The Effects Of Different Light Intensities And Exogenous Sucrose Concentration On Petal Color And Photosynthesis Characteristic Of Paeonia Suffruticosa 'LuoYangHong'

With a randomized block design, on the condition of different light intensities and sucrose concentration , the petal color and photosynthesis characteristic of Paeonia suffruticosa cv.'LuoYangHong' were studied systematically. The results showed that: the major anthocyanidin in the petals of Paeonia suffruticosa cv.'LuoYangHong' is identified as peonidin, and the anythocyanin is peonidin 3,5-glucoside. Peonidin 3,5-glucoside is fuchsin, which decides the petals color of Paeonia suffruticosa 'LuoYangHong'. The light intensities could promote the synthesis of anthocyanin; the relationship between anthocyanin content under 20% light intensities and sucrose contents was very remarkable, but the best appropriate concentration and spraying time is not confirmed yet. The relationship between reductive sugar content in petals and light intensities was very remarkable, too. With the light intensities intensified, the content of reductive sugar increases; sucrose could promote the content of reductive sugar, the lower are light intensities, the more obvious is effect, and the effect of 0.3 mol·L^-1 is the most visible. The light compensation point of Paeonia suffruticosa cv.'LuoYangHong' was about 45μmol·m^-2·s^-1, and the light saturation point was around 1500μmol·m^-2·s^-1, which indicated that it is photophilic plant. The curves of annual variation of net photosynthetic rate(Pn) in the three different light intensities were all single-peak ,between April and June, the Pn was always a upper level. Under different light intensities, the diurnal course of the net photosynthetics rate(Pn), stomatal conductance(Gs), intracellular concentration of CO₂(Ci) were consistent on the whole. The diurnal variation of Pn is single-peak curve, one of Ci is shape of "V", the other of Gs is double peaks curve, and the time of appearance peak value of Gs is not consistent with Pn's, the reason possibly is that soil is thirsty moisture intimidate, the diurnal variations of the photosynthesis characteristic were accordant by spraying different sucrose concentration solutions in full light intensities. Spraying sucrose solutions effected on the diurual course of Gs, the reasion possibly is that sucrose solution block the ope of air vent. According to this experiment's conlusion as is concluded: light intensities had influence on petal color and the photosynthesis greatly. A shortage of light debases the quality of view and admire, but can delay and prolong florescence. Complementing proper light redound...