Quantitative description of the process of architecture formation inViburnum dilatatum andV. wrightii (Caprifoliaceae)

Abstract

Process of architecture formation was comparatively analyzed usingViburnum dilatatum andV. wrightii (Caprifoliaceae). In both species, orthotropic primary axes emerge from the basal parts of mother plants near the ground level. The primary axes grow vigorously in the first and the subsequent few years of their development. Later on, they decrease their elongation rates gradually and many axillary buds stay in dormancy. A few of the axillary buds emerge after several years' dormancy and elongate vigorously forming orthotropic secondary axes. inViburnum dilatatum, nearly 50% of the primary axes develop the secondary axes. The secondary axes elongate as vigorous as the primary axes. Furthermore, more than 20% of the secondary axes form the tertiary axes, and only 10% of the tertiary axes form the quarternary axes. In contrast, inViburnum wrightii only less than 25% of the primary axes form the secondary axes, and there is no tertiary or quarternary axis. The secondary axes of this species elongate less vigorously than the primary axes. As the result of those differences in the axis formation,Viburnum wrightii forms a simpler architecture thanV. dilatatum.