Samples of Zingiber cassumunar Roxb.
were collected by the National Center for
Agricultural Biotechnology from rhizomes of
native varieties of plai: S1 from Sa Kaco province,
S2 from Chiang Mai province and S3 from
Prachuap Khiri Khan province. All samples (S1,
S2 and S3) were cultivated at the National Corn
and Sorghum Research Center, Nakhon
Ratchasima province, Thailand for 33 months and
then the rhizomes of plai were harvested, cleaned
and chopped into small pieces for the experiment