2013 Annual Report
Objective 2: Improve establishment, harvest management, and storage methods to reduce nitrogen inputs, increase the profitability of crop rotations, increase the recovery of dry matter and nonstructural carbohydrates, improve the energy density of baled hays, and mitigate the negative effects of rainfall on ensiling, storage, and feeding characteristics of rain-damaged silages. Sub-objective 2A. Identify optimal plant spacing to maximize yield of biomass alfalfa. Sub-objective 2B. Develop improved methods for interseeding alfalfa into maize to bring alfalfa into full production the following year. Sub-objective 2C. For large hay packages, quantify the effects of several baling factors on subsequent preservation performance of stored hay.
Objective 3: Improve pasture grass and legume production systems through increases in establishment capacity, persistence, productivity, resilience to climate extremes, and quality. Sub-objective 3A. Measure comparative effectiveness of mass selection, maternal half-sib selection, and marker-assisted paternal half-sib selection for persistence and biomass yield in diploid red clover. Sub-objective 3B. Determine optimal plant-selection age after establishment to simultaneously maximize genetic gain for persistence and biomass yield of red clover.
Objective 4: Improve profitability, conversion efficiency, and adaptability to climatic variation in forage and bioenergy crops. Sub-objective 4A. Quantify the effect of decreased lignin and decreased etherified ferulates on agricultural fitness of three temperate pasture species, including their tolerances to drought, heat, and grazing. Sub-objective 4B. Use a biomimetic model based on the artificial lignification of plant cell walls to identify new lignin bioengineering targets for improving the fermentability of forage and biomass crops. Sub-objective 4C. Create and evaluate a series of upland x lowland switchgrass hybrids of differing origins to determine if heterosis is related to geographic origin of either parent.
Objective 2. High vs. low-density plant spacing will be evaluated to determine the effect on biomass yield for high-biomass alfalfa cultivars. Gibberellin-based growth regulator treatments will be evaluated for their effect on establishment and seeding-year biomass yield for alfalfa interseeded into maize. Propionic acid preservatives will be evaluated to determine their effect on reducing spontaneous heating and nutrient loss of large-rectangular bales of alfalfa hay.
Objective 3. The comparative effectiveness of mass selection, half-sib selection, and marker-assisted half-sib selection will be determined in an empirical study designed to improve persistence and forage yield of red clover. The optimal age for selection of red clover plants will be identified by evaluating empirical gains from selection for persistence and forage yield on selection nurseries of various ages and degrees of plant mortality.
Objective 4. The effect of lignin and etherified ferulates on persistence and forage yield will be evaluated in a series of field experiments designed to evaluate progeny with high or low levels of each cell-wall component in three grass species. The direct effects of monolignol substitutes on cell-wall fermentability and saccharification will be evaluated by using these novel compounds, compared to classical monolignols, as substrates for artificial lignification of maize primary cell walls. Heterosis between upland and lowland switchgrass ecotypes will be evaluated in a series of experiments to quantify hybrid vigor and to identify sources of variation that contribute to variation in hybrid vigor.
Dien, B.S., Casler, M.D., Hector, R.E., Iten, L.B., Nichols, N.N., Mertens, J.A., Cotta, M.A. 2012. Biochemical processing of reed canarygrass into fuel ethanol. International Journal of Low-Carbon Technologies. 7:338-347.
Coblentz, W.K., Coffey, K.P., Young, A.N., Bertram, M.G. 2013. Storage characteristics, nutritive value, energy content, and in-vivo digestibility of moist large-rectangular bales of alfalfa-orchardgrass hay treated with a propionic-acid-based preservative. Journal of Dairy Science. 96:2521-2535.
Parrish, D. J., Casler, M. D., Monti, A. 2012. The evolution of switchgrass as an energy crop. In: Monti, A., editor. Switchgrass. London, UK: Springer. pp. 1-28.
Riday, H., Johnson, D.W., Heyduk, K., Raasch, J.A., Darling, M.M., Sandman, J.E. 2013. Paternity testing in an autotetraploid alfalfa breeding polycross. Euphytica. Euphytica 194:335-349.
Brink, G.E., Jackson, R.D., Alber, N.B. 2013. Residual sward height effects on growth and nutritive value of grazed temperate perennial grasses. Crop Science. DOI: 10.2135/cropsci2013.01.0068.
Casler, M.D., Smart, A. 2013. Plant mortality and natural selection may increase biomass yield in switchgrass swards. Crop Science. 53(2):500-506.
Vogel, K.P., Mitchell, R., Sarath, G., Jung, H.G., Dien, B.S., Casler, M.D. 2013. Switchgrass biomass composition altered by six generations of divergent breeding for digestibility. Crop Science. 53:853-862. DOI 10.2135/cropsci2012.09.0542
Lu, F., Lipka, A.E., Glaubitz, J.C., Elshire, R., Cherney, J.H., Casler, M.D., Buckler IV, E.S., Costich, D. 2013. Switchgrass genomic diversity, ploidy and evolution: novel insights from a network-based SNP discovery protocol. PLoS Genetics. 9(1):e1003215. DOI:10.1371/journal.pgen.1003215.
Watrud, L., Reichman, J., Bollman, M., Smith, B., Lee, E., Jastrow, J., Casler, M.D., Collins, H.P., Fransen, S., Mitchell, R., Owens, V.N., Bean, B., Rooney, W.L., Tyler, D.D., King, G.A. 2012. Chemistry and microbial functional diversity differences in biofuel crop and grassland soils in multiple geographies. BioEnergy Research. 6(2):601-619.
Casler, M.D. 2012. Switchgrass breeding, genetics, and genomics. In: Monti, A., editor. Switchgrass. London, UK: Springer. p. 29-54.