Stability of Cell Wall Composition and Saccharification Efficiency in Miscanthus across Diverse Environments

Abstract

To investigate the potential effects of differences between growth locations on the cell wall composition and saccharification efficiency of the bioenergy crop miscanthus, a diverse set of 15 accessions were evaluated in six locations across Europe for the first 3 years following establishment. High-throughput quantification of cellulose, hemicellulose and lignin contents, as well as cellulose and hemicellulose conversion rates was achieved by combining near-infrared reflectance spectroscopy (NIRS) and biochemical analysis. Prediction models were developed and found to predict biomass quality characteristics with high accuracy. Location significantly affected biomass quality characteristics in all three cultivation years, but location-based differences decreased toward the third year as the plants reached maturity and the effect of location-dependent differences in the rate of establishment reduced. In all locations extensive variation in accession performance was observed for quality traits. The performance of the different accessions in the second and third cultivation year was strongly correlated, while accession performance in the first cultivation year did not correlate well with performance in later years. Significant genotype-by-environment (G × E) interactions were observed for most traits, revealing differences between accessions in environmental sensitivity. Stability analysis of accession performance for calculated ethanol yields suggested that selection for good and stable performance is a viable approach. Environmental influence on biomass quality is substantial and should be taken into account in order to match genotype, location and end-use of miscanthus as a lignocellulose feedstock.

Keywords: GGE biplot; biomass quality; ethanol; genotype-by-environment interaction; miscanthus; multi-location trial; near-infrared spectroscopy (NIRS); stability.

Figure 1

Variation in accession means of 15 miscanthus accessions for cell wall composition characteristics in six growth locations and three cultivation years (1 = 2012–2013, 2 = 2013–2014, and 3 = 2014–2015).

Figure 2

Variation in accession means of 15 miscanthus accessions for conversion efficiency characteristics in six growth locations and three cultivation years (1 = 2012–2013, 2 = 2013–2014, and 3 = 2014–2015).

Figure 3

Scatter plot matrix of calculated ethanol yields (g/kg dm) of the first [1] and the second [2] cultivation year of 15 miscanthus accessions in six locations compared to that of the third cultivation year [3].

Figure 4

GGL biplot of variation in accession performance in calculated ethanol yield (g/kg dm) across six locations in the third cultivation year (2014–2015). Numbers represent accession OPM codes.