DNA條碼應用於碧螺春及東方美人茶之品種鑑定

Abstract

茶樹為我國重要之經濟作物，因應各地不同的產製環境而發展出各種特色茶。近年發現有進口低價茶葉冒充或混雜國產特色茶之情況，甚或將進口茶葉冒充本國茶葉參加各特色茶區之比賽，為維護我國各特色茶區之發展，有必要區隔國產與進口茶葉。本研究以碧螺春及東方美人茶為研究對象，以M8R (細胞質DNA)及ITS2F (細胞核內DNA)兩組DNA條碼進行茶園茶樹樣品、市售茶、比賽茶及進口茶葉之品種鑑定。收集自碧螺春主要產區之市售茶及比賽茶均為青心柑仔品種製成，茶園可疑樣品之DNA條碼分析結果顯示尖葉種具有與青心柑仔相同之DNA序列，經ISSR DNA分子標誌分析後亦未發現多型性，另一懷疑為台茶16號之茶樹經DNA條碼分析後推測為台茶14號及台茶17號之雜交實生苗，來自青心柑仔與紅心大冇混植茶園之兩可疑樣品則分別為雜交所得之實生苗及青心柑仔變異種。而在東方美人茶主要產區內，大多數茶園所種植之品種為青心大冇品種，大部分比賽茶也為青心大冇品種所製成，但仍有少數東方美人茶係以台茶12號製成，另外亦發現一個核內DNA序列具有1個SNP變異之青心大冇變異種。DNA序列分析結果亦顯示中國進口之碧螺春係由青心柑仔或台茶12號品種製成，而進口之毛蟹品種則是以青心烏龍品種製成。此外本研究也建立黃柑、柑仔(黃)、紅心柑仔、烏金、武夷及大葉烏龍等茶樹品種之DNA指紋，可供未來品種鑑定之參考。本研究顯示以DNA條碼進行茶葉品種鑑定之效果良好，未來可配合產銷履歷制度進行特色茶葉產品區隔，以增進國產特色茶之發展。

Tea (Camellia sinensis) is one of the most important economic crops in Taiwan. Because of different growing and producing environments, each tea production area has its own unique tea. In recent years, some fake or adulterant imported tea varieties were found in the domestic markets or competition tea activities. To maintain the industry of unique tea in Taiwan, it’s necessary to distinguish domestic tea from imported tea. In this study, tea samples of Pi-Lou-Chun and Oriental Beauty Tea were analyzed by using M8R (organelle DNA) and ITS2F (nuclear DNA) DNA barcodes. These samples were collected from main production areas, markets, competition tea activities and China. All tea samples collected from main production areas of Pi-Lou-Chun and markets were verified as the variety Chin-Shin-Gan-Tzy. A mutant with acicular buds was identified with the same DNA sequences and ISSR DNA fingerprints as Chin-Shin-Gan-Tzy. One tea tree of suspected variety TTES No. 16 was identified as natural crossing between TTES No.14 and TTES NO. 17. Two suspected samples from tea garden of mixture planting of Chin-Shin-Gan-Tzy and Horng-Shin-Dah-Pan were a mutant of Chin-Shin-Gan-Tzy and a hybrid of these two varieties, respectively. Most plants grown in the main production areas of Oriental Beauty Tea were variety Chin-Shin-Dah-Pan, and most competition tea samples of Oriental Beauty Tea were identified as variety Chin-Shin-Dah-Pan. But some Oriental Beauty Tea samples were made by variety TTES NO. 12. Besides, a few samples of Chin-Shin-Dah-Pan with one SNP in nuclear DNA sequence were found. Imported tea labeled “Pi-Lou-Chun” was made of Chin-Shin-Gan-Tzy or TTES NO. 12, and imported tea samples of Mau-Hsei were verified to be made of variety Chin-Shin-Oolong. In addition, DNA fingerprints of varieties Hwang-Gan, Gan-Yzy (Yellow), Horng-Shin-Gan-Tzy, Wu-Jin, Wuu-Yi and Dah-Yeh-Oolong were established. This study has shown that DNA barcodes are very useful in variety identification of tea. For enhancing the unique tea industry in Taiwan, DNA barcodes could be applied with traceability system in the future.