Development of thermotolerant mutants of entomopathogenic fungi using ion beam irradiation

Fitriana, Y.*; Sato, Katsuya; Narumi, Issei; Tagami, Yosuke*; Saito, Tsutomu*

Thermotolerant mutants of entomopathogenic fungi, , and , were screened from conidia irradiated with carbon ion beams at doses ranged from 100 to 1000 Gy. Sabouraud dextrose broth (SDB) and Sabouraud dextrose agar (SDA) were used for the screening. The wild-type strain of the three fungal species formed colonies with abnormal shape on SDA at 33C. For , 41 isolates that could normally grow in SDB at 35C were successfully obtained, and finally 5 isolates were selected as potential mutants that will be used for further studies. Any normal colonies could not be obtained from SDA at 35C. The results show that ion beam irradiation is useful to generate thermotolerant mutants of entomopathogenic fungi. However, thermotolerant mutants of and have not been obtained yet.