Molecular characterization and classification of Stylosanthes mexicana, S. macrocarpa, S. seabrana and S. fruticosa by DNA sequence analysis of two chloroplast regions.

The trnL (UAA) intron and trnL (UAA) - trnF (GAA) intergenic spacer region from the diploid species Stylosanthes mexicana, S. macrocarpa and S. seabrana and the tetraploid species S. fruticosa were amplified by polymerase chain reaction and subjected to direct DNA sequencing. Comparison of these chloroplast regions with previously determined DNA sequences of 19 Stylosanthes species revealed a close relationship with a clade containing the diploid species S. hamata, S. calcicola, and the tetraploid species S. scabra. The results were used to infer relationships between the diploid species of this clade, in relation to the alloploid species S. scabra and S. fruticosa.