Abstract

The aim of this work was to evaluate the effects of different vegetable oil formulations on the temperature tolerance and storage duration of Beauveria bassiana conidia. The germination ability of conidia mixed with eight vegetable oils including rapeseed, soy, sesame, corn, coconut, grape, olive and almond oils, were evaluated for the conidia temperature tolerance at 25, 30, 35, 40 and 45°C by spreading conidia over Sabouraud dextrose agar (SDA). The germination ability of conidia mixed with eight vegetable oils was evaluated after 1, 2 and 3 week storage at 25°C by spreading over SDA. Results show that there was significant difference between tolerance of conidia to different vegetable oils formulation so that the highest and the lowest germinations were established for variants with Sesame and Olive oils formulation respectively. The highest germination was proved at25°C. The germination ability was reduced gradually by increasing the storage duration so that the percent germination reduction were 33, 44 and 52 for first, second and third week of conidia storage, respectively. The Sesame and Olive oils formulation had the highest and the lowest effects on conidial storage respectively.

Key words: Vegetable oils, Beauveria bassiana, temperature tolerance.