Abstract
Amplified fragment length polymorphisms (AFLP) were utilized to examine systematic relationships in Lathyrus L. sect. Lathyrus (Fabaceae). In addition to a parsimony-based phylogenetic tree, AFLP-based trees were constructed using Dice, Jaccard, and mean character difference coefficients to produce distance-based trees using the UPGMA and neighbor-joining methods. All trees clearly show a close relationship among accessions of the same species, confirming the monophyly of the species examined. All analyses indicate that species of the section Lathyrus are distinct from species of other sections. These findings confirm the monophyly of the section and contradict proposals to split it. They do not support the segregation of L. gorgoni in the section Gorgonia. Within the section Lathyrus, several relationships are present but are only weakly supported. The use of AFLP data to resolve systematic relationships in the genus Lathyrus is further demonstrated.