EFFECTS OF ETHEPHON, ITS NONETHYLENE-GENERATING ANALOG ETHYLPHOSPHONIC ACID, AND PHOSPHORUS-ACID IN ASEPTIC CULTURE OF ORCHID SEEDLINGS

Citation
R. Ernst et al., EFFECTS OF ETHEPHON, ITS NONETHYLENE-GENERATING ANALOG ETHYLPHOSPHONIC ACID, AND PHOSPHORUS-ACID IN ASEPTIC CULTURE OF ORCHID SEEDLINGS, American journal of botany, 79(3), 1992, pp. 275-278
Citations number
23
Language
INGLESE
art.tipo
Article
Journal title
ISSN journal
0002-9122
Volume
79
Issue
3
Year of publication
1992
Pages
275 - 278
Database
ISI
SICI code
0002-9122(1992)79:3<275:EOEINA>2.0.ZU;2-8
Abstract
Seeds of Cattleya aurantiaca (Orchidaceae) were germinated and grown a septically on Knudson C medium containing 2.5, 5, 10, 20, and 50 mg l- 1 of 2-chloroethylphosphonic acid (Ethephon), ethylphosphonic acid, or the inorganic acid moiety of both, phosphorous (phosphonic) acid. 2-C hloroethylphosphonic acid, an ethylene precursor, reduced leaf length at 5-50 mg l-1 proportional to increasing concentrations. Seedlings pr oduced fewer leaves within the range of 20-50 mg l-1 Ethephon compared to lower concentrations (2.5-10 mg l-1). Germination was not affected adversely. Cultures containing the homologous, but not ethylene-gener ating ethylphosphonic acid in the same concentrations brought about si milar but generally less severe reductions in leaf length and number. Phosphorous acid at the same concentration levels did not reduce the n umber and length of leaves. Our observation suggests that the intact o rganic phosphonates contribute to the inhibition of leaf growth caused by ethylene, which is released slowly from Ethephon in the culture me dium and/or plant tissue, following uptake.