Document: ANN-3-29-9

Phenotypic plasticity in Smilacina stellata from three habitats: Responses to light manipulations from a developmental perspective.

STORK, A.W.*

University of New Hampshire, Durham, NH 03824 USA ¹

Abstract:
Phenotypic plasticity is an important adaptation for plants that live in variable environments. For plants that preform their organs, past developmental events may particularly constrain plasticity. In Smilacina stellata, tissues form under late season light levels but plants emerge the following growing season under different, early season light levels. To address if S. stellata can respond to the light environment of emerging plants, I manipulated light levels for open fen (OF), forested fen (FF), and floodplain (FP) populations. Plants from all habitats showed reduced specific leaf weight (SLW) in response to shade treatments but FP plants response was twice, and OF plants was four times greater than the response of FF plants. Plants also varied in dark respiration responses: FF plants showed no response, FP plants showed minimal response, and OF treatment plants showed a significant decrease in dark respiration. To determine if these habitat-level differences would persist under common conditions, experiments were conducted on plants grown under greenhouse conditions. Shade treatment plants showed a significant reduction in SLW (25 g m ^-2 compared to 40 g m ^-2) but did not show a significant habitat effect. Plants did not show significant treatment or habitat effects for dark respiration. The field and greenhouse experiments show that S. stellata, even though it preforms its tissues under previous environments, can respond to the light levels of emerging plants. Plants do not vary by habitat in their ability to respond to early season light: Variation in plastic responses to light appears to be light-level dependent in S. stellata.

Keywords: phenotypic plasticity, light, specific leaf weight, dark respiration, habitat

This abstract is being presented at: 1:15 PM in session:
Oral Session #10: Light Relations in Plants.