SPOROGENESIS OF THE ENTOMOPATHOGENIC FUNGUS VERTICILLIUM-LECANII IN SOLID-STATE CULTURES

The entomopathogenic fungus Verticillium lecanii was cultivated in different solid-state cultures using wheat bran, sugar-beet pulp, and mixtures of both. The optimum value of water activity for growth and sporogenesis was 0.990-0.995. The use of water for medium moistening was more efficient in supporting spore formation than the use of dilute Czapek-Dox mineral medium. The yield of spores (per 1 g of the medium dry matter) was 3.0 x 10(9), 1.6 x 10(9), and 3.2 x 10(9) in the wheat bran medium, sugar-beet medium, and mixed medium, respectively. Conidial germination in soil extract (80 x dilution) was independent of the spore origin and was about 43 %.