ARS | Publication request: QUALITY CHARACTERISTICS OF GRASSES AND GENETIC IMPROVEMENT FOR BIOMASS

Submitted to: Biotechnology for Fuels and Chemicals Symposium Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: May 7, 2000
Publication Date: N/A

Technical Abstract: Perennial grasses, in particular switchgrass, have been advocated for use as biomass energy crops because of their potential for high biomass yield under relatively low fertilizer and pesticide inputs. With combustion energy conversion technologies, yield of biomass is the major consideration for genetic improvement of a biomass crop; however, for use in liquid fuel systems feedstock quality characteristics also become of major importance in order to maximize yield of fermentable sugars for ethanol production. Increasing the proportion of polysaccharides in the cell wall, particularly cellulose, and decreasing lignin content of grasses will provide more sugars for fermentation to ethanol. The genetic variation for biomass quality traits is high in grasses. Progress has been achieved in switchgrass to modify quality traits through conventional breeding. A transformation system has been developed for switchgrass that will allow insertion of transgenes to stimulate polysaccharide biosynthesis and repress lignin accumulation. The pool of candidate genes for modifying lignification is large, but relatively few genes have been cloned for polysaccharide synthesis. Experience with transgenic tobacco and conventionally bred switchgrass indicates that plant fitness can be negatively impacted when biomass traits are improved. Selection for agronomic fitness must continue as biomass quality traits are enhanced.