Single Nucleotide Polymorphism Genotyping And Application Of Fujian Oolong Tea(Camellia Sinensis) Germplasm Resources

Oolong tea is one of the six major types of tea.Among them,the processing technology of oolong tea is the most complicated,and its germplasm resources are the most abundant.Fujian is the origin and main producing area of oolong tea.Oolong tea is the largest output kind of tea product in Fujian province.However,the genetic background of oolong tea germplasm resources is not clear,which limits the development of tea breeding and tea industry.In addition,oolong tea products are generally named after their tea plant varieties.At present,there are a total of 5 oolong tea Geographical Indication Products in Fujian Province,which specify the varieties material required by each category.Varietal identification to protect the reputation of oolong tea is important.In this study,Fujian oolong tea varieties and oolong tea products were used as the main research materials.In combination with oolong tea varieties in Guangdong and Taiwan,96 pairs of primers screened from the tea tree’s expressed sequence tag(EST)database were verified.SNP technology was performed to analyze the genetic diversity of oolong tea varieties and the source of varieties of tea products.The study accurately and effectively determined the genetic relationship among Chinese oolong tea germplasms.It provides an effective tool for protecting the diversity of tea germplasm resources,with a view to assisting future breeding work and authenticity identification of oolong tea products.The main results of this study are as follows:1.EST-SNP genotyping and genetic relationship analysis of oolong tea varietiesAs one of the most popular Chinese tea products,Oolong tea involves the most complicated manufacturing process and the most abundant tea germplasm resources.However,the unclear genetic backgrounds of Oolong tea germplasms have been biological limitations for tea breeding and quality control.In this study,highthroughput SNP technology was used to analyze the genetic diversity of 98 Oolong tea landraces and cultivars.Ninety-six pairs of primers were selected and validated from the expressed sequence tag(EST)database of Camellia sinensis.The results verified 75 SNP loci that are able to accurately and efficiently determine the genetic relationships among Chinese Oolong tea germplasms.The DNA fingerprints of 4 main Oolong tea-producing areas were constructed by tracing the information of each site of the SNP.The Guangdong Oolong tea germplasms were a relatively distinct group,while the genotypes of Taiwan Oolong tea were similar to those of populations in Fujian.The tea germplasms in Southern and Northern Fujian had the largest intersections,and they also showed their own characteristics.Our results provide guidance for the identification,integration and selection of parents for tea plant germplasms.Moreover,our study provides an effective tool to protect the diversity of tea germplasms and to assist in future breeding work.2.Genetic relationship between Dahongpao and its releated varieties by ESTSNP For the first time,the study used high-throughput SNP technology to clear theoriginal source of the 6 tea trees on the rock wall of the "Dahongpao" in Jiulongke,Tianxinyan,Wuyi Mountain,while supplementing the maternal source of the"Jiulongpao" variety.The results of hierarchical dendrogram and PCoA principal component analysis showed that the genotypes of Jiulongke 1#and Jiulongke 5#were consistent."Beidou" is relatively close to Jiulongke 1#and Jiulongke 5#but they are different.The genotypes of Jiulongke 2#and Jiulongke 6#were consistent with the"Dahongpao".It can also be seen from the evolutionary tree that the relationship between Jiulongpao,Jiulongke 2#and Jiulongke 6#is close.Therefore,this study first verified the parent-offspring relationship between "Jiulongpao" and "Dahongpao".3.Accurate varietal authentication of Tieguanyin products based on EST-SNPMinnan oolong tea is one of the most popular tea in China.The growing demands and premium prices lead to the adulteration of famous Minnan oolong tea,e.g.Tieguanyin.In this study,single-nucleotide polymorphism(SNP)biomarker technology was used for the first time to authenticate the varieties of Minnan oolong tea products.There are 15 products of Tieguanyin product purchased from 3 different channels,and 3 samples of each product are randomly selected for DNA extraction and SNP high-throughput experiments.Forty-eight pairs of primers were screened in this work,which can be used to authenticate Tieguanyin products in high-throughput SNP chips at low cost and high efficiency.Through the analysis of NJ tree,PCoA plot,the study found that adulterated products account for 37.78%of Tieguanyin products,and the most frequently adulterants of Tieguanyin on the market is"Benshan" variety.And for the first time,the commercial behavior of using"Fuyun6hao" and "Jinguanyin" as adulterants or contamination for the production of Tieguanyin was reported.Through high-throughput EST-SNP,this research has proposed Tieguanyina rapid authentication technology for the market supervision and promoting consumer’s trust of Minnan oolong tea.