Endogenous hormone concentrations and bud-break response to exogenous benzyl adenine in shoots of apple trees with two growth habits grown on three rootstocks

摘要: SummaryScions from two siblings of a ‘Goldspur Delicious’ × ‘Redspur cross were budded to three rootstocks with different levels vigour [M.9, M.7, and Malus domestica ‘Antanovka’ seedling] planted in the field 1997. The scions had contrasting growth habits: one narrow crotch angles, numerous short branches an upright (UN) canopy; other wide few branches, spreading round (SR) canopy. Shoot tips collected at time bud-break April 2004 analysed for auxin (AUX), cytokinins (CK), abscisic acid (ABA) determine relationships between scion habit, size-controlling rootstock, shoot tip hormone concentrations. Although not statistically different, UN habit numerically higher AUX, lower ABA, equivalent CK as SR habit. These differences resulted AUX:CK ratios (ACR). It is possible that ACR contributed which h...