Anatomy of flower differentiation and abortion, in relation to the growth and development of hybrid tea-rose seedlings

Abstract

From germination until anthesis or flower bud abortion, seedlings from ‘Sonia’ × ‘Hadley’ were grown in both a greenhouse (full daylight, 20° C) and a growth room (8 Wm −2, 8 h, 20°C) of the IVT-phytotron. Plastochron was an external indication of the stage of flower differentiation. Flower differentiation in flowering and aborting seedlings ran parallel up to petal-segregation. Flower differentiation in aborting seedlings did not proceed beyond stamen formation. Early abortion, which also caused absence of the upper leaf, occurred without, later abortion with, an abscission zone in the flowerstalk.