Genetic linkage map of Mercedes4.11, homology groups 1 to 4. Mercedes4.11 is the female parent of a F1 mapping population in tetraploid alfalfa. Each box contains the homologous chromosomes of one group. The groups were numbered similarly to M. truncatula (T. Huguet, unpublished data) and diploid M. sativa (G. Kiss, pers. comm.). The chromosomes within each group were arbitrarily numbered from 1 to 4 and are orientated as in M. truncatula. When JoinMap software split the map of one chromosome in 2 or 3, each linkage group was named by the number followed by a letter. The number to the left of the chromosomes refers to the genetic distances (Kosambi cM) from the top. The number to the right of the chromosomes refers to the marker names. The SSR markers are in upper-case and the AFLPs in lower-case letters. AFLP markers followed by "d" had a distorted segregation. When several SSR loci came from a single primer pair, their names were composed of the name of the primer pair followed by a number.