Ethylene Co-ordinates Petal Abscission in Red Raspberry (Rubus idaeus L.) Flowers

The time-course of flower development of Rubus idaeus L. cv. Glen Clova was studied on detached buds opened in the laboratory. After sepal and petal opening petal abscission occurred with the petals from an individual flower being shed over 3-4 h. Abscission was accompanied by a peak in ethylene production. Treatment of flowers with aminoethoxyvinylglycine eliminated the peak in ethylene production but did not prevent petal abscission. However, petal loss was much slower, taking place over a period of days rather than hours. Abscission was more effectively retarded by silver thiosulphate. Exogenous ethylene accelerated the rate of petal abscission and senescence. The increase in ethylene production coincident with petal abscission appears to accelerate and co-ordinate the shedding of the separate petals on an individual flower. If ethylene is important in the induction of abscission it would appear that the low rate of production sustained in the presence of aminoethoxyvinylglycine must be sufficient. Copyright 1993, 1999 Academic Press