best plant growth-promoting rhizobacteria were isolated from the root zone of healthy and vigorously growing plants in an agricultural farm in the Uttaradit Province, Thailand. All the isolates were selected on the basis of nitrogen fixation, indole-3-acetic acid (IAA) production and phosphate solubilization. Based on morphological traits and 16S rRNA sequence analysis, isolated bacteria were distributed into the following six genera: Burkholderia cepacian (A05, A06), Agrobacterium deltaense (A13), Pseudomonas plecoglossicida (A39), Paenarthrobacter aurescens (A45) and Stenotrophomonas pavanii (A64). All the selected bacterial isolates boosted coriander growth. Paenarthrobacter aurescens (A45) showed the best results, it increased plant height (up to 1.38 times), dry weight (up to 1.63 times), stem diameter (up to 2.05 times) and biomass (up to 1.65 times). This is the first report of plant growth-promoting ability of Paenarthrobacter aurescens, which could be used as a biological agent instead of chemical fertilizers in agroforestry production to reduce environmental pollution and increase the yield of coriander.