Studies Of Mechanisms And Techniques Of Pretreatments By Ultrasonic Wave, And/or Preservative Solution On Postponing Senescence Of 'Samamtha' Cut Rose

Vase life and Fresh Weight Changes in cut rose 'Samantha' under different combinations with the frequency, power and duration of ultrasonic wave were studied, the best combination was screened out and used to pretreat cut rose.Effects of ultrasonic wave (UW), and/or preservative solution (PS) pretreatments on ornamental qualities were studied, and different preservative mechanism of above three pretreatments were discussed at the physiological level, such as, water relationship, membrane stability, plant hormones dynamics and molecular metabolism, within 6h in vase and during the whole vase period, Market foreground of application of UW on postharvest handling of 'Samantha' were perceived and evaluated.Study on frequency, power and duration of pretreatment by UW showed that the lower frequency of 25 OOOHz is better than the higher of 40,OOOHz, the power of 70W is better than those of 40w and 100W, and the effects of pretreatment duration varied with different frequency and power. In collection, pretreatment of 25 OOOHz, 70W and 60min is the best combinations on delaying senescence of Samantha' .The three pretreatments all prolonged the vase life, increased the flower diameter and fresh weight of 'Samantha' , the sound effects in turn : UW+PS>PS>UW.The studies of mechanisms of these three pretreatments showed that, contrasted with the control, they all improved the water condition in 'Samantha' cut rose within 6h in vase and during whole vase in different degree. That is, they increased water uptake and improved water balance of flower by enhancing the water potential of different positions in flower stems and relative water content of different parts in flower branches. In addition, they restrained the water loss, superoxide anion production, increased lipid peroxidation production, membrane permeability and ABA content, furthermore, those three pretreatments increased the contents of CTKs, soluble sugar and sucrose and SOD activity during vase, and postponed declines of SOD activity during anaphase. Above mentioned effects were UW+PS>PS>UW in turn. Pretreatments by UW or PS alone resulted in the relative outstanding effects during prophase or anaphase leave each other.Estimations of UW preservative effects showed that pretreatment of UW represented short-term and long-term effects respectively. UW more remarkably promoted water uptake (included preservative solution uptake) and good water balance than the pretreatments of UW+PS and PS within 2-4h after pretreatment, but also stimulated water loss and correlative disadvantages on membrane stability and hormones balance, which could be repaired within short-term. UW pretreatment exhibited better effects than the controlduring the whole vase period. At last, the advantageous and disadvantageous effects of short-term and long-term by UW, and progressive effects of combination UW with PS were discussed.