|Barbour, Nancy - UNIVERSITY OF MINNESOTA|
|Orf, J - UNIVERSITY OF MINNESOTA|
Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: November 8, 1996
Publication Date: N/A
Technical Abstract: Thermal energy intensity (TEI) during seed filling can have a large impact on the final protein and oil content of soybean seeds. This study was undertaken to determine whether the response of seed composition to TEI reflected a change in the rate and/or duration of protein and oil accumulation. Nine genotypes varying in seed protein content from 32% to 48% (at 13% moisture) were grown at 27/20 deg C under controlled conditions until flowering was complete. Air temperature then was maintained at either 20/12 deg C, 27/20 deg C, or 35/27 deg C during seed filling and maturation. Plants were harvested twice during rapid seed fill and at physiological maturity to estimate rates and durations of dry matter, protein, and oil accumulation in the seeds. The response of final seed weight and composition (% protein and % oil) to increasing TEI during seed filling varied with genotype. A low-protein line Evans, for example, produced smaller seeds with greater % protein as TEI increased, while a high-protein line NC111 produced similarly-sized seeds with greater % oil as TEI increased. The extent to which the rate and duration of protein and oil accumulation were affected by TEI also was genotype dependent.