Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 10/2/2000
Publication Date: 11/4/2000
Technical Abstract: As a major crop species and leading natural fiber crop in the world, cotton has a potentially broad genetic base, reflected in the collections of Gossypium species. Cotton breeders therefore have an opportunity to exploit and manipulate many thousand genes in the Gossypium reservoir. To positionally isolate genes in cotton and to physically map the cotton genome, high-quality libraries are needed that are comprised of bacterial artificial chromosome(BAC)clones containing large cotton DNA inserts. We have constructed three complementary BAC libraries(BamHI, EcoRI, and HindIII)from a Gl2**e-BC6 nearly isogenic line(NIL)of G. hirsutum acc. TM-1, a genetic standard of Upland cottons. The cloning vector of pECBAC1 was used in all three libraries(about equal genome coverage). The total number of BAC clones is 115,584, covering 7.2X haploid AD genome equivalents. The average size of DNA inserts is 143 Kb, with a range of 90 Kb to 210 Kb. Chloroplast clones consist of about 1.5% of the libraries. DNA markers, flanking the glandless cotton gene Gl2**e, were identified via linkage analysis of an F2 population derived from a cross between the TM-1 NILs(with and without Gl2**e). Such DNA markers have been used to screen the BAC libraries for the isolation of the Gl2**e gene to engineer the glandless cottonseed, and additional DNA markers are being developed from a contig assembled by fingerprinting two dozen positive BAC clones. The cotton BAC libraries also provide a rich resource for detailed cotton genomics research including marker development, physical mapping, comparative analysis, and germplasm characterization.