Abstract
Public appetite for fossil fuels continues to drive energy prices and foment the build-up of intractable environmental problems. Ethanol (ETOH) production from lignocellulosic biomass grown in marginal lands offers a sustainable alternative without diverting arable land from food and feed production. The quantity and quality of lignocellulosic biomass can be enhanced by the abundant genetic diversity for biomass production as well as stem sugar and lignin composition in sorghum (Sorghum bicolor L. Moench). The objective of this study was to assess yield and quality of lignocellulosic biomass enhancement for ethanol production potential in a population of sorghum derived from two cultivars with contrasting biomass yield and compositional traits. We tested 236 recombinant inbred lines (RIL) of sorghum in a randomized complete block design (RCBD) with two replications for lignocellulosic biomass performance and determined hemicellulose, cellulose and lignin concentrations through detergent fiber analysis (DFA). The stover compositional values were used to estimate theoretical ethanol yield (ETOH on a mass basis) and production (ETOH on an area basis). Results showed that RIL carrying the brown midrib mutation had significantly higher theoretical glucose recovery (released glucose from cellulose, > 200 g kg-1). Those carrying both mutations, had high theoretical ethanol yield (>400 L ton-1) and high theoretical ethanol production (>14,500 L ha-1). Lignin concentration was determined as most reliable predictor (R2 = 0.67) for glucose recovery. Lignin and stem sugar concentrations (R2 = 0.46 and 0.35, respectively) were good predictors for ethanol yield. Stover yield traits (R2 = 0.89) were most important determinants for ethanol production. Our findings suggest that careful breeding of sorghum for genetic enhancement of biomass quantity and quality could double lignocellulosic ethanol yields.
Highlights
Fossil fuel dependency and increased greenhouse gases are major concerns that have caught the attention of environmentalists, economists, as well as scientists
The Year × recombinant inbred lines (RIL) interaction was only significant for fresh stover yield (FSY) (Table 2)
The significant variation observed in biomass traits for the Year effect and the Year × RIL interaction effect could be explained by difference on precipitation rates and temperatures between years
Summary
Fossil fuel dependency and increased greenhouse gases are major concerns that have caught the attention of environmentalists, economists, as well as scientists. Rapid expansion of the global economy sustains an insatiable hunger for energy, leading to a strong dependency on fossil fuel products. This dependency creates a growing consumer demand that raises petroleum product prices affecting the economy within and among countries (Davis et al, 2008). A large volume of lignocellulosic biomass is produced from a number of crops every year. Field crops produce considerable amounts of both grain and stover. Grain from crops is harvested and used for human (food) and animal (feed) consumption, while stover (lignocellulosic biomass) is often left unharvested on-farm every crop season (Nelson et al, 2011). Though some may consider the stover left on-farm a waste, agronomists recognize the value of crop residues for reducing soil erosion and building soil organic matter (Gupta and Verma, 2015)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
