Effect Of TDZ Pretreatment On Senescence Of Cut Cleyera Japonica

Cleyera japonica is used as primary cut branches in Japan. China’s annualexports account for65%of the total demand of Japan, producing enormous socialand economic benefits. In the research, a new plant growth regulator TDZ (thid-iazuron) was applied as pretreatment solution of Cleyera japonica. The optimumconcentration was screened out through concentration gradient test and was sppliedto study the mechanism of TDZ by plant physiological indicators and chlorophyllfluorescence parameters. It also studied the effect of TDZ pretreatment combinedwith low-temperature storage in order to learn senescence mechanism of Cleyerajaponica.The res-ults are as follows:1.The effect of of TDZ pretreatment under different concentration on senescence of cut CleyerajaponicaTreated with0μM,10μM,100μM,500μM,1000μM (NaOH as cosolvent)and1000μM (ethanol as cosolvent) concentration of TDZ solution, for24h pulsebefore in bottle, the results show that, compared with control,10-500μM TDZ pulsetreatment can increase the rate of fresh weight and delay senescence;100μM TDZpulse treatment could delay senescence for13.7days.2. The research of TDZ pretreatment on aging mechanism of cut Cleyera japonicaWith100μM TDZ pretreatment, the content of chlorophyll, the activities of per-oxidase (SOD) were increased, protein and malondialdehyde (MDA) were delyed.With the PAM-2500portable chlorophyll fluorometer, chlorophyⅡfluorescenceparaeters of the leaves of cut Cleyera japonica during the vase time. The results showthat Fo, qN raise, Fv/Fm, Yield, qP and Fv ’/Fm’ dropped. and Fv/Fm, Fv′/Fm′canbe used as the kind of accurately, quickly and without damage prediction needle onsenescence of cut Cleyera japonica3. The Effect of TDZ pretreatment combined low temperature on senescence of cut CleyerajaponicaIt was studied for the effect on quality, physiological and biochemical, bysoaking in the TDZ pretreatment solution for24h at the base of the branches andthen keeping at2-4℃environment for37days of wet storage. The results showethat pretreatment of TDZ combined with the low-temperature storage could delaythe yellowing, slow soluble protein and chlorophyll content, and enhance the CATand SOD activities, reduce MDA content, and increase the vase life of cut branches. In short, compared to control, TDZ pulse treatment with low concentration hassignificant effect of preservation of cut branch; Fv/Fm and Fv′/Fm′can be used asthe kind of accurately, quickly and without damage prediction needle on senescenceof cut Cleyera japonica;100μM TDZ pretreatment has significant effect ofpreservation of cut branch.