Biochemical diversity of global tea [Camellia sinensis (L.) O. Kuntze] germplasm and its exploitation: a review

Tea (Camellia sinensis L.) is the most widely-consumed beverage in the world. The biochemical components of tea leave include polyphenols (catechins and flavonoides), alkaloids (caffeine, theobromine, theophylline, etc.), volatile compounds, polysaccharides, amino acids, lipids and vitamins show a variety of bioactivities. Prolong cross-pollination nature of tea plants have produced considerable heritable variation, resulting in a high level of genetic diversity. The collection and conservation of the cultivars, landraces and wild relatives of the tea plant provides breeders with fundamental materials from which new cultivars are to be developed. The major role of tea breeding is to improve productivity, enhance tolerant to biotic and abiotic stress, and increase tea flavor and quality. Dissection of the genetic basis of these traits provides the potential for accelerating the breeding process by developing new tools such as marker-assisted selection. Therefore present review provides an overview of the biochemical and metabolite diversity of the global tea germplasm and its characterization and utilization.