Studies On Plant Hormones In The Preservation And The Mechanisms Of Cut Lily Flowers

The thesis aimed to study systematicly the preservation affects of five plant hormones, namely ethylene, gibberellin, cytokinin, auxin and abscisic acid on cut lily flowers. It explored different physiological and biochemical reactions of flower preservation and cleared the main factors of senescence in this experiment. The results are as follows:(1) OT hybrids lily'Mantissa'were used in the study. The pulsing treatments (STS and spermidine) were carried out for 18 hours at room temperature. These results showed that the two ethylene inhibitors both have certain quality of products, which can increase fresh weight, reduce lipid peroxidation, and extend the vase life significantly. Cold storage on ethylene inhibitors improved sensitivity, with more significant effect on preservation than temperature.(2) Different concentration of GA₃, 6-BA, ABA, and IAA were selected on the 'Sorbonne' Lily after 18h pretreatment to observe the morphological and physiological indicators. Overall, the appropriate concentration of GA₃ treatment had good effect on preventing the leaves from yellowing, and extending the life in the vase to some extent, but it didn't affect the ornamental value significantly. The preservation of 6-BA pretreatments was unsatisfactory. The appropriate concentration of 6-BA treatment could extend cut vase life to some extent, but comparing with the basic formula which only adding sugar and fungicide, the difference was not significant. Appropriate concentration of GA₃ and 6-BA treatment could curb the production of MDA, and increase SOD activity to protect the integrity of cell membrane, but it inhibited the synthesis of anthocyanin significantly. ABA pretreatments had a duality that low concentration of ABA could improve the viewing quality of cut flowers, while high concentrations resulted in yellow leaves; lower concentrations of IAA treatment on the vase and other related indicators of quality were not significant; however, higher concentrations of IAA treatment inhibited the senescence.(3) Plant hormones in the process of senescence had different physiological effects, so were their preservation value.GA₃, 6-BA and ABA, were keeping a certain value, while the IAA was not suitable for the fresh cut flowers. It was mainly due to the appropriate concentrations of GA₃, 6-BA and ABA can prolong life of cut flowers, and delay of senescence, but high concentrations were inhibitory.