Submitted to: Genetics and Genomics of Cotton
Publication Type: Book / Chapter
Publication Acceptance Date: 9/1/2007
Publication Date: 4/1/2009
Citation: Percy, R.G. 2009. The worldwide gene pool of Gossypium barbadense L. and its improvement. In Paterson, A.H., editor. Genetics and genomics of cotton. Springer, New York, pp. 53-68. Interpretive Summary: Germplasm resources provide the natural variability that is essiential for the continued genetic improvement of cotton. This book chapter presents a concise survey of the origins and development of improved Gossypium barbadense germplasm, beginning with Sea Island cottons, then the development of Egyptian and American Pima germplasm, and finally describing the development of Peruvian, Australian, and Israeli extra-long staple cottons. The genetic variability occurring in improved and unimproved G. barbadense gene pools is discussed, as are the contributions to variability made by introgression from upland cotton, G. hirsutum. The G. barbadense holdings in the USDA-ARS national collection are described and compared to genetic variability in improved germplasm pools. Recognition and of the structure of genetic variability within the species is crucial to efficient utilization of germplasm resources in broadening the genetic base of improved Pima cotton. expanding the genetic another collection, and among public cotton researchers. The U.S. collection is presently the largest collection worldwide, and with 4,106 accessions being distributed in 2006, is a widely used resource. The characterization and evaluation of materials held within the collection has been primarily a collaborative effort of the collection curators and public researchers. Unique genetic populations created by the public breeding and genetics research community also contribute significantly to maintaining genetic variability within cotton. Future progress in cotton improvement depends upon maintaining variability in germplasm collections and in public research programs.
Technical Abstract: This book chapter describes the improved and unimproved gene pools of Gossypium barbadense. Section one discusses the taxonomic and geographic structure of species diversity. Section two describes the origin and development of modern improved germplasm pools, beginning with Sea Island cottons developed in the Caribbean and the coastal Southeast of the United States in the late 18th century. The origins and development of the Egyptian and Amercian Pima germplasm pools are sketched. Finally, smaller but significant gene pools created in Peru, Israel, and Australia are discussed. The role of interspecific introgression with G. hirsutum in broadening the improved germplasm pool is noted. In section three, unimproved genetic resources in situ and in germplasm collections are examined.