National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China; College of Horticulture & Forestry Sciences, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China; Zhejiang A & F University, Hangzhou, Zhejiang 311300, PR China.
National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China; College of Horticulture & Forestry Sciences, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China.
Ecotoxicol Environ Saf. 2024 Sep 15;283:116785. doi: 10.1016/j.ecoenv.2024.116785. Epub 2024 Jul 26.
Tea tree is a fluorine (F)-enriched plant, leading to much concern about the safety of drinking tea from tea tree (Camellia sinensis (L.) Kuntze). Tea tree is a perennial leaf-harvested crop, and tea production in China is generally categorized as spring tea, summer tea and autumn tea in its annual growth rounds. However, the seasonally dynamic changes of F content and accumulation in the leaves and its drinking safety are poorly understood. In this study, 85 tea varieties cultivated under the same conditions were investigated to analyze the seasonal variation of F content and it's relationships with F accumulation, aluminum (Al), calcium (Ca) and manganese (Mn) and hazard quotient (HQ) in young leaves (one bud and two leaves, YL) and mature leaves (canopy leaves, ML). The average F contents and accumulations were 350 mg kg and 203 g ha in YL, and they were 2451 mg kg and 2578 g ha in ML, respectively, with F mainly accumulated in ML. As the growing season progresses, the F content showed a gradual increase in YL, while a decrease in ML, inferring that F may be redistributed from mature leaves to young leaves. Additionally, the F content was quite different among tea varieties which are suitable for processing oolong tea, green tea, and black tea, with higher F accumulation in oolong tea varieties than in green and black tea varieties. Moreover, F content and accumulation could be obviously affected by the geographical origin of the tea tree varieties, with significantly higher F content in the varieties from F rich fluorite belts than other regions. Furthermore, F content and accumulation showed a significant positive correlation with the content of Al and Mn (p < 0.05). Based on a daily tea consumption of 8.7 g, the HQ was investigated to show that the proportion of tea leaves with HQ<1 made from spring, summer and autumn tender leaves of 85 varieties was 100 %, 90.6 % and 50.6 %, respectively, indicating that the tea with the best drinking safety comes from spring, followed by summer, and then autumn. This result suggests that it could be necessary to avoid planting tea trees in fluorite mining areas, choose low F tea tree varieties, and control the tenderness of fresh leaves in order to ensure the safety of tea drinking.
茶树是一种富氟植物，这引起了人们对饮用茶树（Camellia sinensis (L.) Kuntze）茶安全性的担忧。茶树是一种多年生叶用作物，中国的茶叶生产一般在其年生长周期中分为春茶、夏茶和秋茶。然而，茶树叶片中氟含量及其季节性动态变化和积累以及饮用安全性还知之甚少。本研究调查了 85 个在相同条件下种植的茶树品种，分析了氟含量的季节性变化及其与氟积累、铝（Al）、钙（Ca）和锰（Mn）和年轻人叶片（一芽两叶，YL）和成熟叶片（树冠叶片，ML）中危害系数（HQ）的关系。YL 中的氟含量和积累平均值分别为 350mgkg 和 203gha，ML 中分别为 2451mgkg 和 2578gha，氟主要积累在 ML 中。随着生长季节的进行，YL 中的氟含量逐渐增加，而 ML 中的氟含量则减少，这表明氟可能从成熟叶片重新分配到幼叶中。此外，不同适制乌龙茶、绿茶和红茶的茶树品种之间的氟含量差异很大，乌龙茶品种的氟积累量明显高于绿茶和红茶品种。此外，茶树品种的地理来源对氟含量和积累有明显影响，来自富氟萤石带的品种的氟含量明显高于其他地区。此外，氟含量和积累与 Al 和 Mn 的含量呈显著正相关（p < 0.05）。基于每天 8.7g 的茶叶消耗量，调查了 HQ，结果表明 85 个品种的春、夏、秋嫩梢茶 HQ<1 的比例分别为 100%、90.6%和 50.6%，表明饮用安全性最好的茶来自春茶，其次是夏茶，然后是秋茶。这一结果表明，有必要避免在萤石矿区种植茶树，选择低氟茶树品种，并控制新鲜叶片的嫩度，以确保饮茶安全。
