Detection and characterization of caffeine-less tea plants originated from interspecific hybridization

Two tea plants containing little caffeine (caffeine-less) were found in a population derived from natural crossings of an interspecific hybrid 'Cha Chuukanbohon Nou 6' (Camellia taliensis × C. sinensis). Two caffeineless plants showed low caffeine content and rather high theobromine, which is a precursor of caffeine, whereas all tested tea (C. sinensis) cultivars including 'Cha Chuukanbohon Nou 6' were observed high caffeine/low theobromine contents. Component analysis by HPLC showed that 'Taliensis-akame' (C. taliensis), which is the seed parent of 'Cha Chuukanbohon Nou 6', showed low caffeine content and rather high theobromine and may be a caffeine-less character donor. Pedigree analysis using SSR markers suggested that parentoffspring relationship was found between tea plants related to caffeine-less tea breeding lines. Therefore, it is considered that caffeine-less character of caffeine-less plants could be inherited recessively from 'Taliensis-akame' via 'Cha Chuukanbohon Nou 6'. Preliminary genetic analysis using 33 progenies of 'Cha Chuukanbohon Nou 6' suggested the possibility that the caffeine-less character might be controlled by one recessive locus. Caffeine-less tea plants found in this study, will be efficiently used for genetic resources to introgress caffeine-less traits to tea cultivars in breeding programs.