Breeding of disease-resistant varieties has been the most effective
and economic way to control this disease but the resistance is
often lost in a few years after cultivars released because of the high
variability of the rice blast fungus. To breed rice varieties with
more durable blast resistance, multiple resistance genes utilizing
both qualitative and quantitative genes must be incorporated into
individual varieties [1,6]. In contrast, traditional selections based
on phenotypic screening need much more time.