Dormancy in peach (Prunus persica) flower buds. VI. Effects of gibberellins and an acylcyclohexanedione (trinexapac-ethyl) on bud morphogenesis in field experiments with orchard trees and on cuttings

The effects of several gibberellins (GAs), exo-16,17-dihydro GA5, 2,2-dimethyl GA4, and GA3, and trinexapac-ethyl (an acylcyclohexanedione inhibitor of late-stage GA biosynthesis), were assessed for their effects on flower bud development during and after winter dormancy in peach (Prunus persica (L....

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Detalles Bibliográficos
Autores: Reinoso, Herminda, Luna, Virginia, Dauría, Carlos, Pharis, Richard P., Bottini, Ambrosio Ruben
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2002
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/161002
Acceso en línea:http://hdl.handle.net/11336/161002
Access Level:acceso abierto
Palabra clave:FLORAL BUD MORPHOGENESIS
GIBBERELLINS
PEACH
TRINEXAPAC-ETHYL
https://purl.org/becyt/ford/1.6
https://purl.org/becyt/ford/1
Descripción
Sumario:The effects of several gibberellins (GAs), exo-16,17-dihydro GA5, 2,2-dimethyl GA4, and GA3, and trinexapac-ethyl (an acylcyclohexanedione inhibitor of late-stage GA biosynthesis), were assessed for their effects on flower bud development during and after winter dormancy in peach (Prunus persica (L.) Batsch.) in three field trials and one experiment using cuttings. At late developmental stages, GA3 hastened floral bud development and shortened the time to anthesis, whereas early-stage applications of GA3 either had no effect or delayed floral bud development. In contrast, an exceptionally growth-active GA, 2,2-dimethyl GA4, promoted floral bud development (tested only on cuttings) across a range of application dates. However, it also induced a high percentage of bud abscission and remaining buds had a necrotic gynoecium and alterations in the androecium. Surprisingly, trinexapac-ethyl also promoted floral bud development, although it was not as effective as GA1. Trinexapac-ethyl-treated buds also showed morphological alterations and gynoecium necrosis. However, the best and most consistent treatment for enhancing floral bud development and hastening flower anthesis was 16,17-dihydro GA5. It stimulated floral bud development in up to 80% of the treated buds. Further, the promotive effect of 16,17-dihydro GA5 was maintained through to anthesis across three years of field experiments on intact trees, as well as with cuttings. Whether 16,17-dihydro GA5, a competitive inhibitor of the 3β-hydroxylation step in GA biosynthesis, acts per se, acts via a metabolite (such as 16,17-dihydro GA3), or acts by modifying endogenous GA metabolism is not yet known.