high-energy ion beam irradiation has been used to induce
mutations in many plant species [7–12]. Recently, low-energy
ion implantation has been explored as a new method to produce
new genetic modifications in crops and microbes. Such low-energy
ion beam bombardment has provided many advantages including
a low damage rate, a high mutation rate, a wide mutation spectrum
and cost effectiveness [13,14]. In Thailand, low-energy ion beam
modified Thai jasmine rice (KDML 105) has resulted in many
new lines with characters of higher yields, photoperiod
insensitivity and semi dwarfism [15]. In a new development in
combating the blast disease, ion beam biotechnology continued
to play its important role in inducing blast disease resistant
mutants of local rice. In this work, the blast resistant rice mutants
were obtained from ion-bombarded Thai jasmine KDML 105 rice
and characterized for phenotype and their genotype change. Also
the genes involved in the blast disease resistance were characterized
and the expression patterns in the rice mutant tissues were
investigated.