title: Variation in the chemical composition of wheat straw: the role of tissue ratio and composition.
abstract: BACKGROUND
  Wheat straw is an attractive substrate for second generation ethanol production because it will complement and augment wheat production rather than competing with food production. However, like other sources of lignocellulosic biomass, even from a single species, it is heterogeneous in nature due to the different tissues and cell types, and this has implications for saccharification efficiency. The aim of this study has been to use Fourier transform infrared (FTIR) spectroscopy and Partial least squares (PLS) modelling to rapidly screen wheat cultivars for the levels of component tissues, the carbohydrate composition and lignin content, and the levels of simple cross-linking phenolics such as ferulic and diferulic acids.
  
  
  RESULTS
  FTIR spectroscopy and PLS modelling was used to analyze the tissue and chemical composition of wheat straw biomass. Predictive models were developed to evaluate the variability in the concentrations of the cell wall sugars, cell wall phenolics and acid-insoluble lignin. Models for the main sugars, phenolics and lignin were validated and then used to evaluate the variation in total biomass composition across 90 cultivars of wheat grown over two seasons.
  
  
  CONCLUSIONS
  Whilst carbohydrate and lignin components varied across the varieties, this mainly reflected differences in the ratios of the component tissues rather than differences in the composition of those tissues. Further analysis indicated that on a mol% basis, relative levels of sugars within the tissues varied to only a small degree. There were no clear associations between simple phenolics and tissues. The results provide a basis for improving biomass quality for biofuels production through selection of cultivars with appropriate tissue ratios.
authors.affiliation: Institute of Food Research, Norwich Research Park, Colney, Norwich, NR4 7UA UK.
authors.forename: Samuel Ra
authors.initials: SR
authors.lastname: Collins
authors.affiliation: Institute of Food Research, Norwich Research Park, Colney, Norwich, NR4 7UA UK.
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Wellner
authors.affiliation: Institute of Food Research, Norwich Research Park, Colney, Norwich, NR4 7UA UK.
authors.forename: Isabel
authors.initials: I
authors.lastname: Martinez Bordonado
authors.affiliation: John Innes Centre, Norwich Research Park, Colney, Norwich, NR4 7UH UK ; Present address: Department of Biology, University of York, Wentworth Way, Heslington, York, YO10 5DD UK.
authors.forename: Andrea L
authors.initials: AL
authors.lastname: Harper
authors.affiliation: John Innes Centre, Norwich Research Park, Colney, Norwich, NR4 7UH UK.
authors.forename: Charlotte N
authors.initials: CN
authors.lastname: Miller
authors.affiliation: John Innes Centre, Norwich Research Park, Colney, Norwich, NR4 7UH UK ; Present address: Department of Biology, University of York, Wentworth Way, Heslington, York, YO10 5DD UK.
authors.forename: Ian
authors.initials: I
authors.lastname: Bancroft
authors.affiliation: Institute of Food Research, Norwich Research Park, Colney, Norwich, NR4 7UA UK.
authors.forename: Keith W
authors.initials: KW
authors.lastname: Waldron
keywords: Biomass; Composition; Ethanol yields; Lignocellulose; Wheat straw