Abstract: Application of cytokinin growth regulators, KT (Kinetin ) ,6-BA(Benzyladenine ), andCPPU [N-( 2-chloro-4-pyridyl) -N'-pheuylurea] on delaying senescence of harvested broccoli florets was studied. The results showed that use of KT, 6-BA or CPPU on harvested broccoli delayed floret yellowing and chlorophyll degradation, decreased respiration and ethylene production rate, postponed climacteric time, and retarded membrane permeability loss. The content of endogenous ABA was lower and the levels of IAA and GA were higher in the broccoli treated with 6-BA and CPPU than those in the control during 12 - 84 h. The treated effects enhanced with increasing concentration in the study. The CPPU treatment (40 mg·L ^-1) was most effective in delaying the broccoli yellowing, followed by 6-BA and KT.

Key words: broccoli, cytokinin, senescence, hormone