A Study On Some Physiological Changes In Postharvest Cut Flowers Of Chrysanthemum And Carnation

"Shiyue Bai" (Chrysanthemum morifolium L.) cut flower was used to investigate the temporal and spatial sequence in senescence of its flower and leaves. And the feasibility of chlorophyll fluorescence parameters as an indicator of senescence process of postharvest chrysanthemum was discussed. Results were described as following:1. C hlorophyll c ontent de clined g radually du ring t he p ostharvest c hrysanthemum senescence, accompanying with the obvious leaf aging related symptom. Low temperature inhibited the degradation of leaf chlorophyll, and extended the vase life.2. The significant decrease in chlorophyll fluorescence parameter Fv'/Fm', PS and qP preceded or paralleled with that of chlorophyll degradation in postharvest chrysanthemum. There existed a significant positive relationship between the changes in chlorophyll fluorescence parameter Fv'/Fm', ps, qP and chlorophyll content with correlation coefficient 0.4542** (Fv'/Fm'), 0.4772** (ps) and 0.4511** (qP), respectively. It suggested that the chlorophyll fluorescence parameter Fv'/Fm', ps and qP could be used as indicators to forecast the initiation of chlorophyll degradation and cut flower senescence.3. Temporal and spatial sequence existed in the senescence of chrysanthemum cut flower. The marked decrease in chlorophyll fluorescence parameter Fv'/Fm', Ops n and qP was earlier than the time-point of ethylene climacteric rise of the flower following the sequence observed in leaf yellowing and flower withering. The senescence of basilar leaves advanced that of leaves near the flower, and the senescence of leaves was prior to the flower."Ziyou Huang" Carnation (Dianthus caryophyllus L.) was used to study the effects of temperature, ASA and ACC treatments on regulating the senescence process of the flower. Observed results were described as following:1. Low temperature storage delayed flower abloom, inhibited fungus infection, thus prolonged the vase life of cut flower.2. ACC treatment promoted ethylene biosynthesis, advanced climacteric rise and peak appearence, and accelerated the petals wilt of carnation cut flower.