Chemically and physically induced mutagenesis in basidiospores of oyster mushroom Pleurotus ostreatus var. florida

The oyster mushroom Pleurotus ostreatus is the third important edible mushroom in the world, following the button and shiitake mushrooms. There is an increasing interest to utilize mutation in order to obtain desirable characteristics in edible mushrooms, including P. ostreatus. However, there is a scientific shortage of information available on accurate experimental details of mutation induction in P. ostreatus, particularly while it comes to basidiospores. Therefore, the objective of this study was to obtain a reliable method to induce physical and chemical mutations in P. ostreatus var. florida basidiospores through ultraviolet (UV) irradiation and ethyl methane sulphonate (EMS). The findings revealed that the UV exposure at a distance of 45 cm for 120 seconds and the EMS treatment at 1.5% caused a maximum killing effect (over 95%) in the basidiospores, as compared to the untreated spores. Moreover, the 50% lethality dose (LD50) was seen to be at 41.73±2.5 seconds of the U.V exposure and the concentration 0.51±0.05 % (v/v) of EMS. The findings of this study warrant further research to investigate morphological and developmental characteristics in fruiting bodies generated by the putative mutant spores. In addition, the experimental conditions established in this study may be useful for inducing mutation through UV radiation or EMS treatment in basidiospores of P. ostreatus.