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Title: Thermal Properties of Starch From New Corn Lines as Impacted by Environment and During Line Development

Thesis/Dissertation ·
DOI:https://doi.org/10.2172/822054· OSTI ID:822054
 [1]
  1. Iowa State Univ., Ames, IA (United States)

The objectives of this research were to further characterize exotic by adapted corn inbreds by studying the impact of environment on their starch thermal properties, and investigating the development of starch thermal properties during kernel maturation by using differential scanning calorimetry (DSC). A method to expedite identification of unusual starch thermal traits was investigated by examining five corn kernels at a time, instead of one kernel, which the previous screening methods used. Corn lines with known thermal functions were blended with background starch (control) in ratios of unique starch to control starch, and analyzed by using DSC. Control starch was representative of typical corn starch. The values for each ratio within a mutant type were unique (α < 0.01) for most DSC measurements. These results supported the five-kernel method for rapidly screening large amounts of corn germplasm to identify unusual starch traits. The effects of 5 growing locations on starch thermal properties from exotic by adapted corn and Corn Belt lines were studied using DSC. The warmest location, Missouri, generally produced starch with greater gelatinization onset temperature (ToG), narrower range of gelatinization (RG), and greater enthalpy of gelatinization (ΔHG). The coolest location, Illinois, generally resulted in starch with lower ToG, wider RG, and lower ΔHG. Starch from the Ames 1 farm had thermal properties similar to those of Illinois, whereas starch from the Ames 2 farm had thermal properties similar to those of Missouri. The temperature at Ames 2 may have been warmer since it was located near a river; however, soil type and quality also were different. Final corn starch structure and function change during development and maturity. Thus, the changes in starch thermal properties during 5 stages of endosperm development from exotic by adapted corn and Corn Belt lines at two locations were studied by using DSC. The ToG tended to decrease during maturation of the kernel, whereas theΔHG tended not to change. Retrogradation parameters did not vary greatly among days after pollination (DAP) and between locations. Genotypes were affected differently by environments and significant interactions were found between genotype, environment,and DAP.

Research Organization:
Ames Lab., Ames, IA (United States)
Sponsoring Organization:
USDOE Office of Science (SC)
DOE Contract Number:
W-7405-Eng-82
OSTI ID:
822054
Report Number(s):
IS-T 2547; TRN: US200412%%382
Resource Relation:
Other Information: TH: Thesis (M.S.); Submitted to Iowa State Univ., Ames, IA (US); PBD: 12 Dec 2003
Country of Publication:
United States
Language:
English