ARS | Publication request: Soybean seed compostion and quality: interactions of enviroment genotype and management practices

Submitted to: Nova Hedwigia
Publication Type: Book / Chapter
Publication Acceptance Date: August 12, 2010
Publication Date: August 18, 2011
Citation: Bellaloui, N., Reddy, K.N., Bruns, H.A., Gillen, A.M., Mengistu, A., Zobiole, L.H., Fisher, D.K., Abbas, H.K., Zablotowicz, R.M., Kremer, R.J. 2011. Soybean seed compostion and quality: interactions of enviroment genotype and management practices. Nova Hedwigia. 1:1-42.

Interpretive Summary: Soybean seed is a major source of protein and energy human and animal nutrition. Seed quality and composition are known to be genetically controlled, but variability among genotypes for these characteristics exists. The physiological and biochemical mechanisms by which this variability occurs are still not completely understood, but are known to be significantly influenced by genotype, environment, management practices, and their interactions. Therefore, understanding the interaction of these factors and how they impact seed quality and composition is crucial for maintaining high yields and nutritional quality. Soybean protein is low in two major sulfur-containing amino acids, methionine and cysteine, which are currently supplemented in livestock feed, increasing production cost. Methionine and cysteine amino acids determine protein quality, and increased oleic acid and reduced linolenic acid determine the oil quality. Breeding for higher protein and protein quality, and higher oil and oil quality is still challenging because of the inherited inverse relationships between these constituents and their stability across environments and locations. For example, protein is negatively correlated with oil and yield, and storage protein glycinin (higher in sulfur-containing amino acids) is negatively correlated with beta-conglycinin (lower in sulfur containing amino acids). In spite of the success of breeding for increased protein and oleic acid lines and reduced linolenic acid lines, breaking through these inverse relationships is still a major challenge. This review highlighted major challenges in development of soybean seed with increased seed quality and composition. The review also examined current research techniques, including breeding, biotechnology, and crop management to overcome those challenges. Improving soybean seed quality for conventional uses such as food and feed and for specialty value-added uses such as tofu, soymilk, and other soy products was also examined. This information is beneficial for soybean breeders to develop and release cultivars to suit specific target locations to grow new value-added soybeans or select for specific seed composition qualities under environmental stress factors of drought and high heat.

Technical Abstract: Soybean seed is a major source of protein, oil, carbohydrates, isoflavones, and minerals for human and animal nutrition. Soybean seed contains approximately 40% protein, 20% oil, and 33% carbohydrates, 9% crude fiber. About one-third of the world's edible oils and two-thirds of its protein meal are derived from soybean seed. Thus, improving soybean seed quality and composition is a key to improving human and animal nutrition. Soybean seed quality refers to germination, viability, and vigor, of which impact yield. Seed composition refers to seed constituents including protein, oil, fatty acids, carbohydrates, isoflavones, and minerals, which determine seed nutritional value. Seed quality and composition are known to be genetically controlled, and significant variability in seed quality and composition exist in the gene pool. The physiological and biochemical mechanisms of this variability are not understood, yet the quality and composition components have been shown to be significantly influenced by genotype, environment, management practices, and their interactions. Understanding the interaction of these factors and how they impact seed quality and composition is crucial for maintaining high yield and quality. Current research showed that genotype, temperature, irrigation, soybean maturity, conventional tillage vs. no-tillage, crop rotation, and disease, and herbicide management significantly affect seed quality and alter seed composition constituents, especially protein, oil, oleic acid, linolenic acid, sugars, isoflavones, and minerals. This review highlights the current research on seed quality and composition as influenced by genotype, environment, and management practices, and their interactions. This information is beneficial for soybean breeders This information is beneficial for soybean breeders to develop and release cultivars to suit specific target locations to grow new value-added soybeans or select for specific seed composition qualities under environmental stress factors of drought and high heat.