Changes in endogenous cytokinin activity during seed development in Tea

The role of endogenous cytokinin activity was examined in tea seed during development that was divided into 6 stages. Cytokinin activity similar to zeatin (Z), zeatin ribosides (ZR) and iso-pentyl adenine (IPA) increased with advance in seed growth. Cytokinin activities (especially of Z and ZR) continued to increase from the liquid endosperm stage (i. e. stage 6) when histo-differentiation occurred to finally rise to a maximum at stage 8 or the early embryo maturation stage during which 90% of the endosperm was consumed by the growing embryos. Later, cytokinin activity similar to Z and ZR decreased from stage 9 (late embryo maturation stage). Although cytokinin activities declined during full maturity (stage 10), yet maximum activity was still detected in the form of cytokinin glucosides at this period.