Fig. 1: Tips of ‘Jingyanjing’ and its autotetraploid.

Normal growing tips of (a) ‘Jingyanjing’ (2×), its (b) autotetraploid (4×), and creased growth tip of (c) 4×. Red arrows point out the parts shown in their longitudinal sections in the row below. The anatomical structures of (d) 2× and (e) 4× were not significantly different. f Abscission zone clearly appeared in the section of the 4× tip with ceased growth