The Pattern Of Endogenous Ethylene Production Of 'Luo Yang Hong' Tree-peony Cut Flowers And Its Responses To Exogenous Ethylene During Postharvest Senescence

It is practical significance in developing the traditional famous flower tree-peony into cut flower with Chinese characteristic. Up to now, there are few reports about the senescence mechanism of tree-peony cut flowers, especially the pattern of endogenous ethylene production of tree-peony cut flowers and its responses to exogenous ethylene during postharvest senescence.'Luo Yang Hong', one of the cut flower cultivars of tree-peony, was taken as the material. The ethylene production was measured to ascertain the ethylene metabolic traits and the threshold of the ethylene climactery during the vasing process. After treated by the ethylene and the ethylene inhibitor 1 - MCP, the postharvest behaviors during the florescence, the ethylene production, the variation of ACC content, the activity of ACS (ACC synthase) and ACO (ACC oxidase) were analyzed to investigate the pattern of endogenous ethylene production of 'Luo Yang Hong' tree-peony cut flowers and its responses to exogenous ethylene during postharvest senescence. The main experimental results are as follows:1) The endogenesis ethylene production of 'Luo Yang Hong' during natural florescence was like climactic type. In the vasing process, the threshold of ethylene climacteric is about 0.0008ng/L, in other words, the threshold happens when the ethylene production is 0.04 nl/g·h, the flower is at the 3rd stage of opening.2) After treated by the ethylene and the ethylene inhibitor 1 - MCP around the threshold, the cut flowers of 'Luo Yang Hong' at the 2nd stage with the 1 - MCP treatment were much better than at the 3rd stage with the ethylene and 1 - MCP treatment through evaluating the ethylene production, the postharvest behaviors and the longevity.3) When probinging the tree-peony cut flower's responses to exogenous ethylene, it was found that the activity of ACS was increased some extent of 'Luo Yang Hong' at the 2nd stage treated by the ethylene inhibitor. But the ACC content dropped because the ACC changed into ethylene. The activity of ACO constantly dropped during the tree-peony cut flower opening and senescence. It waspresumed that the drop of the activity of ACO maybe the reason why the ethylene climacteric was delayed and the longevity was prolonged of 'Luo Yang Hong' at the 2nd stage treated by the ethylene inhibitor.