Abstract Detail

Physiology & Ecophysiology

Varvel, Nick A. [1], Hilt, Christina J. [1], Baer, Sara G. [2], Johnson, Loretta C. [3], Maricle, Brian R. [4].

Genetic and Environmental Influences on Stomates of Big Bluestem (Andropogon gerardii).

Big bluestem (Andropogon gerardii) is a dominant prairie grass that has wide distribution and several genetically distinct ecotypes within the species. Many of the ecotypic adaptations of big bluestem are related to water availability in the native environment. Epidermal pores on leaves, called stomates, facilitate photosynthetic gas exchange and regulate water loss from the plant. As such, stomatal size and density represent possible adaptations to conserve water. We hypothesized drought-tolerant ecotypes of big bluestem would have fewer or smaller stomates compared to more mesic ecotypes. Five ecotypes of big bluestem were planted in four common gardens from western Kansas to southern Illinois to determine genetic and environmental influences on stomates. We made epidermal imprints to measure stomatal size and density on tops and bottoms of leaves. Leaves were largely hypostomatous, with 187 stomates mm^-2 on the adaxial surface and 5.3 stomates mm^-2 on the abaxial surface. Genetics was a much more prominent influence than environment for stomatal size and density. The drought-tolerant Sand Bluestem had larger stomates on the bottoms of leaves, but a lower density compared to most other ecotypes. The most mesic ecotype from Illinois and the Kaw cultivar had the greatest density of stomates on the bottoms of leaves. Sand Bluestem had a greater density of stomates on the tops of leaves compared to all other ecotypes. There was no difference in size or density of stomates among sites, despite mean annual precipitation ranging from 505 to 1167 mm, illustrating the genetic underpinnings of stomates in big bluestem. There is a genetic predisposition for drought-tolerant ecotypes to have fewer stomates, illustrating an evolutionary adaptation to drought tolerance in an important prairie species.

1 - Fort Hays State University, Department of Biological Sciences, 600 Park St., Hays, Kansas, 67601, United States
2 - Southern Illinois University, Department of Plant Biology and Center for Ecology, Carbondale, IL, 62901, USA
3 - Kansas State University, Biology, Ackert Hall Rm 232, Manhattan, KS, 66506-4901, USA
4 - Fort Hays State University, Department Of Biological Sciences, 600 Park St., Hays, KS, 67601-4099, USA

Keywords:
none specified

Presentation Type: Poster
Session: P, Physiology & Ecophysiology
Location: Exhibit Hall/Omni Hotel
Date: Monday, June 26th, 2017
Time: 5:30 PM This poster will be presented at 5:30 pm. The Poster Session runs from 5:30 pm to 7:00 pm. Posters with odd poster numbers are presented at 5:30 pm, and posters with even poster numbers are presented at 6:15 pm.
Number: PPE001
Abstract ID:161
Candidate for Awards:None