Effect of 1-MCP on blooming Phalaenopsis orchids against ethylene
Yin-Tung Wang
Texas A&M Univ. System, Agricultural Research and Extension, 2415 East Highway 83, Weslaco, TX, USA, 78596
2002
บทคัดย่อ
The organic gas 1-methylcyclopropene (1-MCP) was shown previously to protect exised orchid flowers from being injured by ethylene up to 10 μL/L. However, with charcoal, other organic materials, and water in the potting media, it was not known if MCP would protedt the orchid flowers on intact plants. In several experiments, blooming Phalaenopsis plants were first fumigated with 1-MCP for 6 h, exposed to ethylene for 24h, and then evaluated under continuous 10 μmo.lm-2.s-1 PPF at 23-25 0C. in all experiments, unprotected flowers wilted within 2 d of their exposure to ethhlene. 1-MCP at 0.1 to 1.0 μL/ L offered equal protection (flowers lasting 27 to 34 d) against ethylene. In another experiment, flowers treated with 0.4 μL/L 1-MCP and then exposed to ethylene after 7 or 14 d wilted within 4.5 d after ethylene treatment. However, plant that were re-treated with 1-MCP after two weeks and then exposed to ethylene lasted as long as the control flowers (50 d). ln a third experiment, 0.5 or 1.0 μL/L 1-MCP protected flowers against ethylene for 6 d but not 14 d. Therefore, the protection offered by treating flowers with 1-MCP up to 1.0 μL/L was transient. It appears that unopened buds at time of 1-MCP treatment remained sensitive to ethylene after treatment. In the fourth experiment using excised flowers with no exogenous ethylene exposure, all untreated control flowers wilted within 2-3m d whether emasculated or not. Emasculated flowers pulsed for 24 h with 0.5 mM AOA lasted for 6 d, while the non-emasculated flowers treated similarly lasted for 9 d. Emasculated and non-emasculated flowers fumigated with 1 μL/L 1-MCP for 6 h lasted 9 and 13 d, respectively. 1-MCP apparently was more effedtive than AOA in supressing ethylene synthesis in flower tissues. In the last experiment, pollinated, emasculated, and intact flowers lasted 3, 10, and 21 d, respectively.