The effect of Hydrogen Peroxide on the viability of Beauveria bassiana and their ability for radial growth on Chitin Agar

Abstract

This study aimed to evaluate the effects of five concentrations of hydrogen peroxide (50, 100,200,300,400) ppm on the viability of Beauveria bassiana spores after 1,2,3,4 days of exposure at 28 ± 1C° and on the radial growth ability of the fungus on chitin agar medium after 11 days of incubation at 26 ± 1C°.This fungus was also used to control the Date palm dubas Ommatissus lybicus. The results showed that the viability of B. bassiana spores of control (distill water with fungal spores) of a rate ranged between 157 – 257 colony/ petri dish on potato dextrose agar and the rate 257 colony/petri dish was higher than those of other treatments, while the rate 91.7 colony/petri dish at 50ppm concentration of hydrogen peroxide was the best p= 0.05 in comparison with the viability rate of other treatments in which the spores were exposed to highest concentrations of hydrogen peroxide. It was also seen that spores lost their viability after exposure to 400 ppm of hydrogen peroxide. On the other hand, the results showed that the rate of radial growth 3.46cm in control group after 4 days of incubation in comparison with this in the other group was higher. The fungus showed lowest rate of radial growth 0.43cm after one day of incubation p= 0.05, while the one day exposure of spores to each of 50,100 ppm of hydrogen peroxide showed 3.47,3.5cm respectively which were significantly higher p= 0.05 in comparison with other concentrations, improving which the higher concentration the lower activity of fungal degrade chitin.