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United States Department of Agriculture

Agricultural Research Service

Research Project: DEVELOPMENT OF SOYBEAN GENEOTYPES AND MANAGEMENT SYSTEMS FOR EARLY SEASON AND STRESS ENVIRONMENTS

Location: Crop Genetics Research Unit

Title: Effect of shade on seed protein oil fatty acids and minerals in soybean lines varying in seed germinability in the Early Soybean Production System

Authors
item BELLALOUI, NACER
item SMITH, JAMES
item GILLEN, ANNE
item FISHER, DANIEL
item MENGISTU, ALEMU

Submitted to: American Journal of Plant Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 21, 2011
Publication Date: January 15, 2012
Citation: Bellaloui, N., Smith, J.R., Gillen, A.M., Fisher, D.K., Mengistu, A. 2012. Effect of shade on seed protein oil fatty acids and minerals in soybean lines varying in seed germinability in the Early Soybean Production System. American Journal of Plant Sciences. 3:84-95.

Interpretive Summary: The cause of poor seed quality (germination) of soybean produced in the Early Soybean Production System in the midsouth U.S.A. is still not completely understood. Temperature, solar radiation, and soybean variety may all be important factors involved. Therefore, the objective of this research was to evaluate seed quality components (protein, oil, minerals, and germination) in low and high germination soybean genotypes (varieties) in a full-sunlight environment (unshaded) and in a low radiation environment (shaded) that reduced light intensity by about 50% and temperature by about 10 oF. Results showed that shade resulted in higher total oil, linoleic and linolenic fatty acids, and lower protein and oleic fatty acid. Shade also resulted in higher seed boron, iron, and nitrogen concentrations. Seed boron percentage was positively correlated with germination and protein. Our research demonstrated that light intensity combined with temperature can alter seed quality components. Genotypes with higher germination had lower percentages of hardseededness (hardseededness refers to the resistance of seed coat to water entry). Higher germination and lower hardseededness are desirable traits for soybean seed. This research increases knowledge of the causes of poor seed quality and aids in the development of soybean genotypes with high seed germination and better seed composition.

Technical Abstract: The cause of poor seed quality (germination) of soybean produced in the Early Soybean Production System in the midsouth U.S.A. is still not completely understood. Temperature, solar radiation, and soybean genotype may all be important factors involved. The objective of this research was to evaluate seed composition, mineral level, and nitrogen assimilation in high and low germinability soybean plant introductions in a full-sunlight environment (unshaded) and a low-light intensity environment (shaded). Shade netting was employed in field plots that reduced light intensity by about 50% and air temperature by about 10 ºF/6 ºC. A two-year field experiment was conducted on soybean accessions with high germinability (PI 587982A and PI 603723), low germinability (PI 80480 and PI 84976-1), and on soybean cultivars (DSR-3100 RR STS and Pella 86). Results showed that shade resulted in higher total oil, linoleic, and linolenic acids, and lower protein and oleic acid. Shade also resulted in lower nitrogen assimilation, leaf chlorophyll concentration, but higher seed total boron, iron, and nitrogen concentrations. Seed structural boron percentage was positively correlated with germination and protein. Structural boron percentage was higher under shade than under unshade in lines with higher germinability (PI 587982A and PI 603723). Our research demonstrated that light intensity combined with temperature can alter seed constituents. Higher germinability lines had higher germination rates and lower percentages of hardseededness, desirable traits for soybean seed.

Last Modified: 9/10/2014