Screen and Genetic Assessment of Tea Germplasms with Elevated Methylated Catechin, (−)-Epigallocatechin-3-O-(3-O-methyl)gallate

Abstract

The aim of this research was to identify tea varieties containing high levels of catechin methyl ester that could be used as important sources for genetic breeding and in the production of high quality tea. We examined 113 species that have been preserved in the Taitung Branch of the Tea Research and Extension Station of Taiwan (TTES). The average level of (-)-epigallocatechin-3-O-(3-O-methyl) gallate (EGCG3''Me) was 0.45% for all varieties screened. Among them, 16 varieties with higher EGCG3''Me content (>0.8%) were considered good candidates for manufacturing partially fermented tea. Analysis of these tea varieties revealed that the EGCG3''Me content in leaves did not correlate with the caffeine content. Genetic assessments revealed that the lengths of their internal transcribed spacers (ITS) were in the range of 638-670 bp and that the sequence identities were in the range of 0.690-1. Two major groups were constructed by phylogenetic analysis, I and II, with a genetic distance of 0.08 based on the ITS1-5.8S-ITS2 sequences between the ribosomal genes. Our results provide genetic information about tea varieties with elevated EGCG3''Me content and indicate the need for a comprehensive genetic assessment of tea germplasms preserved in the TTES to better serve the future of tea breeding.

Changes in Non-Volatile and Volatile Metabolites Associated with Heterosis in Tea Plants (Camellia sinensis)

“…The EGCG content of tea plant hybrids and maternal TGY was significantly higher than that of paternal HD. 3″-Methyl-epigallocatechin gallate (EGCG″3Me) is an O-methylated EGCG that naturally exists in some tea germplasms, , which is stronger than EGCG in some health functions . Hybrid HGY and maternal TGY contained higher levels of EGCG″3Me (>5 mg/g), which was significantly higher than hybrid JGY and paternal HD.…”

Quantitative Trait Loci Mapping for Theobromine and Caffeine Contents in Tea Plant (Camellia sinensis)

“…These plants have been utilized for more than 2000 years in China, where they were originally used for traditional medicine and subsequently for food and drinking. Recent research on phytochemical analysis of tea extracts has identified many bioactive compounds, such as flavonoids, methylxanthines, l -theanine, and polysaccharides. − These versatile natural metabolites have not only contributed to the unique taste and flavor of tea but also proved to have powerful health-promoting effects, − which has raised a growing interest in and consumption of tea and relative products containing tea constituents.…”