Measuring the rate of ethylene production

Two lobes of leaf tissue from the second most recently matured leaf were cut from each plant, sealed with a serum stopper in a 30-mL test tube, and incubated at 25 °C for 24 h. After 24 h, one mL of the gas inside the test tube was sampled and ethylene concentration was measured using a gas chromatograph (Buck Scientific, Model 310, Norwalk CT, USA) fitted with an alumina column with a flame ionization detector. Leaves were then dried and quantity of ethylene produced per gram of dried tissue and per incubation time was calculated.