OPEN ACCESS ARTICLE

This Article Free via Open Access: OA OA Full Text Full Text (PDF) Supplemental Data OA All Versions of this Article: 150/4/2104    most recent pp.109.139162v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Related articles in Plant Physiol. Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Web of Science (3) Citing Articles via Google Scholar Google Scholar Articles by Dohleman, F. G. Articles by Long, S. P. Search for Related Content PubMed PubMed Citation Articles by Dohleman, F. G. Articles by Long, S. P. Agricola Articles by Dohleman, F. G. Articles by Long, S. P. Related Collections The Grasses

WHOLE PLANT AND ECOPHYSIOLOGY

More Productive Than Maize in the Midwest: How Does Miscanthus Do It?^1,[W],[OA]

Department of Plant Biology (F.G.D., S.P.L.), Department of Crop Sciences (S.P.L.), and Institute for Genomic Biology (S.P.L.), University of Illinois, Urbana, Illinois 61801

In the first side-by-side large-scale trials of these two C₄ crops in the U.S. Corn Belt, Miscanthus (Miscanthus x giganteus) was 59% more productive than grain maize (Zea mays). Total productivity is the product of the total solar radiation incident per unit land area and the efficiencies of light interception (_i) and its conversion into aboveground biomass (_ca). Averaged over two growing seasons, _ca did not differ, but _i was 61% higher for Miscanthus, which developed a leaf canopy earlier and maintained it later. The diurnal course of photosynthesis was measured on sunlit and shaded leaves of each species on 26 dates. The daily integral of leaf-level photosynthetic CO₂ uptake differed slightly when integrated across two growing seasons but was up to 60% higher in maize in mid-summer. The average leaf area of Miscanthus was double that of maize, with the result that calculated canopy photosynthesis was 44% higher in Miscanthus, corresponding closely to the biomass differences. To determine the basis of differences in mid-season leaf photosynthesis, light and CO₂ responses were analyzed to determine in vivo biochemical limitations. Maize had a higher maximum velocity of phosphoenolpyruvate carboxylation, velocity of phosphoenolpyruvate regeneration, light saturated rate of photosynthesis, and higher maximum quantum efficiency of CO₂ assimilation. These biochemical differences, however, were more than offset by the larger leaf area and its longer duration in Miscanthus. The results indicate that the full potential of C₄ photosynthetic productivity is not achieved by modern temperate maize cultivars.

The author responsible for distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (www.plantphysiol.org) is: Stephen P. Long (slong{at}illinois.edu).

^[W] The online version of this article contains Web-only data.

^[OA] Open access articles can be viewed online without a subscription.

www.plantphysiol.org/cgi/doi/10.1104/pp.109.139162

^* Corresponding author; e-mail slong{at}illinois.edu.

Received March 28, 2009; accepted June 14, 2009; published June 17, 2009.

Related articles in Plant Physiol.:

On the Inside

Peter V. Minorsky
Plant Physiol. 2009 150: 1762-1763. [Full Text]  

This article has been cited by other articles:

				T. Vogt Phenylpropanoid Biosynthesis Mol Plant, January 1, 2010; 3(1): 2 - 20. [Abstract] [Full Text] [PDF]