| Abstract: | The pattern of root and shoot growth of Perilla frutescens L.Britt. was studied in plants growing either in norally inductivephotoperiods or in non-inductive photoperiods. By the 20th dayof inductive treatment, that is at least 5 d before the firstflowers were pollinated, the rate of dry matter accumulationin the roots was slower in induced than in non-induced plants.The roots of induced plants had both a smaller fresh weightand dry weight per unit length. The rate of root elongationalso became slower in induced plants than in non-induced plants.The frequency of branching was greater in roots of induced plants.Plants exposed to inductive photoperiods showed precocious developmentof axillary buds on the shoot, and a reduction in the rate ofstem elongation. It is suggested that these changes in the shootreflect a decrease in the auxin status of the shoot, which mayin turn be responsible for the decreased rate of root growthin the induced plants. |
