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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Does greater leaf-level photosynthesis explain the larger solar energy conversion efficiency of Miscanthus relative to switchgrass?
AU - Dohleman, F. G.
AU - Heaton, E. A.
AU - Leakey, A. D. B.
AU - Long, S. P.
PY - 2009/11
Y1 - 2009/11
N2 - C(4) perennial grasses are being considered for bioenergy because of their high productivity and low inputs. In side-by-side replicated trials, Miscanthus (Miscanthus x giganteus) has previously been found more than twice as productive as switchgrass (Panicum virgatum). The hypothesis that this difference is attributable to higher leaf photosynthetic rates was tested on established plots of switchgrass and Miscanthus in central Illinois with > 3300 individual measurements on 20 dates across the 2005 and 2006 growing seasons. Seasonally integrated leaf-level photosynthesis was 33% higher in Miscanthus than switchgrass (P <0.0001). This increase in carbon assimilation comes at the expense of additional transpiration since stomatal conductance was on average 25% higher in Miscanthus (P <0.0001). Whole-chain electron transport rate, measured simultaneously by modulated chlorophyll fluorescence, was similarly 23% higher in Miscanthus (P <0.0001). Efficiencies of light energy transduction into whole chain photosynthetic electron transport, leaf nitrogen use and leaf water use were all significantly higher in Miscanthus. These may all contribute to its higher photosynthetic rates, and in turn, productivity. Systematic measurement of photosynthesis over two complete growing seasons in the field provides a unique dataset explaining why the productivity of these two species differs and for validating mechanistic production models for these emerging bioenergy crops.
AB - C(4) perennial grasses are being considered for bioenergy because of their high productivity and low inputs. In side-by-side replicated trials, Miscanthus (Miscanthus x giganteus) has previously been found more than twice as productive as switchgrass (Panicum virgatum). The hypothesis that this difference is attributable to higher leaf photosynthetic rates was tested on established plots of switchgrass and Miscanthus in central Illinois with > 3300 individual measurements on 20 dates across the 2005 and 2006 growing seasons. Seasonally integrated leaf-level photosynthesis was 33% higher in Miscanthus than switchgrass (P <0.0001). This increase in carbon assimilation comes at the expense of additional transpiration since stomatal conductance was on average 25% higher in Miscanthus (P <0.0001). Whole-chain electron transport rate, measured simultaneously by modulated chlorophyll fluorescence, was similarly 23% higher in Miscanthus (P <0.0001). Efficiencies of light energy transduction into whole chain photosynthetic electron transport, leaf nitrogen use and leaf water use were all significantly higher in Miscanthus. These may all contribute to its higher photosynthetic rates, and in turn, productivity. Systematic measurement of photosynthesis over two complete growing seasons in the field provides a unique dataset explaining why the productivity of these two species differs and for validating mechanistic production models for these emerging bioenergy crops.
KW - Miscanthus
KW - Panicum
KW - bioenergy
KW - biofuel
KW - diurnal
KW - feedstock
KW - fluorescence
KW - photosynthesis
KW - productivity
KW - switchgrass
KW - NITROGEN-USE EFFICIENCY
KW - X GIGANTEUS
KW - C-4 PHOTOSYNTHESIS
KW - ZEA-MAYS
KW - GROWTH TEMPERATURES
KW - NAD-ME
KW - GRASSES
KW - CROP
KW - PHOTOINHIBITION
KW - TOLERANCE
U2 - 10.1111/j.1365-3040.2009.02017.x
DO - 10.1111/j.1365-3040.2009.02017.x
M3 - Journal article
VL - 32
SP - 1525
EP - 1537
JO - Plant, Cell and Environment
JF - Plant, Cell and Environment
SN - 0140-7791
IS - 11
ER -