ARS | Publication request: Strategies for using molecular markers to simultaneously improve maize grain yield and stover quality for ethanol production

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: May 1, 2011
Publication Date: June 19, 2011
Citation: Bernardo, R., Jung, H.G., Massman, J.M., Lewis, M.F., Lorenzana, R.E. 2011. Strategies for using molecular markers to simultaneously improve maize grain yield and stover quality for ethanol production [abstract]. 22nd European Association for Research on Plant Breeding (EUCARPIA) Maize and Sorghum Conference, June 19-22, 2011, Opatija, Croatia. p. 62.

Technical Abstract: Maize stover represents the most abundant source of lignocellulosic biomass that can be converted to ethanol biofuel in the U.S. Our objective was to optimize the use of SNP markers to simultaneously breed for high grain yield (for non-energy and energy uses) and high stover quality for ethanol production. We measured three stover-quality traits in testcrosses of the intermated B73 x Mo17 population: concentration of cell wall glucose in dry stover (Glucose); cell wall glucose released from the stover by thermochemical pretreatment and enzymatic saccharification (Glucose Release); and concentration of lignin on a cell-wall basis (Lignin). Genetic variances were significant for grain yield, moisture, stalk and root lodging, plant height, and all three stover-quality traits. Heritabilities were 0.57 for Glucose, 0.63 for Glucose Release, and 0.68 for Lignin. Genetic and phenotypic correlations among traits were generally favorable but also reflected the complexity of stover cell wall composition. We found 152 QTL, mostly with small effects, for Glucose Release and cell wall components. Responses to three cycles of selection for Glucose, Glucose Release, and Lignin were higher with genomewide selection (which utilized all markers rather than only those with significant effects) than with selection based only on significant markers. To our knowledge, this work represents the first report of an empirical breeding experiment on genomewide selection in plants. Given the absence of major QTL and the complexity of the traits, we recommend genomewide selection for the improvement of stover-quality traits for cellulosic ethanol in maize.