Preservation Methods Of Daylily And Effect Of 2,4-Epibrassinolide On The Physiological Metabolism Of Daylily

In this paper,the "Dawuzui" daylily was used as the material to get the better preservation method and explore the preservation mechanism.The effects of packaging methods,chitosan treatment and 2,4-epibrassinolide treatment on the storage quality of daylily was studied to obtain the optimal conditions,then that was compared to get the better preservation method.The effects of the better preservation method in relation to reactive oxygen metabolism and endogenous hormones content were analyzed.The main results were as follows:1.In order to evaluate the effect of three methods,the effects of packaging methods,chitosan treatment and 2,4-epibrassinolide treatment on storage quality were investigated with the indexes of good flower rate,weight loss rate and a*value.The results showed that packaging was the key factor that influences storage quality of daylily,and greatly delayed the wilting of daylily.The preservation effect of nano-packaging was better than that of polyethylene(PE)packaging.Chitosan of high concentration could cause quality deterioration,the preservation effects of lOg/L chitosan treatment was better.10 g/L chitosan treatment group had relatively higher good flower rate,lower weight loss rate and a*value.Different concentrations of 2,4-epibrassinolide could effectively inhibit weight loss of daylily,0.5 mg/L 2,4-epibrassinolide had the best inhibitory effect,and maintained higher good flower rate and color.2.To get the better preservation method,daylily was treated by nano-packaging,10g/L chitosan and 0.5 mg/L 2,4-epibrassinolide with the indexes of good flower rate,weight loss rate,a*value,chlorophyll content,respiration rate and the relative electrolyte leakage.It was found that there was no significant difference(P>0.05)of nano-packaging and 0.5 mg/L 2,4-epibrassinolide treatment on inhibiting decrease of good flower rate,chlorophyll degradation and a*value increase,but they were better than 10 g/L chitosan treatment.0.5 mg/L 2,4-epibrassinolide treatment was better than nano-packaging and 10 g/L chitosan treatment on reducing weight loss,respiration rate and maintaining cell membrane integrity.Among the three methods,the additional cost of 0.5 mg/L 2,4-epibrassinolide was the lowest,only was 4.3%of nano-packaging and 5.6%of 10 g/L chitosan.By comprehensively consideration,0.5 mg/L 2,4-epibrassinolide treatment was the best preservation method.3.To explore the preservation mechanism,daylily was sprayed with 0.5 mg/L 2,4-epibrassinolide solution to research the effects of 2,4-epibrassinolide on the reactive oxygen metabolism and endogenous hormones content of daylily.It was found that 2,4-epibrassinolide could delay the peak time of SOD activity,CAT activity and POD activity,improve antioxidant enzymes activity,and effectively eliminate H2O2 to inhibit accumulation of MDA and increase of relative electrolyte leakage,keep cell membrane integrity of daylily.During storage,2,4-epibrassinolide had no significant effect on indole-3-acetic acid content,but maintained higher gibberellic acid and zeatin riboside content,inhibit accumulation of abscisic acid to delay the blooming and senescence of daylily.