**7.2.1 TILLING approach**

In the TILLING approach, the polymorphisms (more specifically point mutations) resulting from induced mutations in a target gene can be identified by heteroduplex analysis (Till *et al*. 2003). This technique represents a means to determine the extent of variation in mutations artificially induced. EcoTilling represents a means to determine the extent of natural variation in selected genes in the primary and secondary crop gene pools (Comai and Henikoff, 2006 and Kumar *et al.* 2010). Like TILLING, it also relies on the enzymatic cleavage of heteroduplexed DNA, formed due to single nucleotide mismatch in sequence between reference and test genotype, with a single strand specific nuclease under specific conditions followed by detection through Li-Cor genotypers. At point mutations, there will be a cleavage by the nuclease to produce two cleaved products whose sizes will be equal to the size of full length product. The presence, type and location of point mutation or SNP will be confirmed by sequencing the amplicon from the test genotype that carry the mutation.
