Role of ethylene in senescence of pollinated and unpollinated Campanula medium flowers

Abstract

The vase life of cut Campanula medium flowers in relation to ethylene production and its sensitivity to ethylene was investigated. Senescence of flowers was accelerated by exposure to ethylene at 2 μ1 · liter-1 for 48 hr, but not at 10 μ1 · liter-1 for 16 hr. Pollination markedly accelerated petal senescence of the cut flowers, but not by crushing the stigma or removing the stigma and style. Unpollinated flowers did not produce ethylene with flower senescence, whereas pollination markedly accelerated the climacteric increase in ethylene production from flowers, petals and pistil. Treatment with silver thiosulphate (STS), an ethylene action inhibitor, did not extend the vase life of unpollinated flowers, but markedly extended that of pollinated flowers. These results indicate that ethylene is involved in the senescence of pollinated flowers, but to a small degree in unpollinated flowers.