Achievements and prospects of QTL mapping and beneficial genes and alleles mining for important quality and agronomic traits in tea plant (Camellia sinensis)

Tea is one of the most significant non-alcoholic beverages globally due to its unique secondary metabolites. Therefore, it is essential to apply molecular technologies in conjunction with various phenotypes for candidate gene mining and identification, regulating the synthesis and degradation of secondary metabolites contributing to tea quality, in order to enhance effective tea breeding. To date, there are various tea genetic resources and numerous high-density genetic maps owing to the progress and development of the tea plant genome. In this review, we comprehensively reflect the mining and identification of quality-related candidate genes using quantitative trait loci (QTL) mapping and genome-wide association study (GWAS) in tea plants in recent years. Functional verification and promotion of these candidate genes were also discussed.