AZ development at the base of X3177 pedicels. A, Development of AZ in central pedicels at 14 DAP (A1), 17 DAP (A2), and 21 DAP (A3), stained with acridine orange. The AZ did not develop in the course of these three dates. i, Invagination. B, Development of AZ in L1 pedicels at 14 DAP (B1), 17 DAP (B2), and 21 DAP (B3), stained with acridine orange. The development of an AZ, represented by layers of different colored cells, is clear at 21 DAP. C, Closeup view of the AZ in L1 pedicels at 17 DAP, stained with acridine orange. Arrows indicate the positions of dividing cells. D, Closeup views of the AZ in L1 pedicels at 21 DAP. D1, Pedicel section stained with acridine orange. The AZ is divided in two; the top section (fruitlet side) is composed of large stratified cells with lignified cell walls (li), and the bottom section (bourse side) is composed of smaller stratified cells with possible suberin deposition on the inner face of primary cell walls (su). D2, Scanning electron microscopy of AZ in L1 pedicels at 21 DAP. Cell wall and middle lamella degradation is observed in the separation layer. D3, Pedicel stained with toluidine blue. The stratified cells composing the AZ and the separation layer can be observed. The scale is represented by a bar at the bottom of each image.