Study On Physiological And Biochemical Characteristics In Flowering Stage Of Tree Peony

Using petals and leaves of different flowering stages of tree peony cultivar‘Fengdanbai’,‘Luoyanghong’ and ‘Yuloudiancui’ as test materials, the physiologicalchanges of the whole flowering stages were researched, and the flowering and agingmechanism, the relationship between leaves and petals and the different physiologicalmechanism of varieties were discussed. The test results were showed as follows:1. In whole flowering stage, the activities of petals was more intense. The contentof soluble sugar of different peony petals showed a single-peak trend, which roseearlier and declined later, while the content of starch decreased with the floweringstage. Protein content of petals degraded during the flowering period, at the same time,the relative electrical conductivity and MDA increased, and proline had a highercontent in the earlier stage, and dropped later. The petals antioxidant enzymes activityof different species changed different in the earlier flowering stage, the activity ofvarious enzymes was relatively low, then gradually raised with the flowering, and theenzymatic activity showed a low trend in the middle and later flowering stages. Theability of removing free oxygen radicals reduced, and the balance of free oxygenradicals was broken, then cell damage increased, thus the cells gradually senescenced.The results indicated that, the consumption of carbohydrates, the reduce of activity ofantioxidant enzymes and the decline of proline content, as well as the accumulation offree radicals and membrane lipid peroxidization, were the important factors of peonyflower senescence.2. The physiological mechanism of different varieties peony petals existed somedifference, which mainly concentrated in the ratio of dry weight and fresh weight, therelative electric conductivity, the activity of SOD, POD and CAT, proline and MDAcontent, etc.3. In the flowering and aging period, the content of soluble protein of peonyleaves increased slightly, while the relative electric conductivity and MDA was fairly constant, and the leaves did not showed synchronous aging with petals. Due to thedifferent sensitivity to reproductive inhibiting, three kinds of tree peony showed adifferent physiological mechanism of leaves in the flowering stage, which mainlydisplayed in MDA content, the tend of proline and antioxidant enzymes activity, etc.