Morphological and morphometric analysis of Nekemias arborea and Ampelopsis aconitifolia (Vitaceae)

Leaf morphology in angiosperms is not constrained by the leaf’s important function of providing energy through photosynthetic reactions. In just one family, Vitaceae, it is easy to observe among it’s over 900 species, various leaf shapes and sizes even among closely related species as well as within individual species. Observation of these leaf forms within species can be used to determine, for example where a vine transitions from the juvenile state to the adult state as well as their relationship to the spatial and temporal patterning of inflorescence initiation. Analysis of two species within the Ampelopsis clade, one that retained ancestral leaf characters, Nekemias arborea, was compared with a species containing derived leaf characters, Ampelopsis aconitifolia, so that leaf shape relationships between members of the grape family could be assessed. Knowledge about the members of the Ampelopsis clade can help to reveal a better understanding of the development of the very important commercial species, Vitis vinifera (grape). Leaf development along the vines of each species was tracked to draw comparisons and divergences in leaf shape. Structures along the vine, such as tendrils and axillary buds, were also noted to establish a vine pattern and to help determine whether a correlation exists between these traits and leaf shape changes. Scanning electron microscopy was used to observe leaf initiation and shape elaboration from the shoot apical meristem. Landmarks on mature leaves were established using vein and dissection patterns and were statistically analyzed. Morphometric analysis using Elliptic Fourier Descriptors (EFD) was performed to establish relationships in leaf form between two species of within Vitaceae