In vitro antifungal activity of chitinolytic enzymes produced by bio-agents against root rot pathogenic fungi

Abstract

A study was carried out using simple laboratory techniques to examine the influence of the antagonistic isolates of Trichoderma harzianum, T. viride, Bacillius subtilis and Pseudomons flourescence and their culture filtrates on selected soil-borne root rot pathogens Rhizoctonia solani and Fusarium solani. Testing procedures were standardised using two different methods. The experiments were based on the principle of dual culture and agar diffusion techniques. The experiment involved the recording of the percentage of reduction in growth and inhibition zones formed by various filtrates of antagonistic culture growth. The results showed that the antagonists tested had the ability to reduce the linear growth of fungal pathogens. Also, the cultures filtrates of antagonists had antifungal activities by forming inhibition zones. Culture filtrates have shown a strong clear inhibition zone which increases in diameter as the incubation period of antagonists increases. This observation was related to the increase in the activity of chitinolytic enzymes as secondary metabolic compounds produced in growth media by prolonging the period of incubation. The study has proved that such enzymes can be effectively used for suppression of soil-borne pathogens and that it can evolve as a potential biocide.

Keywords:

• chitinolytic enzymes
• Bacillus subtilis
• Fusarium solani
• root rot
• Rhizoctonia solani, Trichoderma harzianum
• Trichoderma viride