Jennifer Cunniff

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

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.

Development of a sink–source interaction model for the growth of short-rotation coppice willow and in silico exploration of genotype×environment effects

Highlight The process-based model LUCASS gave insights into the sink–source control of willow growth, identifying key parameters and predicting the performance of contrasting canopy phenotypes in different environments.

Lighting the way to willow biomass production

Biofuels produced from willow could help reduce our dependence on fossil fuels. To maximise yields per hectare light interception and utilisation of the plant canopy need to be optimised. Jennifer Cunniff and Marianna Cerasuolo explain how this target can be reached by integrating morphological field measurements and modelling techniques.

Non-structural carbohydrate profiles and ratios between soluble sugars and starch serve as indicators of productivity for a bioenergy grass

Miscanthus is a perennial bioenergy crop that offers a sustainable alternative to fossil fuels. We sought to identify candidate metabolic biomarkers of productivity that may be used as a method of screening for superior individuals in breeding programmes. Our experiments were carried out over two years and two sites in four genotypes. The concentration of fructose positively correlated whereas starch and the ratio of soluble sugars to starch negatively correlated with three biomass traits: yield, stem height and growth rate. Our results show the potential of the carbohydrate metabolic profile as a biomarker of productivity in a perennial energy crop.