EFFECT OF 1-METHYLCYCLOPROPENE AND METHYLENECYCLOPROPANE ON ETHYLENE BINDING AND ETHYLENE ACTION ON CUT CARNATIONS

1-Methylcyclopropene (1-MCP), formerly designated as Sis-X, has been s hown to be an effective inhibitor of ethylene responses in carnation f lowers in either the light or the dark. The binding appears to be to t he receptor and to be ''permanent''. A 6 h treatment at 2.5 nl l(-1) i s sufficient to protect against ethylene, and 0.5 nl l(-1) is sufficie nt if exposure is for 24 h. As carnation flowers age, a little higher concentration appears to be needed. Most of the natural increase in et hylene production during senescence is prevented by treatment with 1-M CP. A closely related compound, methylenecyclopropane shows ethylene a ctivity. A tritium labelled 1-MCP (60 mCi mmol(-1)) has been prepared. A higher specific activity is needed for more critical studies.