Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 1/10/2004
Publication Date: 1/10/2004
Citation: Stelly, D.M., Saha, S., Raskal, D.A., Wu, J., Jenkins, J.N., McCarty Jr., J.C., Gutierrez, O.A., Percy, R.G., Gardunial, B., Dighel, N. 2004. Chromosome-specific resources for germplasm introgression and genomics in Gossypium [abstract]. Plant and Animal Genomes XII Conference Proceedings. Paper no. W187.
Technical Abstract: Germplasm introgression and structural genomics are inextricably linked in cotton. In several breeding approaches, common plant materials are being used to simultaneously harness higher rates of marker polymorphism, genetically diversify elite germplasm, and improve resources for genetic analysis and genetic improvement. The information and germplasm derived from chromosome-specific manipulations are highly complementary to those from other approaches. Each chromosome-specific manipulation offers a large-scale approach to mapping and introgression, probably involving ca. 1000-4000 genes. These have involved several types of G. hirsutum hypoaneuploids, including primary monosomics, monotelodisomics, tertiary monosomics and duplication-deficients". The "Monosome Walk" and "TTT Shuffle" chromosome manipulation methods will be described as they are somewhat unorthodox and have proven invaluable in extending genome coverage. Hemizygosity of F1 generation hypoaneuploids has enabled localization linkage groups and, in some cases, their orientation, placement of centromeres, and translocation breakpoint localization. The F1s greatly facilitate integration multiple linkage maps and coordination of research across laboratories. DNA panels are being assembled for distribution. Backcrossing of BCnF1 generations to G. hirsutum hypoaneuploids has allowed telomere-to-telomere alien germplasm introgression on a chromosome-specific basis, followed by selfing to recover respective disomic substitution euploids. By contrast, other approaches typically suffer extreme loss of alien germplasm during introgression and/or cannot exclude the possibility of cryptic recombination, e.g., between molecular markers. Differences among disomic substitutions are encouraging efforts aimed at high-resolution QTL identification through the development and replicated experimental testing of chromosome-specific RILs.