Rhizobacteria in Cyperus iria L.: Elucidating its plant growth-promoting potentials

Abstract

Excessive use of synthetic agents in agricultural production entails negative impacts in the environment. Hence, the search for effective and environment-friendly methods is imperative. This study explored the rhizosphere of Cyperus iria L., a common rice weed, for potential plant growth-promoting rhizobacteria. Fifteen rhizobacterial isolates were tested in vitro for plant growth-promoting characteristics such as phosphate solubilization, ammonia production, catalase production, and antifungal activity. Phosphate solubilization was tested by plating the isolates on Pikovskaya agar while ammonia production was determined via Nessler’s reagent. Catalase production was determined using 3% hydrogen peroxide, while antifungal activity was tested against a plant pathogen, Rhizoctonia solani. Results showed that among the fifteen rhizobacterial isolates, five were phosphate solubilizers while eight showed antifungal activity against R. solani. All isolates tested positive for catalase test and negative for ammonia production. Based on the in vitro screening, the highest phosphate solubilization was observed in Curtobacterium sp. while significant antifungal activity against R. solani was demonstrated by Bacillus sp. It can be concluded that the rhizosphere of C. iria is associated with bacteria that can be further studied to elucidate its plant growth-promoting potential.