Concentration of 1-methylcyclopropene and the duration of its application affect anti-ethylene protection in Phalaenopsis

Moth orchids (Phalaenopsis spp.) have become the world's most important potted flower crop. Flowers of Phalaenopsis are sensitive to ethylene, and 1-methylcyclopropene (1-MCP) pretreatment enables flowers to withstand ethylene stress. In this study, we investigated effects of 1-MCP concentration and duration of 1-MCP treatment on the protective effect in Phalaenopsis flowers. Pretreating potted Phalaenopsis amabilis with a 1-MCP concentration of as low as 0.005 mu L L-1 reduced the flower wilting percentage, indicating that as long as there is 1-MCP protection, the rapid wilting of flowers caused by ethylene can be delayed. However, in order to achieve absolute protection, the minimum concentration required was 0.1 mu L L-1. Pretreatment with 0.1 mu L L-1 1-MCP for 12 h gave Phalaenopsis plants absolute protection such that the flowers were unaffected even when exposed to artificially high ethylene concentrations of up to 20 mu L L-1. The duration of 1-MCP pretreatment could substantially be reduced. A 0.5-h treatment was sufficient when the concentration of 1-MCP was increased to 0.2 mu l L-1. The results obtained above were then further confirmed on seven commercial cultivars, where 0.1 mu L L-1 1-MCP treatment for 1 h was sufficient to achieve absolute protection against ethylene damage. (C) 2013 Elsevier B.V. All rights reserved.