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Abstract Detail



Ecophysiology

Maricle, Brian [1], Gray, Miranda [2], Bryant, Johnny [2], Jensen, Amber [3], de la Cruz, Angel [2], Caudle, Keri [1], Olsen, Jacob [4], Baer, Sara [5], Knapp, Mary [6], Johnson, Loretta [7].

A possible mechanism for increased performance of a xeric adapted big bluestem (Andropogon gerardii) ecotype: nitrogen and chlorophyll content of leaves in reciprocal gardens across the Great Plains.

Big bluestem (Andropogon gerardii) is a dominant C4 grass in tallgrass prairie. With wide variation in precipitation across the tallgrass prairie (500-1200 mm per year from western Kansas to southern Illinois), it is expected genetic ecotypes might be present within the species, and these ecotypes might be adapted to water availability. To investigate a potential mechanism for drought tolerance, leaf nitrogen concentration (%N) were measured in eight replicate blocks of twelve plants, representing three ecotypes of A. gerardii (from Central Kansas, Eastern Kansas, and Illinois) at four reciprocal garden sites (Colby, Hays, and Manhattan, Kansas, and Carbondale, Illinois). Leaf chlorophyll content (based on SPAD measures) and photosynthesis were also measured in these plants. The xeric Central KS ecotype had higher %N and higher chlorophyll content across sites. The Central KS ecotype also had higher photosynthetic rates compared to other ecotypes. Site differences in photosynthesis correlated with available moisture; the highest photosynthesis rates were at the wettest site in Carbondale. When measured across all ecotypes, the garden site in Hays, KS was found to have the highest %N. However, the Carbondale, IL site had plants with the highest chlorophyll content. Increased nitrogen seems to confer an advantage to the xeric Central Kansas ecotype, especially at the drier planting sites. The Central Kansas ecotype maintained higher nitrogen concentration, manifested as increased chlorophyll content and higher photosynthesis rates compared to more mesic ecotypes from Eastern Kansas or Illinois. This research provides a mechanistic understanding of the observed ecotypic variation in physiological performance of big bluestem. Ultimately, this knowledge can help explain plant responses to decreasing precipitation in a dominant prairie species.

Broader Impacts:


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Related Links:
http://www.bluestemecotype.k-state.edu/bluestemecotype/Big_Bluestem_Ecotype_Project.html


1 - Fort Hays State University, Department of Biological Sciences, 600 Park St., Hays, KS, 67601-4099, USA
2 - Kansas State University, Division of Biology
3 - Nebraska Wesleyen University
4 - Fort Hays State University, Department of Biological Sciences
5 - Southern Illinois University, Department of Plant Biology
6 - Kansas State University, Department of Agronomy
7 - Kansas State University, Biology, Ackert Hall Rm 232, Manhattan, KS, 66506-4901, USA

Keywords:
Big bluestem
nitrogen
chlorophyll
photosynthesis
ecotypes
common gardens.

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: PEP002
Abstract ID:537
Candidate for Awards:None


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