UPASANA SAHU, RICHA VAISHNAV, RENU, S. R. MOHANTY, SWATI MOHAPATRA, AJIT VARMA AND SWATI TRIPATHI*
Amity Institute of Microbial Technology, Amity University, Noida-201 313 (Uttar Pradesh), India
*(e-mail: swatitri@gmail.com; stripathi2@amity.edu; Mobile: 77479 58222)
(Received: April 1, 2023; Accepted: May 8, 2023)
ABSTRACT
Sustainable organic farming to fulfil the requirements of food for the growing population across the globe
as well as the growing concerns of impact of chemical fertilizers and climate change need to be addressed using Plant Growth Promoting Rhizobacteria (PGPR) to maintain soil health and enhance crop productivity.
Rhizospheric soil was collected from the upland rice field of Raigarh village in Pusaur dist. Raipur, Chhattisgarh. A total of 146 isolates obtained were screened qualitatively and quantitatively for plant growth promoting (PGP) activities like phosphate, potassium and zinc solubilization, IAA production, siderophore production, ammonia production and nitrate reduction. The isolates were further subjected to biochemical and molecular characterization for the identification of potential PGPRs. Ninty three out of 146 isolates, were found positive in both qualitative and quantitative PGP characteristics. The range of insoluble phosphate solubilization varied from 19 to 60 µg/ml. Siderophore production of bacterial isolates
ranged from 12 to 31% and the IAA ranged from 10 to 54 µg/ml. The potential isolates RIGA-65, RIGB-93, RIGB-130 and RIGB-146 were proved to be efficient in seed germination and pot experiments. Among four isolates, Bacillus subtilis strain (RIGA-65) was found to be the most potent PGPR with maximum insoluble phosphate solubilization (60 µg/ml), siderophore production (31%) and IAA production (54 µg/ml). The highest germination was also recorded in Bacillus subtilis strain RIGA-65 (97%) followed by RIGB-93 (83%), RIGB-130 (81%) and RIGB-146 (22%) as compared to the untreated control (22%).
Key words : Rhizosphere, PGPR, phosphate solubilization, potassium solubilization, IAA production, siderophore production