Phosphate and potassium solubilizing Siccibacter colletis promotes wheat growth, yield, and nutrient uptake

Wheat is one of the staple crops cultivated worldwide and it requires the application of chemical fertilizers for better yield. However, excessive use of these fertilizers can pollute the environment. The aim of this study was to assess the potential of plant growth-promoting rhizobacteria (PGPR) Siccibacter colletis isolated from foothill fields of the Aravalli Hills with different fertilizer levels on wheat growth, yield, and nutrient content. The ability of the isolate to produce IAA, ammonia, ACC deaminase, and HCN and to solubilize potassium and phosphorous makes S. colletis a good candidate for its use as PGPR. S. colletis produced 577.52 ± 0.64 nmol/mg/h and 50.36 ± 3.23 μg/mL ACC deaminase and IAA, respectively, besides solubilizing P (745.56 ± 39.07 mg/L) and K (14.6 ± 0.08 mg/L). The potential of the culture was assessed in vivo using pot and field experiments. Under both recommended and reduced doses of chemical fertilizers, application of S. colletis significantly improved plant biomass, biometric, and physiological parameters in both pot and field conditions. The findings revealed S. colletis as a suitable candidate for improving wheat yield with a reduced fertilizer dose, which can help to reduce cultivation cost and pollution.