skip to main content

DOE PAGESDOE PAGES

Title: Stover composition in maize and sorghum reveals remarkable genetic variation and plasticity for carbohydrate accumulation

Carbohydrates stored in vegetative organs, particularly stems, of grasses are a very important source of energy. We examined carbohydrate accumulation in adult sorghum and maize hybrids with distinct phenology and different end uses (grain, silage, sucrose or sweetness in stalk juice, and biomass). Remarkable variation was observed for nonstructural carbohydrates and structural polysaccharides during three key developmental stages both between and within hybrids developed for distinct end use in both species. At the onset of the reproductive phase (average 65 days after planting, DAP), a wide range for accumulation of non-structural carbohydrates (free glucose and sucrose combined), was observed in internodes of maize (11-24%) and sorghum (7-36%) indicating substantial variation for transient storage of excess photosynthate during periods of low grain or vegetative sink strength. Remobilization of these reserves for supporting grain fill or vegetative growth was evident from lower amounts in maize (8-19%) and sorghum (9-27%) near the end of the reproductive period (average 95 DAP). At physiological maturity of grain hybrids (average 120 DAP), amounts of these carbohydrates were generally unchanged in maize (9-21%) and sorghum (16-27%) suggesting a loss of photosynthetic assimilation due to weakening sink demand. Nonetheless, high amounts of non-structural carbohydrates at maturity even inmore » grain maize and sorghum (15-18%) highlight the potential for developing dual-purpose (grain/stover) crops. For both species, the amounts of structural polysaccharides in the cell wall, measured as monomeric components (glucose and pentose), decreased during grain fill but remained unchanged thereafter with maize biomass possessing slightly higher amounts than sorghum. In conclusion, availability of carbohydrates in maize and sorghum highlights the potential for developing energy-rich dedicated biofuel or dual-purpose (grain/stover) crops.« less
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [2] ;  [2]
  1. Clemson Univ., Clemson, SC (United States). Dept. of Genetics and Biochemistry
  2. Univ. of Wisconsin, Madison, WI (United States). Dept. of Agronomy, DOE Great Lakes Bioenergy Research Center
  3. Federal Univ. of Goias, Goiania (Brazil). Institute of Mathematics and Statistics
  4. Univ. of Michigan, Ann Arbor, MI (United States). Center for Chemical Genomics
  5. Texas A&M Univ., College Station, TX (United States). Dept. of Soil and Crop Sciences
Publication Date:
OSTI Identifier:
1280815
Grant/Contract Number:
FC02-07ER64494
Type:
Accepted Manuscript
Journal Name:
Frontiers in Plant Science
Additional Journal Information:
Journal Volume: 7; Journal ID: ISSN 1664-462X
Publisher:
Frontiers Research Foundation
Research Org:
Univ. of Wisconsin, Madison, WI (United States). DOE Great Lakes Bioenergy Research Center
Sponsoring Org:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23); DOE Great Lakes Bioenergy Research Center (GLBRC); Clemson University
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES sorghum; maize; biofuels; biofeedstocks; non-structural carbohydrates; structural carbohydrates; abiotic stress responses; crop-livestock systems; cell-wall; alkaline-degradation; biofuel production; ethanol-production; leaf senescence; ear removal; yield; sugar