Formation of fruits on rootless plants

Abstract

Fruits develop on tobacco, tomato, pea, and bean plants even though the roots are removed at the time of flowering and the formation of adventitious root primordia is prevented by periodic excision of the bases of the stems. Pea and bean fruit growth in the absence of roots is limited by the accelerated senescence of the foliage. Experiments with tomato shoots had to be concluded when the fruits were still enlarging since all the subtending stem had been removed. Tobacco fruits will reach maturity on stems without roots and will produce viable seed. Removal of roots from young bean plants results in a rapid and drastic inhibition of stem growth. In contrast, when roots are removed during flowering, pod growth is not severely inhibited until much later when the foliage has senesced. Seeds developing in the absence of roots contain well-differentiated embryo axes and cotyledons. They are smaller in size than those of the controls, an effect which can probably be explained by the reduced food supply available to them from the senescing foliage. The appreciable degree of fruit and seed development after root removal indicates that the developing fruits and seeds probably do not depend exclusively on roots for their supply of growth regulators.