The influence of abscisic acid in the control of apical dominance in dwarf bean plants Phaseous Vulgaris L.:A dissertation submitted in partial fulfilment of the requirements for the Degree of Bachelor of Agricultural Science with Honours in the University of Canterbury

Abstract

Throughout the plant kingdom, in response to increasing complexity of plants, methods of control and correlation of the individual tissues have developed to produce an integrated organism, capable of adapting to a changing environment. Apical dominance, which is the complete or partial inhibition of lateral shoots in the presence of a dominant shoot, is only one example of a correlative growth phenomena in plants. In most higher plants, the angiosperms, the gymnosperms, the pteridophytes, the bryophytes, and even some algae, the apical shoot usually has some form of dominance over the lateral shoots and organs, (Phillips, 1969). Some shoots are more sensitive to apical dominance than others, and as a result, selective branching and orientation of plant organs takes place. Snow (1931), demonstrated this phenomenon using two cotyledonary buds of a young pea seedling. By weakening one bud through shading or injury, the other shoot assumed a dominant role completely inhibiting the weaker shoot.