Peeled seeds of a local rice species (Oryza sativa L. cv. KDML
105) were placed in sample holders (Fig. 1). The rice seeds were
positioned such that their embryonic ends were directly exposed
to the incident ion beam. Then the sample holders were put inside
the target chamber of an ion implanter. The ion implanter was
modified from a machine traditionally for industrial applications
in surface modification (Fig. 1A). It was featured with high beam