A study of the growth of axillary buds in angiosperms : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Botany at Massey University
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A description of the growth of axillary buds in the period before bud break was made in a number of angiosperms. This entailed a study of the growth of buds at representative locations in a plant as well as at different stages in the plant's growth. A number of different patterns of axillary bud development were found to exist. A way of assessing the significance of the differences between patterns was found. This involved comparing the observations with the theoretical possibilities which existed. A loose classification of the patterns was then constructed using the theoretical possibilities as a basis. An analysis of the data for each species was carried out to see if a cause for the cessation of bud growth could be determined. This analysis pointed towards the existence, in a large number of species, of a correlation between growth in an axillary bud and growth in surrounding tissues, particularly the expanding subtending leaf. One species - Salix fragilis - was chosen as the subject for a particularly detailed analysis. A clear correlation was established between growth in an axillary bud and growth in the stem in the immediate vicinity of the bud as well as in its subtending leaf. A number of experiments aimed at finding out the nature of a correlation between growth in an axillary bud and its subtending leaf were carried out with this species. These demonstrated that removal of a subtending leaf at an early stage in its growth had a significant depressing effect on axillary bud growth. This depressing effect was most pronounced during the period of most rapid growth in the axillary bud and its subtending leaf. The data from the general survey of over thirty plant species and the experiments with Salix jragilis seem to support the notion that the process of axillary bud growth - as opposed to that of lateral shoot outgrowth from axillary buds - is affected more by conditions within the growing stem than by influences exerted by the stem apex.
Salix fragilis, Angiosperms, Axillary buds, Bud grwoth