Submitted to: Soybean Research World Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: May 10, 2009
Publication Date: August 9, 2009
Citation: Nelson, R.L. 2009. Expanding Genetic Diversity to Increase Soybean Seed Yield [abstract]. In: Proceedings of the World Soybean Research Conference VIII,August 9-16, 2009, Beijing, China. 2009 CDROM. Technical Abstract: In the United States, fewer than 100 ancestral lines have contributed to currently grown cultivars and more than 50% of that contribution comes from only 5 lines. Based on national production statistics, the average rate of yield improvement from 1924 to 1978 is nearly identical to the rate of from 1978 to 2009 despite the many advances in plant breeding. Although much more than genetic gain is represented in such statistics and there is no evidence that breeding progress is not still being made, incorporating new germplasm will allow breeders to more fully utilize both the genetic diversity and the new genetic technology that is available. There are three distinct sources of diversity that are, at least genetically, readily available to soybean breeders. Glycine soja, wild soybean, has been consistently shown to be more genetically diverse that cultivated soybean, Glycine max, but very little is known about how much of that diversity may be economically useful. Successfully utilizing wild soybean germplasm has been very difficult. Primitive varieties from East Asia that predate scientific plant breeding are a second and more easily exploitable source of diversity. By numbers, this is the largest source and many of the negative factors present in the wild soybean have been removed. The third source is improved cultivars from other countries. Selectively choosing those that are most genetically distinct from domestic cultivars can provide highly useful parental lines. Examples of developing high yielding germplasm from each of these sources of diversity will be provided.