Using High-Throughput Genotyping to Understand and Access Sorghum Diversity.

The U.S. National Plant Germplasm System collection of sorghum [Sorghum bicolor (L.) Moench] is comprised of over 40,000 accessions while other national and international collections cumulatively total more than 200,000 entries.  The mission of these networks of gene banks is to safeguard and utilize germplasm (and associated information) to ensure an abundant, safe, and inexpensive supply of food, feed, fiber, and energy.  With regard to safeguarding germplasm, high throughput genotyping is essential (in complement with other classical approaches) to providing insights on how and why diversity is represented in a crop in nature and where genetic gaps and redundancies exist in ex situ collections.  Moreover, high throughput genotyping also will be critical in structuring gene bank holdings and providing information that will serve as an intellectual and operational bridge for crop enhancement and breeding.

With impending climate change in the 21^st century, sorghum is likely to become a more important crop in the ever increasing semi-arid regions of the world.  Native to some of the most inhospitable environments, this cereal will be valued as we strive to increase sustainable production under water-, temperature-, and nutrient-challenged conditions.

In this presentation, we summarize recent activities focusing on genotyping-by-sequencing to establish agricultural, genetic, and evolutionary insights into the diffusion and use of sorghum as a crop.  In addition, the same technology is employed to understand how diversity is organized in both the genome and genepool.  We expect that this information ultimately will be useful to effectively discover and conserve useful genes and genotypes for the future.