They were developed by backcrosses from triploid F1 hybrids with genomic constitution LmLmFp, (where Lm and Fp are used to denote the genomes of L. multiflorum and F. pratensis, respectively) to tetraploid L. multiflorum cv. ‘Mitos’. From the backcross of single chromosome substitutions to tetraploid L. multiflorum, we have developed series of recombinant lines with with various lengths of Festuca chromatin present for each chromosome (about 30 recombinant lines per chromosome).