Phylogenetic relationships betweenVicia faba (Fabaceae) and related species inferred from chloroplasttrnL sequences

The chloroplast trnL intron from 46 different Vicia accessions, representing five of the nine sections of the genus Vicia subg. Vicia sensu MAXTED (1991a) were amplified by the Polymerase Chain Reaction (PCR) using oligonucleotide primers homologous to conserved regions in trnL. The products fell into two distinct groups; those of approximately 250 nt and those of around 450 nt in length. Of these, products from 17 different Vicia species were cloned and their nucleotide sequences determined. Multiple alignments were assembled and phylogenetic trees constructed by the weighted least-squares distance method. A Lathyrus latifolius trnL intron sequence was used as an outgroup. The resulting trees clearly group and separate the sectt. Narbonensis, Bithynica and Faba species but were less able to distinguish species from sectt. Hypechusa and Peregrinae. Based on these sequence data, V. faba appears to be more distant from sect. Narbonensis than sectt. Hypechusa and Peregrinae. The results are in general agreement with a recent treatment of Vicia subg. Vicia (MAXTED 1993) and lend further support to placing V. faba in the monospecific sect. Faba.