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Analysis of soybean seed proteins: Quantitative variation and environmental interactions among high-protein plant introductions and elite breeding lines
Abstract
The ratio of the glycinin to β-conglycinin seed proteins in soybean has been used to judge nutritional quality. Efforts to improve the quality of soybean seed proteins could focus on increasing the glycinin to β-conglycinin ratio. The first objective of this study was to characterize quantitative variation for the glycinin to β-conglycinin ratio among 80 high-protein plant introductions and 80 high-yielding elite breeding lines. The second objective was to characterize genotype-by-environment interaction effects on the glycinin to β-conglycinin ratio for the 160 genotypes. Eighty MG I–II genotypes and 80 MG III–IV genotypes were evaluated. Field trials were conducted in four environments and agronomic data collected. The glycinin to β-conglycinin ratio (GBRAT) was calculated from protein bands quantified with an electrophoresis/gel scanning method. Significant differences among genotypes were found for all traits in each environment and across environments in each maturity group set of genotypes. High protein (HP) and high yield (HY) genotype class means were significantly different for GBRAT, total protein and oil content, yield and 100-seed weight and maturity. The high yield genotypes had higher mean values for GBRAT in both maturity groups. Genotype-by-environment interaction effects were significant for the HP and HY genotype classes in the MG II genotypes for GBRAT, protein content, yield and maturity and significant for all traits in the MG III genotypes. Genotype-environment interaction effects on GBRAT were generally changes in magnitude, not rank, indicating that breeding and selection for the GBRAT trait would be effective across environments. Genotypic variation for GBRAT among high-yield lines was equal to or greater than σ2G among high protein lines. This finding indicates that breeding and selection among elite, adapted high-yield germplasm could modify protein subunit composition. When breeding objectives include improvement of seed protein quality, GBRAT, measured by the electrophoresis/gel scanning method, could be a useful selection tool.
Subject Area
Agronomy|Genetics|Botany
Recommended Citation
Comfort, Gaylene Marie, "Analysis of soybean seed proteins: Quantitative variation and environmental interactions among high-protein plant introductions and elite breeding lines" (1998). ETD collection for University of Nebraska-Lincoln. AAI9917825.
https://digitalcommons.unl.edu/dissertations/AAI9917825