Abstract
Plant growth-promoting rhizobacteria (PGPR) and endophytes form symbiotic associations with plants and improve growth through several mechanisms In the present study, phosphate (P) solubilizing PGPR and endophytic bacteria (EB) were isolated from wheat roots and screened for plant growth-promoting features. Most of the P solubilizing isolates were capable of solubilizing zinc along with production of exopolysaccharides (EPS) and siderophores. A total of seven isolates from endophytic bacteria (EB) (ZE1, ZE5, ZE7, ZE15, ZE19, ZE32 and ZE,38) and eight isolates from rhizosphere bacteria (ZR2, ZR3, ZR5, ZR7, ZR15, ZR18, ZR19 and ZR25) were chosen to evaluate their plant growth promoting prospective under axenic conditions. Results revealed that the maximum root colonization, and improvement in seedling vigor index (69%), root length (31%), shoot length (29%), root dry biomass (33%) and shoot dry biomass (36%) as compared to uninoculated control was found by co-inoculation of ZE32 and ZR19 followed by the combination ZE15 + ZR2, and ZE15 + ZR3. Strains from these best performing combinations were identified as Bacillus subtilis ZE15, B. megaterium ZE32, B. subtilis ZR2, B. subtilis ZR3 and B. megaterium ZR19 through 16S rRNA partial gene sequencing. These strains possess multiple plant growth promoting characteristics and can be recommended as potential bioinoculants for biofertilizer after extensive evaluation under field conditions. (C) 2020 Friends Science Publishers