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