Published online by Cambridge University Press: 27 March 2009
The studies were designed for breeding resistant varieties of rice to bacterial leaf blightcaused by Xanlhomonas oryzae (Uyeda et Ishiyama) Dowson with induced mutations. In 1971, seedlings of irradiated lines (X$) originated from treatments of 60Co γ-and X-radiation and control (C6), which were propagated in bulk up to X6(C6) generations after the treatments, were inoculated with highly virulent isolates.
The results showed that the variability of disease reaction within the irradiated lines increased in both resistant and susceptible directions from the control mean. It was assumed from these results that the irradiation treatments could induce polygenic mutations to give both germ types more resistant and those more susceptible to bacterial leaf blight, suggesting that such treatments might be an effective approach for breeding varieties resistant to the disease.