List of the primers used in this study.

a The relative positions of the primers on the sequence of T44.4 are shown in Figs 1 and 2.A shoot of C44.4.146 and non-transformed 'Gala Galaxy' control plants, which simultaneously experienced in vitro culturing were then micrografted on 'Golden Delicious' seedlings following the procedure described by Joshi [57] and acclimatized to greenhouse conditions. This latter genotype is described in this manuscript as “'Gala Galaxy' in vitro”. DNA of the micrografted C44.4.146 plant, its motherline T44.4, Malus ×robusta 5 and 'Gala Galaxy' in vitro, was retested by PCR for absence of sequences beyond the left border, presence of FB_MR5 and absence of the selectable marker genes NptII and Flp using the corresponding primers (Figs 2 and 3).List of the primers used in this study.