Abstract

Parwat Wijarat, Vichien Keeratinijakal, Theerayut Toojinda, Apichart Vanavichit and Somvong Tragoonrung

“Fha-Tha-Laai-Joan” (Andrographis paniculata (Burm. f.) Nees) is a medicinal plant that is, widely used in Thailand and some other countries for therapeutic value, but the lack of their genetic information may cause confusion in its utilization. The randomly amplified polymorphic DNA (RAPD) markers were used to identify and elucidate the phylogenetic relationships among 58 accessions of A. paniculata which were collected throughout Thailand. Of thirty random primers tested, only eight primers generated a total of 66 bands, of which 26 bands were polymorphic, with an average of 8.25 bands per primer pair. The phylogenetic tree derived from RAPD data showed that A. paniculata were divided into only one group in which the high similarity values were between 0.81-1.00. The results obtained indicated that the distributions of A. paniculata among each region are likely to belong to the same variety and are relatively undifferentiated across a large geographic range. The floral architecture and reproductive habitat study of A. paniculata revealed the same results as of RAPD markers analysis. This species is thus hermaphroditic and acts as habitual inbreeder.