Radiation capture and conversion efficiencies of Miscanthus sacchariflorus , M. sinensis and their naturally occurring hybrid M . ×  giganteus

Journal Article · Fri Feb 26 00:00:00 EST 2016 · Global Change Biology. Bioenergy

DOI:https://doi.org/10.1111/gcbb.12331· OSTI ID:1239700

Davey, Christopher Lyndon ^[1]; Jones, Laurence Edmund ^[1]; Squance, Michael ^[1]; Purdy, Sarah Jane ^[1]; Maddison, Anne Louise ^[1]; Cunniff, Jennifer ^[2]; Donnison, Iain ^[1]; Clifton‐Brown, John ^[1]

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1. Institute of Biological, Environmental and Rural Sciences (IBERS) Aberystwyth University Gogerddan Aberystwyth, Ceredigion SY23 3EE UK
2. Rothamsted Research Harpenden, Hertfordshire AL5 2JQ UK

Abstract Miscanthus is a rhizomatous C4 grass of great interest as a biofuel crop because it has the potential to produce high yields over a wide geographical area with low agricultural inputs on marginal land less suitable for food production. At the moment, a clonal interspecific hybrid Miscanthus  ×  giganteus is the most widely cultivated and studied in Europe and the United States, but breeding programmes are developing newer more productive varieties. Here, we quantified the physiological processes relating to whole season yield in a replicated plot trial in Wales, UK . Light capture and conversion efficiency were parameterized for four carefully selected genotypes ( M. sinensis , M. sacchariflorus and Miscanthus  ×  giganteus ). Differences in the canopy architecture in mature stands as measured by the extinction coefficient ( k ) were small (0.55–0.65). Sensitivity analysis on a mathematical model of Miscanthus was performed to quantify the accumulative intercepted photosynthetically active radiation ( iPAR ) in the growing season using (i) k, (ii) variation in the thermal responses of leaf expansion rate, (iii) base temperature for degree days and (iv) date start of canopy expansion. A 10% increase in k or leaf area per degree day both had a minimal effect on iPAR (3%). Decreasing base temperature from 10 to 9 °C gave an 8% increase in iPAR . If the starting date for canopy expansion was the same as shoot emergence date, then the iPAR increases by 12.5%. In M . ×  giganteus, the whole season above ground and total (including below ground) radiation‐use efficiency ( RUE ) ranged from 45% to 37% higher than the noninterspecific hybrid genotypes. The greater yields in the interspecific hybrid M. × giganteus are explained by the higher RUE and not by differences in iPAR or partitioning effects. Studying the mechanisms underlying this complex trait could have wide benefits for both fuel and food production.

• Sponsoring Organization: USDOE
• OSTI ID: 1239700
• Alternate ID(s): OSTI ID: 1239701
• Journal Information: Global Change Biology. Bioenergy, Journal Name: Global Change Biology. Bioenergy Vol. 9 Journal Issue: 2; ISSN 1757-1693
• Publisher: Wiley-Blackwell
• Country of Publication: United Kingdom
• Language: English