Improvement of common bean growth by co-inoculation with Rhizobium and plant growth-promoting bacteria

In the greenhouse experiment, two Bacillus and two Pseudomonas strains were examined for their ability to promote common bean growth (Phaseolus vulgaris L) when co-inoculated with Rhizobium phaseoli. Co-inoculation with Rhizobium and Pseudomonas sp. LG or Bacillus sp. Bx Unproved shoot dry weight, nitrogen and phosphorus contents in bean plants, compared to inoculation with Rhizobium alone. Pseudomonas sp. LG promoted bean growth and particularly P uptake more efficiently than Bacillus sp. Bx. In vitro screening for plant growth-promoting traits showed phosphate solubilization, IAA, ammonia and siderophore production by Pseudomonas sp. LG, as opposed to Bacillus sp. Bx, which showed only ammonia production. Multiple plant growth-promoting traits of Pseudomonas sp. LG may be associated with its ability to improve common bean growth and nutrient uptake efficiently.