The effect of chemical structure on the antagonism by cyclopropenes of ethylene responses in banana

The compounds, cyclopropene, 1-methylcyclopropene, 3-methylcyclopropene, 1, 3-dimethylcyclopropene, 3,3-dimethylcyclopropene, 1,3,3-trimethylcycloprope ne, 3-methyl-3-vinylcyclopropene, and 3-methyl-3-ethynylcyclopropene, and 1 ,2-dimethylcyclopropene were tested as antagonists to the ethylene receptor in bananas. All of the compounds inactivated the receptor and the bananas did not respond to ethylene even at 1000 nL L-1. Large differences were fou nd in the concentration required (0.7-20,000 nL L-1 for 24h) to inactivate the receptor and in the duration of inactivation (3-12 days at 24C dependin g on the compound). After this time the bananas responded to ethylene and a ppeared to ripen normally.