Geotropic and Morphological Alterations in Rice Seedlings caused by Plant Growth Regulators

Abstract

DURING some investigations into the effects of gamma-BHC on rice seeds a number of experiments were carried out to test whether BHC was behaving in a similar way to plant growth substances in producing abnormalities. These experiments were carried out because it was found that gamma-BHC inhibited root growth at low concentrations (for example, in aqueous solutions at 10⁻⁵ M, root growth was reduced to half that of the controls) and because of a recent suggestion by MacLagan¹ that some of the chlorinated hydrocarbons, including BHC, might behave in a similar way to auxins in plant tissue. It has now been found (unpublished work) that BHC does not behave as an auxin so far as rice seedlings are concerned. Nevertheless, during these experiments some results were obtained which may shed some light on current theories of geotropism and also on the effects that auxins have on morphogenesis.