16. Development and characterization of rice mutants for functional genomic studies and breeding

Mutagenesis is a powerful tool for creating genetic materials for studying functional genomics, breeding, and understanding molecular basis of disease resistance. Approximately 100,000 putative mutants of rice (Oryza sativa L.) have been generated with mutagens. Numerous mutant genes are involved in plant architecture, grain quality and disease resistance have been isolated and characterized. Numerous rice cultivars with high yields and superior grain quality have been developed and effectively deployed for rice production worldwide. In this chapter, we describe (1) detailed methods of ethyl methanesulfonate, irradiation and fast neutrons for creating useful rice mutants; (2) methods for analysis of rice genes that are responsible for mutations; (3) utilization of these new mutants for rice breeding and functional genomics; and (4) molecular mechanisms of blast resistance gene-mediated defence responses.