Generation of Rice Mutants by Chemical Mutagenesis

Chemical mutagenesis of rice has been used extensively to generate useful genetic variation for the purpose of breeding improved varieties. More recently, advances in high-throughput genotyping platforms have enabled the efficient detection of point mutations generated by chemical agents. This in turn has renewed interest in using traditional chemical mutagenesis to generate mutant populations for gene discovery and functional characterization. Targeting of Induced Local Lesions in Genomes (TILLING) is a powerful reverse genetics method which combines chemical mutagenesis with the high-throughput discovery of point mutations. Numerous chemical mutagens have been shown to be effective in generating point mutations and small deletions in rice. This chapter describes the use of a combination of sodium azide (NaN₃ ) and N-nitroso-N-methylurea to generate populations that are suitable for TILLING as well as forward genetics and mutation breeding.