Role of ethylene in acceleration of flower senescence by filament wounding in Portulaca hybrid

Factors accelerating flower senescence of Portulaca hybrid were investigated. Self‐and cross‐pollination, emasculation and removing of pistil significantly accelerated senescence. However, wounding of filaments was much more effective in accelerating flower senescence. Senescence was further accelerated by an increase in the number of wounded filaments, and ethylene production was also accelerated by wounding of filaments. Treatment with 0.1 µl 1−1 ethylene for 1 h significantly accelerated flower senescence, and the senescence of both the intact and filament‐wounded flowers was markedly delayed by exposure to norbornadiene (NBD), an inhibitor of ethylene action. The sensitivity to ethylene increased significantly within 1 h after wounding of filaments, but ethylene production did not. These results suggest that acceleration of flower senescence by wounding of filaments is caused by an increase in the sensitivity to ethylene and the subsequent production of ethylene.