Studies On Ultraweak Luninescence And Physiological And Biochemical Metabolism Of Chrysanthemum

In order to investigate the physiological and biochemical metabolism of chrysanthemum during the stage of floral differentiation, of rooting of cutting and of the the stress of low temperature and poor light, we used Dendranthema grandiflorium (Ramat.) Kitam.'Jinba'as materials.In the rooting of cutting experiment, the shoots were about 8~10 cm long,and they were treated respectively with distilled water, NAA and NAA+CaCl2, we studied ultraweak luninescence and physiological and biochemical and metabolism during the process of rooting of cutting.In the floral differentiaton experiment, When the length of plants were about 40~50 cm, we treated plants respectively with short-day(daylight 8 h/night 16 h)and long-day(daylight 16 h/night 8 h), then we studied ultraweak luninescence and physiological and biochemical metabolism during the five stages of floral differentiation. In the stess of low temperature and poor light experiment,When the length of plants were about 40~50 cm, they were treated with the normal temperature and light (22℃/18℃, PFD 450μmol·m-2·s-1), the combination of lower temperature and poor light (16℃/12℃, PFD 100μmol·m-2·s-1), critical temperature and poor light (12℃/8℃, PFD 60μmol·m-2·s-1) stress for 11 days, then we studied ultraweak luninescence and physiological and biochemical metabolism in the 11days. The results showed as follows:1.The UWL intensity of the leaves of chrysanthemum increased 119.31%, respiration rate increased by 102.42%,content of ATP, soluble sugar and soluble protein of the leaves of chrysanthemum increased by 148.61%, 95.53%, 32.52% respectively at initial stage of floral bud differentiation (II) compared with those of vegetative stage of apical bud (I), and then UWL intensity, respiration rate and content of ATP reduced slowly respectively at stage of involucre primordial differentiation (III), stage of floral primordial differentiation (IV) and stage of crown form (V). Content of soluble sugar decreased mostly at stage IV and stage V, and the levels neared to those of controls. Content of soluble protein maintained higher levels at stage II, stage III, and stage IV, decreased mostly at stage V, but it still increased by 14.00% compared with those of controls. But all of UWL intensity, respiration rate, and content of ATP, soluble sugar and soluble protein maintained stable status in all stages of controls of non-short day treatments.This suggested that the UWL has close relation to respiration and energy metabolism of leaves during differentiation of chrysanthemum.2.The intensity of ultraweak luminescence, fluorescence and phosphorescence, and content of DNA and RNA of the leaves of chrysanthemum were increased by 119.31%, 33.41%, 41.32%, 62.21% and 32.12% respectively at initial stage of floral bud differentiation (II) compared with those of control plants, then intensity of ultraweak luminescence, fluorescence and content of DNA reduced slowly respectively at stage of involucre primordial differentiation (III), stage of floret primordial differentiation (IV) and stage of crown form (V), while phosphorescence intensity and RNA content increased continuously, and then decreased. But all of indexes of above maintained stable status during all stages of controls of non-short day treatments.This suggested that the bioluminescence intensity increased, and close relative to nucleic acid metabolism of leaves during differentiation of chrysanthemum.3.The UWL intensity, SOD, POD and CAT activity of the leaves of chrysanthemum increased quickly at first but decreased quickly after that, finally they tend to be stable during floral differentiation in chrysanthemum. O2.- prodution rate increased 58.00% at initial stage of floral bud differentiation (II). All of these indictors were higher in short day condition than in long day condition.moreover, they maintained stable status in long day condition. All the results showed that reactive oxygen species were one of the reasons of UWL prodution. All kinds of antioxidase can indirectly influenced the prodution of UWL through regulation of reactive oxygen species. This suggested that UWL is close relative to O2.- prodution.4.The UWL, fluorescence and phosphorescence of the leaves of chrysanthemum have a regular variation during the process of rooting of cutting, UWL and fluorescence of cutting slips treated by distilled water have a higher value during the 0 day and the 15 days after treatment.The regularity for chang of phosphorescence is opposite to fluorescence.Relevance analysis indicates that fluorescence has a significant positive correlation with UWL, phosphorescence has a significant negative correlation with UWL.UWL and fluorescence of cutting slips treated by exogenous growth hormone is higher than the cutting slips treated by distilled water, furthermore, the value of cutting slips treated by NAA and CaCl2 is the highest. This suggested that UWL can relect the condition of rooting of cutting in chrysanthemum .5.The UWL intensity will increase when stress degree increasing and time prolonging.The SOD activity of the leaves of chrysanthemum continually increased during the stress for days under stress of lower temperature and poor light, but SOD activity increased in the earlier stages (1~5 d) and decreased in the later stages (5~11 d). Membrane permeabilities, POD activity increased, while membrane lipid peroxidization pricked up, following MDA accumulation in chrysanthemum leaves with stress degree increasing and time prolonging.The effects of stress of lower temperature and poor light more obvious than the stress of critical temperature and poor light.