Page 51 - Abstract book - TJSSF-2020

Thailand – Japan Student Science Fair 2020 (TJ-SSF 2020)
“Seeding Innovations through Fostering Thailand – Japan Youth Friendship”

Development of Molecular Markers to Identify Thai Herbs at
Species Level Authentication

Kornvarun Tirananmongkol , Atsuki Matsuzawa , Mingkwan Rattanasiwamok
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Advisors: Supanan Sucharit , Pimpen Tiansittipong
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Mahidol Wittayanusorn School
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Abstract
Using appropriate species of herbs is essential for producing effective herb products because some
active ingredients can be found only in specific species. But identifying species by morphological
characteristics requires expertise and can be confusing. We decided to find a more precise way to
identify herb species by analyzing DNA sequences to find species specific sites. In this study, we chose
4 species of herb which are Stevia rebaudiana, Carthamus tinctorius, Mentha spicata and Gynostemma
pentaphyllum as our species of interest. We extracted DNA from plant tissues (leaves), performed PCR
amplification of ITS2 region, sequenced the PCR product, and analyzed the sequence by comparing
with closely related species in the same genus. For the result, we found 7 to 9 sites in
S. rebaudiana, C. tinctorius and M. spicata that have 70% or higher specificity. But in contrast, in
G. pentaphyllum we only found 3 sites with specificity of 65.22%. We concluded that ITS2 region can
be used to specify S. rebaudiana, C. tinctorius and M. spicata, but might not be suitable for specifying
G. pentaphyllum.

Keywords: DNA sequences analyzing, Molecular marker, ITS2 region, Thai herb

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