Dry seeds of Arabidopsis thaliana were irradiated with F ions and H ions with the energy range from keV to MeV

respectively. The inhibition of germination was investigated to display the influences of ion mass

energy and fluence. The results show that H ion irradiation is more effective in decreasing the germination rate than heavier F ion irradiation. After irradiation of F ions

a decrease-increase-decease type of germination rate-fluence response curve was found and the ion fluence at the peak position decreases with ion energy increase. The possible mechanism of above experimental results is discussed in this paper.