The Effect of Heavy-Ion Beams with High Linear Energy Transfer on Mutant Production in M₁ Generation of Torenia fournieri

抄録

A high-LET heavy-ion beam has a severe effect on survival and effectively induces chromosomal rearrangements. In this study, the effect of high-LET heavy-ion irradiation on mutation induction in the M₁ generation was investigated in an inbred line of Torenia fournieri, which is a widely used horticultural plant. Dry seeds of the inbred line ‘Zairai murasaki’ were irradiated with a C-ion beam (LET: 50 keV µm⁻¹) or Ar-ion beams (LETs: 184 keV µm⁻¹ or 290 keV µm⁻¹) at different doses, and then sown on 1/2 MS plates. After determining the survival rates from each irradiation condition, appropriate doses of each beam were roughly determined to produce a survival rate of 90%: 300, 75, and 50 Gy for the C-ion beam with a LET of 50 keV µm⁻¹, Ar-ion beam with a LET of 184 keV µm⁻¹, and Ar-ion beam with a LET of 290 keV µm⁻¹, respectively. In the screening of branches with aberrant flowers, one and two aberrant plants were isolated from 16 and 30 M₁ plants after irradiation with LETs of 184 keV µm⁻¹ and 290 keV µm⁻¹, respectively. However, no aberrant plants were identified in M₁ plants after irradiation with a LET of 50 keV µm⁻¹. We concluded that high-LET heavy-ion beam irradiation is effective in inducing mutations even in the M₁ generation of inbred ornamental plants. This technique could be widely used for breeding ornamental plants that can be propagated vegetatively.