Identification of mutations in target genes are essential for functional analyses of genes.TILLING(Targeting Induced Local Lesions in Genomes),a powerful reverse genetics tool,can be used to screen a series of mutants in a mutagenized population In the last few years,we developed TILLING platforms for tobacco and rice by using EMS-mutagenized populations with 1,051 and 6,600 M2 plants,respectively.Using this platform,we are able to knock out genes efficiently.In tobacco,the mutation density is one in every 70 kb,with 36,000 mutations per plant,while in rice,one in every 351 kb,and 1,000 mutations per plant.On average we were able to obtain 15 and 20 mutants per kb for rice and tobacco,respectively.So far,we had tilled 185 genes in rice,and obtained 2,167 mutants.The rice TILLING platform is now available to international research community(http://www.croptilling.org).