WALKER, JASON C.1* and KATHERINE C. LARSON2. 1University of Central Arkansas, Department of Biology, Conway, AR 72035; 2University of Central Arkansas, Department of Biology, Conway, AR 72035. - Morphological plasticity in two types of Lonicera in response to light availability.
Abstract:-Japanese honeysuckle (Lonicera japonica) is an
invasive vine that is currently outcompeting its native congener coral
honeysuckle (Lonicera sempervirens). Some studies have
demonstrated that in response to herbivory and CO2
enhancement, L. japonica was more plastic than its native
congener. L. japonica has also been shown to be more
morphologically plastic than L. sempervirens in response to
climbing supports. The goal of this study was to compare morphological
plasticity of L. japonica and L. sempervirens in
response to light. My hypothesis was that L. japonica would
show greater plasticity than would the L. sempervirens. The
study included seventy-two honeysuckle plants that were grown in three
separate light treatments-30% neutral shade, 70% neutral shade, and
70% green film. The two neutral shade treatments were used to measure
the effect of light intensity; and the two 70% shade cloths, neutral
and green, were used to measure the effects of light wavelength. Four
different morphological variables were measured on each plant:
internode length (cm) on the primary shoot, internode length (cm) of
the lateral shoots, branching index , and the lateral angles (angle of
the first lateral in relation to primary shoot). I predict, based on
past evidence, that L. japonica will show stronger phenotypic
plasticity in conjunction with all four morphological variables.
Key words: Caprifoliaceae, honeysuckle, invasive species, light availability, Lonicera, phenotypic plasticity, plant foraging