EXOGENOUS ABA APPLICATIONS DELAY DROUGHT-INDUCED WILTING BUT CAUSE LEAF AND FLOWER ABSCISSION IN FUCHSIA

Drought stress caused by infrequent or inadequate irrigation can have a negative impact on the postproduction quality and shelf life of ornamental plants.
Exogenous applications of s-ABA, the biologically active form of abscisic acid, can reduce transpiration and delay wilting in drought-stressed plants.
S-ABA applications allow plants to tolerate temporary periods of drought stress, and when irrigation is resumed these plants are often of marketable quality.
The effectiveness of these applications depends on concentration, application method and plant species.
In this study we evaluated the effect of s-ABA applications on fuchsia (Fuchsia × hybrid), a highly drought sensitive species.
Fuchsia × hybrida ‘Miniroos’ and ‘Lambada’ were sprayed with 0, 500 or 1000 mg•L^-1 s-ABA. Water was withheld and the time to wilt was determined based on visual observations.
Both the 500 and 1000 mg•L^-1 treatments resulted in a 1.6 or 1.0 day delay in wilting compared to the control plants (0 mg•L^-1) in ‘Miniroos’ and ‘Lambada’, respectively.
All drought stress plants regardless of s-ABA treatment had lower leaf, open flower and flower bud abscission.
S-ABA treatment of irrigated plants indicated that fuchsia ‘Lambada’ also had ABA-induced abscission of leaves and flowers.
Five mg•L^-1 BA + GA₄₊₇ prevented abscission in drought-stressed ‘Miniroos’ treated with 500 mg•L^-1 s-ABA, but was ineffective on the 1000 mg•L^-1 treatment.
Overall, s-ABA applications delayed drought-induced wilting in fuchsia, but shelf life was not extended due to the occurrence of phytotoxicity that could not be uniformly prevented with other PGR treatments.

International Conference on Quality Management in Supply Chains of Ornamentals QMSCO2012

N.L. Waterland, M.L. Jones

abscisic acid, bud abscission, PGRs, postproduction, senescence, shelf life

https://doi.org/10.17660/ActaHortic.2013.970.2