2.4. Ethylene measurement
Immediately after ethylene treatment three flowers from each treatment were placed in a 1.8 L sealed glass bottle, and kept at 20 ± 2◦C for 48 h. Gas samples were taken after 24 and 48 h through head spaces via gas-tight syringe and injected into a gas chromatograph (GC Agilent 6890N) fitted with a capillary column and a flame ionization (FID) detector. The carrier gas was helium at 6.5 mL min−1, injection temperature was 180◦C and column temperature was 60◦C.