Genetic Diversity of Curcuma in Thailand using External Transcribed Spacer (ETS) Sequences

The Curcuma is the largest genus of Zingiberaceae whi ch has been widely used as an important medicinal plants, spices and cosmetics. Consequently, genetic diversity from 22 samples of Curcuma was analyzed using the 5′ region of the external transcribed spacer (ETS) of 1 8S–26S nuclear ribosomal DNA sequences. The DNA sequ ences varied in length from 579-583bp. Neighbor-Joining (NJ) with Kimura -2-parameter was used to reconstruct phylogenetic trees. The genetic distance among sampl es ranged from 0.003-0.134. Curcuma was monophyleti c ntities based on ETS analyses. The phylogenetic tree showed t hat 22 samples of Curcuma could be separated into 2 groups with high bootstrap support. The most genetic simil ar ty was found between C. aeruginosa and Curcuma s p. 1 which is consistent with the geographical distribution. The h ig bootstrap support (97%) indicated that Curcuma sp. 5, Curcuma sp. 6, Curcuma sp. 7, C. amada 1, C. amada 2, C. amada 3 and C. amada 4 were closely related s pecies. This study represented the potential of ETS as a good ca ndidate region for phylogenetic analysis of Curcuma species.