Abstract
The persistence of gibberellin A3 on plant surfaces was examined using fruit of 'Marsh' seedless grapefruit (Citrus paradisi Macf.) and an inert glass model system. 14C-gibberellin A3 was applied to surfaces in aqueous treatment solutions or in waxing solutions. Dried-out treatment residues were removed by washing and analyzed for total and GA3-like radioactivity. Gibberellin A3 persisted without significant loss for at least 7 d in aqueous treatment solutions (pH 4.0 or 6.2) but was less persistent in the pH 10.4 waxing solution (t1/2=7 d). Loss of total peel surface radioactivity was fast during the first 3 days, slowing down afterwards. After 14 days 73% of the initial radioactivity could still be recovered from fruit peel surface and 70% of the recovered radioactivity was still in the form of gibberellin A3. Gibberellin A3 was somewhat more persistent in residues from pH 4 than pH 7 treatment solutions. Light had a slight enhancing effect on gibberellin A3 decomposition on fruit peel under growth chamber conditions. After 12 d at 100% relative humidity, 88% of the radioactivity on glass surfaces was still in the form of gibberellin A3, as against 45% at a relative humidity of 50%. Simulated field conditions, combining daily fluctuations in light, temperature and relative humidity, markedly enhanced gibberellin A3 decomposition on glass surfaces (t1/2=2 d). Gibberellin A3 was very persistent (90% after 9 d) in the waxing residues on fruit peel surface.
Original language | English |
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Pages (from-to) | 215-226 |
Number of pages | 12 |
Journal | Plant Growth Regulation |
Volume | 9 |
Issue number | 3 |
DOIs | |
State | Published - Aug 1990 |
Keywords
- Citrus paradisi
- degradation
- fruit surface
- gibberellin A
- uptake