|Campbell, Benjamin - Todd|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 10/1/2011
Publication Date: 11/7/2011
Citation: Saha, S., Stelly, D.M., Raska, D., Wu, J., Jenkins, J.N., McCarty Jr., J.C., Abdusalom, M., Gotmare, V., Abdurakhmonov, I.Y., Campbell, B.T. 2011. Interspecific chromosome substitution lines from Gossypium barbadense and G. tomentosum in Upland cotton improvement. Proceedings World Cotton Research Conference-5. p. 129. Interpretive Summary:
Technical Abstract: The merit of interspecific germplasm introgression has been well appreciated in many crop species, but it has not been exploited well in Upland cotton improvement. Wide-cross introgression typically requires considerable time and effort to circumvent and overcome biological, genetic, and cytogenetic hurdles. Results from previous studies indicate that synteny and colinearity are at least grossly conserved among the five tetraploid species, suggesting that there are few major cytostructural barriers to interspecific introgression among the tetraploid species. Irrespective of the biological basis, genetic limitations are manifested by the significant levels of F2 breakdown among interspecific crosses, and these seem to involve factors widely dispersed at the whole-genome level, and to have largely thwarted attempts at conventional germplasm introgression. A non-conventional method of interspecific germplasm introgression is chromosome substitution (CS). The goal of this project is to develop chromosome substistution lines from the other tetraploid species in Gossypium hirsutum. The chromosome substitution lines are genetically similar to TM-1, an Upland cotton (G. hirsutum) genetic standard, and to each other, except that each line differs by the replacement of a specific homologous pair of chromosomes or chromosome segments from the donor species. In recent years, we have released several G. barbadense chromosome or chromosome arm substitution (CS-B) lines. Moreover, we have demonstrated that comparisons of the CS-B lines and derived F2, F3 family types, and topcrosses, can provide important information about associations with fiber and agronomic traits. Recently, we also have developed analogous chromosome substitution lines involving G. tomentosum ("CS-T" lines). In current research, some of the CS-T lines are being characterized, while others are still being synthesized. We are similarly developing monosomic or monotelodisomic chromosome substitution lines from G. mustelinum ("CS-M" lines). As a check on the final composition of some of the CS lines, we have undertaken efforts to screen them with chromosome-specific SSR markers. Most marker results were concordant but several were inconclusive or discordant. For the latter, we are investigating further to discern the underlying basis, which is likely an infrequent type(s) of event, and could be a procedural and/or biological in nature. Currently we are using many of these CS lines in the development of chromosome-specific recombinant inbred lines for high-resolution QTL definition. All of these materials will provide additional tools in genomic analysis and genetic improvement of Upland cotton. The genomic resources of CS lines will complement the conventional approaches of interspecific introgression in Upland cotton improvement.