Submitted to: Encyclopedia of Grain Science
Publication Type: Book / Chapter
Publication Acceptance Date: October 22, 2003
Publication Date: September 13, 2004
Citation: Palmer, R.G. 2004. Soybean:Germplasm, Breeding and Genetics. In: Wrigley, C., Corke, H. and Walker, C. (eds.) Encyclopedia of Grain Science. Elsevier Science Ltd. London, UK. p.136-146. Interpretive Summary: The earliest archeological remains of the cultivated soybean date from 770-476 B.C. in China. Soybean were introduced into the United States in the 1770s and were initially used as a forage crop. The early soybean cultivars were plant introductions or selections from plant introductions. The first U.S. cultivar selected from among progenies resulting from sexual hybridization was released in 1939. Now most cultivars are developed from crossing very good cultivars (or breeding lines) with different very good cultivars (or breeding lines). Plant introductions are used only as sources for specific traits, e.g., resistance to a particular disease. Soybean breeders make use of off-season nurseries (growing areas) such as Puerto Rico, Hawaii, or South America to speed up development of new cultivars. Genetics plays an important role in soybean breeding. The inheritance of a trait, e.g., disease resistance, seed color, etc. are important characteristics to select for in breeding. Different objectives are necessary because soybean is used for food, feed, and industrial applications. Molecular genetics will play an even more important role in improving the quality and quantity of soybean yields. Breeding and genetics are necessary to make advances in soybean improvement for the consumer. The seedsman, growers, and consumers will benefit for this research.
Technical Abstract: The development of soybean cultivars is an integrated process of germplasm selections, breeding methodologies, and genetic manipulations. In this general review chapter, germplasm within the genus Glycine is summarized by country and maturity group. Examples are given where germplasm (plant introductions) have been used directly to transfer a trait (usually a qualitative trait) that resulted in an improved cultivar. Breeding methods are described which give the advantages and disadvantages of each method. Testing in multiple years and environments (locations) within years is critical to identify the superior cultivars. Genetics (qualitative, quantitative, and molecular) are used to identify germplasm and to select high-yielding agronomic lines. For future cultivar development, the traditional procedures in partnership with transformation, functional genomics, etc. will be used to broaden the germplasm base, to hasten cultivar development, and to improve both the quality and quantity of soybean cultivars. The consumer is the beneficiary.