Background: Two species of ginger were used in Thai traditional medicine as Zingiber officinale Roscoe and Zingiber ligulatum Roxb.
Objective: To investigate for identification two types of ginger by morphological and microscopic characters, DNA profiles, and determination of 6-gingerol content by HPLC.
Material and method: Fresh rhizomes of two gingers, their ages more than one year were collected from 12 sources in 4 parts of Thailand. The fresh leaves were also collected for studying DNA profile by amplified fragment length polymorphism (AFLP) method.
Results: The morphological characters of two types of gingers were almost corresponded to AFLP patterns and they were identified as Z officinale Rocs. and Z. ligulatum Roxb. Microscopic examinations of dried rhizomes from the both species showed the same pattern. By means of HPLC and TLC methods, 6-gingerol content was found only in Z. officanale in range of 2.58-17.04% but disappeared in Z. ligulatum.
Conclusion: Determination of 6-gingerol content by HPLC or TLC pattern can be used to identified two types of ginger used in Thai Traditional Medicine.