Effects of ion beam irradiation on the regeneration and morphology of Ficus thunbergii Maxim

Abstract

Shoot explants cut from aseptically grown Ficus thunbergii plants were irradiated with ¹²C⁵⁺, ¹²C⁶⁺ and ⁴He²⁺ ion beams of 10 to 200 Gray (Gy). After irradiation, the explants were allowed to regenerate. The regeneration frequency (RF), or percent explants bearing regenerated shoots to the total number of explants irradiated, decreased in a dose-dependent manner. Morphological changes in leaves and stems were observed in regenerants. The morphological change frequency (MF), or percent regenerants bearing morphologically changed shoots to the total number of regenerants peaked at 15 to 25% at the dose of each ion beam that gave an RF of about 80% (except for ⁴He²⁺). A negative correlation was observed between the linear energy transfer (LET) and ion beam dose both in RF and MF. The present results strongly suggest that ion beam irradiation can induce mutations in the genome of F. thunbergii.