Effect of orchard and postharvest application of daminozide on ethylene synthesis by apple fruit.
Knee, M.; Looney, N. E.;
Journal of Plant Growth Regulation Year: 1990 Vol: 9 Issue: 3 Pages: 175-179 Ref: 18 ref.
1990
บทคัดย่อ
The effects of daminozide on ethylene synthesis by apple fruits were investigated. The objective was to determine the effects of postharvest applications as compared with the standard application of daminozide in the orchard. Immersion of fruits in a solution containing 4.25 g a.i./litre for 5 min delayed the rise in ethylene production in individual cv. Cox's Orange Pippin apples at 15 deg C by about 2 days, whereas orchard application of 0.85 g/litre caused delays of about 3 days. Both modes of application depressed the maximal rate of ethylene production attained by ripe apples by about 30%. Daminozide did not affect the stimulation of respiration by ethylene treatment of Gloster apples, but it delayed the increase in ethylene synthesis. Daminozide applied immediately after harvest delayed the rise in ethylene synthesis in Golden Delicious held at 15 deg , but it was less effective when applied 48 h after harvest or when apples were held at 5 deg . Exposure to ethylene at 1-2 micro l/litre for 48 h was less effective in promoting the rise in ethylene in daminozide-treated Cox and Gloster apples than in untreated fruits. High (100-1000 micro l/litre) concentrations of ethylene more or less overcame the daminozide effect. Apples absorbed about 40% of surface-applied [14C]daminozide in 48 h, but >90% of the radioactivity in the fruit was recovered from the peel and outer 1 cm of the cortex. Daminozide was partly converted to carbon dioxide and other metabolites.