In an attempt to differentiate the origin of raw materials in the processed green tea, three different tea plantations were chosen and samples of the roasted and the fermented green tea were collected from where they had been processed with fresh leaves harvested from each tea plantations. Random Amplified Polymorphic DNAs (RAPD) techniques were applied to differentiate their origins and the results obtained were as follow:
1. While intact DNAs of high molecular weight were routinely purified from fresh leaves, most of DNAs were founded to be degraded and less than 1.0 Kb in their size in the processed green tea materials of either roasted or fermented products when fractionated on the agarose gel by electrophoresis.
2. The value of A260/A280 was ranged from 1.0 to 1.8 when DNA was extracted by CTAB method while it was ranged from 1.8 to 3.7 by Kit method. In addition, the value of A234/A260 was ranged from 1.2 to 2.5 from the DNA extracted by CTAB method whereas it was in the range of 0.1 to 0.4 for when DNA was extracted by Kit method.
3. RAPD analyses with the genomic DNAs from fresh leaves indicated that 23 to 53% of produced DNA fragments were polymorphic DNAs when random primers was used for PCR amplification so that three different lines were able to be easily differentiated. In contrast, no such polymorphic DNA bands were produced from either roasted or fermented green teas.
4. The genetic similarity coefficients were calculated from polymorphic DNA patterns obtained with the genomic DNAs of fresh leaves by using an XLSTAT program. The lowest value was 0.632 between line A and line B with a random primer 1 while the highest value (0.900) was obtained between line B and line C with a random primer 2. These results indicate that line A and line B are genetically more closed than line C although their origins were not able to be distinguished from their processed products since no such polymorphic bands were generated by these RAPD analyses.
5. In summary, it is suggested that more refined techniques such as single nucleotide polymorphic markers of a particular gene fragments are required to differentiate their origins from the processed green tea.