Treatment with 1-methylcyclopropene inhibits ethylene-induced bract abscission in potted bougainvillea (Bougainvillea spp.).

摘要

Senescence and abscission induced by exposure to ethylene are significant post-harvest problems in the bracts of bougainvillea (Bougainvillea spp.) 'Taipei Red'. Potted 'Taipei Red' bougainvillea plants at four different stages of bract development were treated with 100, 200, 400, or 800 nl l-1 1-methylcyclopropene (1-MCP) for 4 h in an hermetically-sealed plastic fumigation box and were then moved indoors to low-light conditions. Ethylene production was inhibited at the later stages of bract development (Stage 3 and Stage 4) when treated with all rates of 1-MCP, especially 800 nl l-1, which significantly prolonged bract longevity (by 8.2-9.2 d) compared to the untreated controls. Conversely, 1-MCP treatment did not significantly prolong the longevity of, or ethylene production in, bracts at Stage 1 or Stage 2 of development. Exposing flowers to 1.0 micro l l-1 ethylene for 24 h caused all bracts to abscise within 2 d. Treatment with 1-MCP at 800 nl l-1 immediately prior to exposure to 1.0 micro g micro l-1 ethylene largely prevented ethylene-induced flower abscission. In addition, 800 nl l-1 1-MCP significantly reduced the endogenous 1-aminocyclopropane-1-carboxylate (ACC) content and ACC oxidase activity, suggesting that the inhibition of ethylene production by 1-MCP resulted from reduced ethylene biosynthesis.