The effect of flowering on adventitious root-formation

The rooting of cuttings from day-neutral tomato was not influenced by flower development, nor by SD or LD treatments of them or of the mother plants. In cuttings of the SD plant Perilla crispa flower initiation and development severely inhibited rooting. Leaves produced about 61 % of the roots, buds about 16 %, stems a small proportion. Together these organs were more effective than their summed separate effects. A supposed substance regulating adventitious root formation would need more than 2 days for transport from the leaves or buds. The physiological age of the cutting markedly affected rooting. The presence of buds during SD treatment may have changed auxin distribution, which became concentrated in the apical region and slightly promoted rooting there. Stems could induce flowering. Day length had no influence during rooting. Light on the base of the cutting inhibited root formation. In the LD plant red clover, flower initiation inhibited rooting of cuttings.

In both SD and LD plants, auxin distribution during flower initiation and development must cause antagonism between adventitious root formation and flowering. This did not apply to day-neutral plants with a vegetative terminal bud, but perhaps to those with a terminal flower bud.