Study On The Characteristics Of Wheat Multi-element Fingerprinting Information About Geographical Origin

Multi-element fingerprinting technique has been successfully applied to discriminate geographicalorigins of various agricultural products. The main objective of this dissertation was to study the formingreason of multi-element origin fingerprints of agricultural products and their stability among differentyears. It could provide theoretic basis for the practical application of identifying the geographical originof agricultural products by multi-element fingerprinting technique. Wheat was chosen as theexperimental model organism in this study. A total of240wheat samples were collected randomly fromHebei, Henan, Shandong and Shaanxi provinces during the2008and2009harvest time, respectively. Theconcentrations of multi-elements in wheat kernel samples were determined by inductively coupledplasma mass spectrometry (ICP-MS). Combined with one-way analysis of variance, principal componentanalysis (PCA) and linear discriminant analysis (LDA), the feasibility of multi-element analysis inidentifying the geographical origin of wheat was discussed. Field experiments were conducted at threedifferent locations: Zhaoxian (Hebei province), Huixian (Henan province), and Yangling (Shaanxiprovince). Ten wheat varieties were cultivated on each of three agricultural fields during the2010and2011wheat seeding time, respectively.180wheat samples were obtained from the model experiment. Theconcentrations of55elements in wheat kernel samples were determined by high resolution inductivelycoupled plasma mass spectrometry (HR-ICP-MS). Combined with multi-way analysis of variance, theinfluence of location, genotype, harvest year and their interactions on multi-element fingerprints of wheatkernel were analyzed. The contributions of location, genotype and harvest year to the observed elementcontent variability were calculated by the variance component ratio σ2i/σ2total(σ2i=square sum of varianceof certain factor; σ2total=total square sum of variance). The element fingerprinting information closelyrelated to geographical origin was selected.61pairs of wheat and soil samples were randomly collectedfrom Hebei and Henan provinces during the2010harvest period. The concentrations of55elements inwheat kernel and their provenance soil samples were analyzed by HR-ICP-MS and X-ray fluorescence(XRF). The influence of multi-element contents of topsoil and parent soil samples on those of wheatkernel were analyzed, respectively. And the element fingerprinting information closely related to topsoilor parent soil was selected.1202008/2009wheat kernel samples from Hebei, Henan, Shandong andShaanxi provinces were chosen as the experimental materials to examine the origin discrimination effectof the selected fingerprinting information to wheat samples from non-experimental environment.Through above analysis, the forming reason of wheat multi-element origin fingerprints was made clear.The accurate and stable origin traceability fingerprinting information was selected.The main conclusions were as follows:(1) The multi-element contents in wheat samples from different regions were significantly different. Itwas feasible to classify wheat according to the geographic origin using multi-element fingerprintingtechnique.(2) The origin effect was observed to be strongest on Ca, Mn, Zn, Rb, Sr, Mo, Cd and Cs content variabilities; genotype effect was strongest on Cu content variability; year effect was observed to bestrongest on Na, Mg, Al, Ti, V, Cr, Fe, Co, Ga, Se, Y, Zr, Sn, Eu and U content variabilities.(3) The significant correlations existed for the element Cr, Mn, Ga, Rb, Sr, Zr and Cd contents betweenwheat kernel and topsoil and for the element Na, Mn, Cd, Sn and Ba contents between wheat kernel andparent soil.(4) The origin discrimination effect of the elements Ca, Mn, Zn, Rb, Sr, Mo, Cd and Cs to wheatsamples from non-experimental environment was good. The information contained in these8elementswas perfect for wheat traceability of geographical origin.(5) The study results of the model experiment of geographical origin traceability by multi-elementfingerprinting using wheat as model organism can provide reference for building the technical system oforigin traceability of agricultural products.