Abstract Detail

Ecophysiology

Caudle, Keri L. [1], Hilt, Christina [1], Smart, Cera [1], Kramer, Diedre [1], Cheema, Sana [1], Johnson, Loretta [2], Baer, Sara [3], Maricle, Brian [4].

Pigment variation among ecotypes of big bluestem (Andropogon gerardii) across a precipitation gradient.

Environmental conditions such as light, temperature, and water availability can affect plant pigments, but less is known regarding genetic influences on pigment content. Chlorophyll is active in light harvesting processes of photosynthesis whereas anthocyanins protect leaves against high-light stress. Big bluestem (Andropogon gerardii) is a dominant tallgrass species with several genetically-distinct ecotypes, each adapted for conditions in their native habitat. Three ecotypes as well as two cultivars of big bluestem were measured for anthocyanin and chlorophyll content at reciprocal common gardens across a precipitation gradient (500-1200 mm/yr) from Colby, Hays, and Manhattan, KS, to Carbondale, IL. There were significant differences among ecotypes for SPAD chlorophyll index and extractable chlorophyll, with the most drought-adapted ecotype having the most chlorophyll. There were also prominent differences among sites. Anthocyanin content was highest in big bluestem ecotypes grown at the most arid common garden site in Hays, and the highest SPAD chlorophyll indices were measured in big bluestem at the driest field sites in Hays and Colby. A combination of high anthocyanin and chlorophyll concentration appears to be an adaptation for life in dry conditions, both within a growing season and over longer term evolutionary history. Anthocyanins protect against high light, while chlorophylls increase light harvesting capacity. In contrast, big bluestem grown at more mesic common garden sites had lower pigment concentrations, suggesting different climate conditions (moisture, light) might shape plants differently regarding pigment variation. More pronounced differences between sites rather than ecotypes indicate the environment might be a stronger factor than genetics in determining pigment content.

Related Links:
Big Bluestem Ecotype Project

1 - Fort Hays State University, Department of Biological Sciences, 600 Park St., Hays, KS, 67601, USA
2 - Kansas State University, Biology, Ackert Hall Rm 232, Manhattan, KS, 66506-4901, USA
3 - Southern Illinois University, Department of Plant Biology, Life Science II, Mail Code 6509, Carbondale, IL, 62901, USA
4 - Fort Hays State University, Department Of Biological Sciences, 600 Park St., Hays, KS, 67601-4099, USA

Keywords:
big bluestem
ecotype
sand bluestem
anthocyanins
chlorophyll
Drought
water availability.

Presentation Type: Poster:Posters for Topics
Session: P
Location: Eyrie/Boise Centre
Date: Monday, July 28th, 2014
Time: 5:30 PM
Number: PEP004
Abstract ID:187
Candidate for Awards:Physiological Section Best poster presentation,Physiological Section Physiological Section Li-COR Prize