Effects of Exogenous 6-BA on Preservation and Physiological Metabolism of Hemerocallis citrina Baroni
In order to investigate the effect of 6-BA on storage and physiological metabolism of daylily,Datong Daylily was used as experimental material and was sprayed with different concentrations of 6-BA(5,10 and 15 mg·L-1)before storage.Indicator including the good flower rate,weight loss rate,chlorophyll content and respiratory intensity of Datong Daylily were investigated at certain time interval during the storage to select the optimal 6-BA concentration.Moreover,physiological indicators including the relative conductivity,malondialdehyde,H2O2,SOD and POD were investigated.The mechanism of 6-BA affecting the physiological metabolism of daylily was clarified through correlation analysis.The results showed that exogenous 6-BA treatment could reduce the respiratory rate and weight loss rate of daylily,maintain a higher good flower rate,and inhibit the degradation of chlorophyll.Moreover,10 mg·L-1 6-BA treatment has a better preservation effect than other treatments.Compared with the control,application of 10 mg·L-1 6-BA could decrease the relative conductivity,malondialdehyde and H2O2 contents,and increase the activities of SOD and POD enzymes.Correlation analysis showed that the accumulation of H2O2 induced the production of malondialdehyde during the storage of daylily,leading to the increase of cell membrane permeability and relative conductivity.The antioxidant enzymes SOD and POD effectively inhibited the increase of H2O2 content,which reduced the damage of H2O2 to daylily.After 6-BA treatment,the activity of antioxidant enzymes SOD and POD increased,which reduced the accumulation of H2O2,and thus decreased the malondialdehyde content and relative conductivity of daylily during storage.Therefore,exogenous 6-BA treatment could delay the aging of postharvest daylily and achieve certain preservation effect.This study can provide theoretical basis for the development of storage technology and preservation mechanism of daylily.