Species diversity, usages, molecular markers and barcode of medicinal Senna species (Fabaceae, Caesalpinioideae) in Thailand

The diversity of the Senna species found in Thailand and usages was investigated. Species identification was performed using morphological characters concurrently with DNA fragment sizes of the trnH-psbA spacer region. The fourteen Senna species in Thailand are Senna alata, Senna alexandrina, Senna fruticosa, Senna garrettiana, Senna hirsuta, Senna occidentalis, Senna pallida, Senna siamea, Senna sophera, Senna spectabilis, Senna sulfurea, Senna surattensis, Senna timoriensis, and Senna tora. Usage information in Thailand was recorded by observation, viewing, market surveys, literature reviews, and interviews with locals and traditional healers. Most of these species are widely used as foods, ornamentation, and medicine for Thai people. Using of primers from the trnH-psbA spacer region as barcode primer, the different DNA fragment sizes of the trnH-psbA spacer region were taken for a species-specific marker for further rapid, accurate and automatable species identification for a plant part namely leaf, chopped plant or powdered. Moreover, the DNA fragments were sequenced for the basis of barcode as nucleotide differences among species. These tag sequences have been submitted to the GenBank data base, with the accession numbers.