Study On The Physiological, Biochemical And Cytology Change During Petal Senescence Of Osmanthus Fragrans

Osmanthus fragrans, one of the ten most famous flowers in China, is honoured of its fragrance. Because of the temporary flower phase and life span, the ornamental value of osmanthus is affected. The study focus on the modification of Eth, STS, 6-BA on the content level of protein and the activity of protective enzyme in the senescence period of osmanthus fragrans, and the result from cytological indicated that the petal senescence of osmanthus fragrans was a typical programmed cell death.The main results of this test were shown as follows:1 Except 25mg/L and 50mg/L, the treatments of concentrations of Eth all had obvious effect to inhibit flower diameter, shorten the life span of petal and leaf and decrease ornamental quality when osmanthus were treated with ETP at different concentration : 25mg/L, 50mg/L, 100mg/L, 200mg/L, 400mg/L. The results indicated that osmanthus was sensitive to ethylene.2 The content of protein in the treatment of 200 mg/L ETP was decreased quickly, and the protective enzymes, SOD and POD, were restrained. The treatments of 5 mg/ L 6-BA and 0.2mM STS promoted the activity of SOD and POD. The results implied POD has different feedback mechanism.3 The result from morphology and in situ end-labelling of fragmented DNA showed that the petal senescence was a typical programmed cell death which involved a series of events besides the nuclei gradually became irregular with highly condensed chromation, but the nuclear was one of the most stable components in the cell, it was among the last organelles disappeared during the autolytic process. The DNA fragment will be induced when the osmanthus were treated for 36h with 200 mg/L ETP. If the time of treatment were longer, the cell would be dead.