NEW APPLE SELECTIONS WITH INHERENTLY LOW ETHENE PRODUCTION

Some progeny of crosses between Gloster 69 and Fiesta, and between Gloster 69 and T30/24, were found to be very slow to produce ethene when stored in air at 4°C. In the former family, 42% of progeny took 4 weeks to reach an ethene production rate of 1μ1 kg^-1 h^-1, 33% took 5–17 weeks and the remainder had not exceeded this rate after 23 weeks.

Experiments were carried out to determine the cause of the low ethene production rates.
When apples from a cultivar with a low ethene production were exposed to propene, ethene production increased, suggesting that ethene receptors were still active.
Both ethene-forming-enzyme (EFE) activities and ACC concentrations also increased in response to propene treatment.
Cox’s Orange Pippin apples with a similar ethene production rate had a similar EFE activity and ACC concentration.
It was concluded that the delay to autocatalytic ethene production resulted not from a lowered activity of a single enzyme in the ethene biosynthetic pathway, or from a lack of ethene receptors, but from an enhancement of the inhibitory mechanism that prevents initiation of autocatalytic ethene production.

International Symposium on Pre- and Postharvest Physiology of Pome-fruit

J. Stow, F. Alston, S. Hatfield, P. Genge

https://doi.org/10.17660/ActaHortic.1993.326.8