|Percival Jr, Albert|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 12/6/2000
Publication Date: 1/13/2001
Technical Abstract: The USDA Cotton Germplasm Collection contains 7,157 accessions, and it represents 2,211 obsolete G. hirsutum cultivars, 2,102 exotic G. hirsutum races, 1,333 G. barbadense that include obsolete and exotic types, 969 Asiatics, and 542 wild species. Prior characterization of the Gossypium accessions is focused on distinguishing among them and not one of identifying and elimination redundancy. When accessions from other collections, such as the Russian collection (over 6,000 accessions), are added, questions of duplication or redundancy become important considerations. The development of cotton genomics provides new and powerful tools that can effectively characterize the Gossypium germplasm. We began with 280 cotton accessions with an initial set of 100 DNA marker loci. The accessions were selected for their representation from different gene pools or sources. Among them were 151 G. hirsutum accessions (30 exotic, 41 obsolete, and 80 Russian) and 126 G. barbadense accessions (67 from the U.S. Collection and 59 from Russia); also included 3 Asiatic cottons; together with TM-1 and 3-79, two genetic standards of AD genomes. The 100 DNA markers, mostly simple sequence repeats (SSRs), were selected from the cotton genetic map representing each of the cotton chromosomes or linkage groups. DNA profiles of 280 Gossypium accessions were generated with automated genetic analyzers, and genetic markers were capable of detecting polymorphism among G. hirsutum accessions. Results of cluster analysis indicated not only the separation of three major groups (G. hirsutum, G. barbadense, and Asiatic cottons), but also the separation of each of two major groups (G. hirsutum and G. barbadense) into more than a dozen subgroups. The resulting unique Gossypium accessions will be subjected to further characterization with additional 100 DNA markers selected for the best ability to describe the germplasm. The selected core DNA markers will be extended to the characterization of additional hundreds, or even thousands of the Gossypium germplasm.