ARS | Publication request: Characterization, Genetic Variation, and Combining Ability of Maize Traits Beneficial to the Production of Cellulosic Ethanol

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 28, 2008
Publication Date: January 5, 2009
Citation: Lorenz, A.J., Coors, J.G., De Leon, N., Wolfrum, E.J., Hames, B.R., Sluiter, A.D., Weimer, P.J. 2009. Characterization, Genetic Variation, and Combining Ability of Maize Traits Beneficial to the Production of Cellulosic Ethanol. Crop Science. 49:85-98.

Interpretive Summary: Corn stover, the residue remaining after removal of the ear of corn, is a potential raw material from which to make cellulosic ethanol. Corn hybrids used for silage (when whole plant is harvested and fermented) have higher stover yields than do hybrids used for grain production. However, it is not known whether there is enough genetic variation in silage hybrids to support breeding efforts to improve stover yield and the amount of ethanol that can be produced from the stover (bioconversion potential). We examined a large number of corn hybrids grown at different locations for characteristics important for breeding improvement. Differences in yield were substantial, while differences in bioconversion potential were considerably smaller. Our results suggest that utilizing existing genetic variation of corn hybrids could substantially increase the amount of biofuels produced from a unit area of land based on increased yield, but not on bioconversion potential. The results of this study will guide breeders in further improvements in corn stover as a raw material for cellulosic ethanol.

Technical Abstract: Maize stover has been identified as an important feedstock for the production of cellulosic ethanol. Our objectives were to measure hybrid effect and combining ability patterns of traits related to cellulosic ethanol production, determine if germplasm and mutations used for silage production would also be beneficial for feedstock production, and examine relationships between traits that are relevant to selective breeding. We evaluated grain hybrids, germplasm bred for silage production, brown-midrib hybrids, and a leafy hybrid. Yield and composition traits were measured in four environments. There was a 53% difference in stover yield between commercial grain hybrids that were equivalent for other production-related traits. Silage germplasm may be useful for increasing stover yield and reducing lignin concentration. We found more variability for stover yield than theoretical ethanol potential (TEP; L Mg-1). Few unfavorable correlations were found among compositional and agronomic characteristics that would limit selection gain. Our results suggest that utilizing standing genetic variation of maize could substantially increase the amount of biofuels produced from a unit area of land.