Journal of the American Society for Horticultural Science · 1976 · 14 citations · 8 references
Life SciencesPlant BiologyPlant SciencesPlant BiochemistryPlant Hormone BiologyPlant PhysiologyAbscisic Acid BiologyAuxin BiologyBud DormancyGibberellin BiologyPlant Hormone SignalingAbscisic Acid Regulation Of Bud DormancyDormant StagesGibberellic Acid TreatmentGibberellin ApplicationGibberellin EffectsGibberellin Regulation Of Shoot ElongationHormonal Regulation Of Shoot GrowthSummer Dormancy
Abstract Shoots on interstem-dwarfed apple ( Malus domestica Borkh.) trees ceased growing earlier and showed a stronger tendency towards becoming summer dormant than did corresponding shoots on vigorous trees. Substances similar to gibberellic acid (GA3) and abscisic acid (ABA) were extracted from 1-year-old stems at 7 stages during the growing season using the centrifugation technique. ABA-like activity was higher in stems from dwarf than vigorous trees at full bloom, and remained higher until after the onset of summer dormancy. GA-like activity also was significantly higher in dwarf tree stems at the tight flower cluster stage. Injection experiments demonstrated that increasing ABA concn decreased terminal elongation in a linear manner. ABA-induced inhibition was reduced in direct proportion to the concn of GA3 in the injected solution.
8