Submitted to: Basic and Applied Ecology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/9/2003
Publication Date: 5/2/2004
Citation: Derner, J.D., Tischler, C.R., Polley, H.W., Johnson, H.B. 2004. Intergenerational above- and belowground responses of spring wheat (Triticum aestivum L.) to elevated CO2. Basic and Applied Ecology. 5:145-152. Interpretive Summary: Increasing atmospheric carbon dioxide concentration is a global change that will affect how crop plants grow in the future. While most experimental studies have evaluated how a single generation of a crop plant responds to this global change, little is known of how annual crop plants may respond to elevated carbon dioxide concentration for multiple generations. We evaluated the influence of elevated carbon dioxide on above- and belowground growth of spring wheat for three generations. Above- and belowground growth were enhanced similarly with elevated carbon dioxide in each generation. Greater growth enhancement was observed in the third than second generation when the wheat plants were young, but not when plants produced seed. Results indicate that increasing responsiveness of spring wheat to carbon dioxide results from greater seedling development in each subsequent generation. Continued response of wheat plants to elevated carbon dioxide across generations suggests that wheat will benefit from this global change.
Technical Abstract: We quantified intergenerational above- and belowground responses of two genotypes of semi-drawf, hard red, spring wheats Triticum aestivum L.) to elevated (700 umol mol**-1) CO2 in glasshouse experiments. These plants were progeny of seeds produced from previous generation plants grown at elevated CO2 under well-watered and high nutrient conditions. Our objective was to assess temporal changes in the relative enhancement (elevated/ambient) of above- and belowground plant growth at elevated CO2 across generations. Both genotypes responded similarly to CO2 enrichment. Relative enhancement occurred in both the second and third generations for both above- and belowground variables. Above- and belowground variables were enhanced by similar relative amounts at elevated CO2 within a generation at each harvest date. Relative enhancement of measured variables was generally greater in the third than second generation when plants were in the seedling or vegetative stage, but not when plants were reproductive. Additional research is needed to investigate physiological or other limitations of translating above- and belowground responses to CO2 in vegetative growth stages to reproductive performance. Intergenerational above- and belowground responses of this C3 annual plant to CO2 enrichment are not driven by genetic change (selection) that occurred between generations, but rather CO2-induced changes to subsequent seedling development in the next generation that continued through the generations studied here, suggesting that spring wheat will likely benefit from the continued increase in atmospheric CO2 concentration.