| Abstract Detail
Ecophysiology Caudle, Keri [1], Johnson, Loretta [2], Baer, Sara [3], Maricle, Brian [1]. Influence of precipitation on trichome densities in big bluestem (Andropogon gerardii) ecotypes in Great Plains reciprocal gardens. Big bluestem (Andropogon gerardii) is native to the tallgrass prairie, which is becoming increasingly susceptible to extended drought. The gradient of rainfall received across the central US grassland presumably has given rise to ecotypes of big bluestem adapted to different precipitation regimes. Trichomes (epidermal hairs) are often a water conservation strategy in plants to reduce incoming radiation or increase the boundary layer. This study examined variation in trichome density among five A. gerardii ecotypes (from Central Kansas, Eastern Kansas, Illinois, and two cultivars of Kaw and Sand bluestem) reciprocally grown across a precipitation gradient in common gardens at Colby (505 mm/yr), Hays (582 mm/yr), and Manhattan, KS (872 mm/yr), and Carbondale, IL (1167 mm/yr). Trichome density was calculated on the adaxial surface of leaf blades. Trichome density increased with increasing aridity of sites. The mesic-adapted ecotype from Illinois often responded to decreased precipitation to a greater extent compared to xeric-adapted ecotypes, with increased trichome density in the most arid site in Colby, KS. The most xeric-adapted ecotype from Central Kansas had the greatest number of trichomes at the other dry site in Hays, KS. This indicates a common response to precipitation in genetically different ecotypes. The Eastern Kansas ecotype and the Kaw cultivar exhibited greater trichome density with increasing aridity of sites, but to a lesser extent than the Central Kansas or Illinois ecotypes. By contrast, the Sand bluestem cultivar did not form more trichomes with decreased precipitation, likely due to greater amounts of wax on leaves. An ecotype-specific response to precipitation suggests different morphological responses to drought. Broader Impacts:
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1 - Fort Hays State University, Department of Biological Sciences, 600 Park St., Hays, KS, 67601-4099, USA 2 - Kansas State University, Biology, Ackert Hall Rm 232, Manhattan, KS, 66506-4901, USA 3 - Southern Illinois University, Department of Plant Biology, 1220 Lincoln Drive, Carbondale, IL, 62901, United States
Keywords: Big bluestem sand bluestem ecotypes trichomes.
Presentation Type: Poster:Posters for Topics Session: P Location: Grand Salon A - D/Riverside Hilton Date: Monday, July 29th, 2013 Time: 5:30 PM Number: PEP003 Abstract ID:534 Candidate for Awards:None |