2.2. 1-MCP and ethylene treatments
Cut rose stems were placed in 200 L glass chambers and treated with desirable concentrations of 1-MCP (0, 0.5 and 1 L L−1) for 12 h. After adding some drops of water to commercial powdered formulation Smart Fresh TM (AgroFresh, USA), immediately the chambers’ lids were tightly sealed according to Buanong et al.(2005). 1-MCP treated and non treated flowers were aerated for an hour and thereafter were exposed to 8 L L−1 ethylene concentration for 6 h. Control cut flowers were placed in identical glass chamber without receiving 1-MCP or ethylene treatment. A100 ml solution of 1 M NaOH was also placed inside the chambers to maintain low CO2 concentrations from respiration during both treatments. The experiment was conducted at 20 ± 2◦C, 60–65%RH, and a 12/12 h light/dark photo period at an illumination of 15 mol m−2 s−1. After ethylene treatment, rose petals were immediately collected, frozen in liquid nitrogen and stored at −80◦C fo rRNA extraction.