贵州名优茶与产地土壤矿质元素相关性及其溯源影响的研究

Study on the Relationship Between Guizhou Famous Tea and Mineral Elements in Soil and Their Traceabilitys

为探究贵州省名优茶产地不同深层土壤对茶叶矿质元素溯源效果的影响,以土壤-茶叶的多矿质元素法结合主成分分析(PCA)、反向传播(BP)神经网络法、逐步线性判别分析(SLDA)对茶叶产地进行溯源。结果显示,不同产地的茶叶和土壤具有独特的矿质元素指纹,茶叶中Fe、Mn、K、Ca、Mg、Cu的含量与土壤中对应元素含量显著相关(P<0.05),以这6种矿质元素含量结合PCA可有效区分茶叶的地理起源;不同深层土壤对茶叶产地的溯源有不同影响,通过SLDA法、BP神经网络法明确了以60~80 cm的土层进行产地溯源的效果最优,产地溯源验证判别率分别为98.5%(SLDA法)和100%(BP神经网络法),并基于SLDA法确定了Zn、Cu、P、Mn、Fe、Mg和K 7种元素构建的贵州名优茶产地溯源模型。此外,研究发现茶叶产地溯源几乎不受茶树品种的影响。本研究结果为贵州省名优茶矿质元素指纹图谱的建设及土壤-茶叶产地溯源的关系研究提供了理论依据。

In order to explore the influence of different deep soils of famous and high-quality tea producing areas in Guizhou Province on the traceability effect of tea mineral elements,the tea producing areas were traced by soil tea multi mineral element method combined with principal component analysis(PCA),BP neural network method and stepwise linear discriminant analysis(SLDA).The results showed that tea and soil from different producing areas had unique mineral element fingerprints.The contents of Fe,Mn,K,Ca,Mg and Cu in tea were correlated with the contents of elements in soil(P<0.05).The geographical origin of tea could be successfully distinguished using the contents of these six mineral elements combined with PCA.Different deep soils have different effects on the origin traceability of tea.Results of SLDA and BP neural network show that the effect of origin traceability in 60~80 cm soil layer is the best.The discrimination rates of origin traceability verification are 98.5%(SLDA method)and 100%(BP neural network method),respectively.The origin traceability model of famous high-quality tea in Guizhou was constructed using Zn,Cu,P,Mn,Fe,Mg and K.In addition,the origin traceability of tea was hardly affected by tea varieties.The results provide a technique support for the construction of mineral element fingerprints of famous and high-quality tea in Guizhou Province.