Genetic Diversity in the U.S. Cotton Germplasm Collection As Revealed by SSR Markers

A comprehensive knowledge of the genetic diversity within the U.S. Gossypium Germplasm Collection is necessary to achieve its most effective utilization and the greatest efficiency in its maintenance.  In this report we provide preliminary information upon the diversity of the collection as detected by a 105 SSR marker core set.  This marker set was used to genotype 2,256 accessions representing 31 species of Gossypium, or approximately a quarter of the collection.  Comparisons are made of diversity among and within accessions, among and within species, and between wild and cultivated accessions of commercial species.