Heterosis for Catechins and Caffeine in Kenyan Tea (Camellia sinensis) (L.) O. Kuntze).

Tea quality is manifested in its aroma, flavour and taste properties, which are generated by volatile and non-volatile compounds, mainly catechins and caffeine. Several studies have revealed positive significant relationships between (flavan-3-ols) catechins and caffeine in green leaf and black tea quality. Additionally, the health benefits of tea in management of cancer, arthritis, cardiovascular diseases, diabetes and obesity have been attributed to catechins and caffeine. Eight biochemical traits of tea were used to investigate mid-parent heterosis (MPH), better parent heterosis (BPH) and standard heterosis (SDH) in a 4x4 diallel mating design. Overall, genotype x environment interaction influenced heterosis. For example, mean GA, EGC, C, EC and TC contents were higher at Timbilil compared to Kangaita while mean Caffeine, EGCG and ECG were higher at Kangaita compared to Timbilil. The results also showed that, inbreds (EPK TN14- 3, AHP S15/10 and TRFK 6/8) had improved catechins content and could be used in recurrent selection to develop tea with high catechins content. Crosses, which showed high positive heterosis over the mid-parent, better parent and the standard variety, could be utilized to generate transgressive segregants in the later generations with high catechins and caffeine.