What are RILs?
The acronym RIL stands for Recombinant Inbred Line. These are produced to form a permanent and stable QTL mapping resource. In the first step of the development of RILs, two parental inbred lines are crossed (mated) together to form a uniformly heterozygous F1 generation. The F1 are intermated (or selfed) to form an F2 generation; most individuals in the F2 will contain recombinant chromosomes resulting from crossovers between the two purely parental chromosomes present in each F1 plant. The parental alleles are said to be segregating in the F2 generation, since it is a matter of chance just which of the three combinations of parental alleles (A/A, A/B, or B/B) will occur in a given F2 plant. Numerous individuals from the segregating F2 generation then serve as the founders of corresponding RILs. Each subsequent generation of a given RIL is formed by selfing in the previous generation and with single seed descent. In this manner each RIL, after several generations, will contain two ide
