Abstract Detail

Ecophysiology

Shapiro, Alex [1], Pena-Alfaro, Marisa [1], Farias, Lina [1], Hathaway, Ron [1], Heschel, M. Shane [1].

Cotyledon stomatal density differentiation and quantitative genetic analysis of seedling traits in Impatiens capensis ecotypes.

The biogeographic distribution of Impatiens capensis indicates that this species can inhabit a wide variety of moisture and light environments. As a result, physiological, morphological, and phenological plasticity in this species facilitates drought tolerance in regionally specific ecotypes. These ecotypes can respond to drought via changes in stomatal density, stomatal conductance, ABA production, and leaf growth. This study focuses on examining stomatal density and aperture as well as photosystem efficiency (PE) and height of Impatiens seedlings from both Colorado and Pennsylvania populations, and includes a quantitative genetic analysis of Impatiens lines from these ecotypes. Stomatal density and aperture of cotyledons were assessed using a Scanning Electron Microscope (SEM) and PE was measured with a fluorometer. It was found that geographic region was a predictor of stomatal density and height, but not of PE (marginally significant). Contrary to previous studies on adult Impatiens, this study showed that high stomatal densities in Colorado ecotypes indicate a drought escape strategy in seedlings that is not correlated to transpiration rates of parents. The quantitative genetic analysis of seedling physiological traits here provides an indication of the evolutionary potential of progeny traits across the geographic range of this species.

1 - Colorado College, Organismal Biology & Ecology, 14 E. Cache La Poudre St., Colorado Springs, CO, 80903, United States

Keywords:
Seedling
functional traits
ecotype.

Presentation Type: Poster
Session: P, Ecophysiology Posters
Location: Virtual/Virtual
Date: Tuesday, July 28th, 2020
Time: 5:00 PM Time and date to be determined
Number: PPE009
Abstract ID:315
Candidate for Awards:None