Effect of Some Liquid and Solid Media on Sporulation of Beauveria bassiana

An identification of optimal environmental conditions and effective factors for growth and sporulation of biological control agents is indispensable for their mass production. In this study, the effect of some liquid and solid media were evaluted for Beauveria bassiana sporulation. The results of experiments on B. bassiana indicated that in liquid media the effect of light (p=0.0001), food quality (p=0.0001) and interaction between light and food quality (p=0.0027) was significant on blastospore production with potato extract leading to a highest production of blastospores. Although dry weight of blastospores was significantly affected by light (p= 0.0006) and food quality (p=0.0001), yet the interaction between light and food quality (p=0.1547) was not significant on dry weight of blastospores. The results also demonstrated the role of time on the rate of daily blastospore production (p=0.0001). Blastospore production increased rapidly during the first three days after inoculation, then the rate was reduced. The use of different liquid media for blastospore production showed that sporulation in liquid media was significantly (p=0.0004) affected by food quality. Potato and millet extracts had the highest and lowest rate of sporulation, respectively. The results of the experiments demonstrated that fungus activity changed the pH of media toward acidic. The results also demonstrated that in solid media the effect of food quality was significant (p=0.0086), cereal with superabsorbent leading to the highest sporulation. Also, in other experiments, results of use of millet (as a solid medium for sporulation) showed that the effect of food quality and its various treatments on sporulation was significant (p=0.0001), maximum sporulation occuring on boiled seeds.