Thermotolerant mutants of entomopathogenic fungi obtained by ion beam- and ray-induced mutagenesis

Saito, Tsutomu*; Fitriana, Y.*; Sato, Katsuya; Ono, Yutaka; Narumi, Issey*

Entomopathogenic fungi, such as , are economically important agents for integrated pest management programmes of insect pests. However, negative effects of temperature, such as heat stress that exceeds 35 C, can have serious deleterious effects on conidial germination and persistence, vegetative growth, sporulation, and/or the infection process in these entomopathogenic fungi. In this study, we attempted to enhance thermotolerance in a model entomopathogenic fungus, , by mutagenesis using ion beams or rays and evaluated the relative virulence of the resulting mutants compared with the wild-type isolates. In conclusion, ion beams and rays are useful tools for improving biological characteristics, such as thermotolerance and fungicide-tolerance, in entomopathogenic fungi, but the mutants obtained in this study must be carefully evaluated for unpredictable negative side effects.