Effect of temperature and pH on growth and sporulation of both Local isolates of biological control fungi Metarhizium anisopliae and Beauveria bassiana

Abstract

A laboratory study was conducted by using two local isolates of biological control fungi M. anisopliae and B.bassiana that isolated from the soil of citrus orchards that infested with Mediterranean fruit fly Capitata ceratiris  in Baghdad to know  the effect  of four different temperatures included 15, 20, 25 and 30 ° C and four levels of  the pH, including 5, 6, 7 and 8 on  the growth and sporulation of  two local isolates on liquid medium. Results showed that the highest growth of the fungus M. anisopliae was at  20° C, average dry weight was1.19 gm and best sporulation of the fungus at 25°C ,it was 10.3×10⁴ spore/g, while was higher growth and sporulation for B. bassiana at 20 °C , they were 1.11 gm and 2.7 × 10⁴ spore / g, respectively, the results showed that the highest dry weight for M. anisopliae and B.bassiana was at /pH 7,they were 5.9 and 3.38 gm respectively, and the best sporulation for them when the pH5  ,they were 3.9×10⁴ and 3.8×10⁴ spore /g respectively, the isolated fungus B. bassiana surpass in the production of both chitinase and proteinase enzymes depending on decomposition aureole diameter, they were 15.76 and 11.37 cm, respectively, compared to M.anisopliae which amounted 14.17 and 4.36 cm respectively.