|Stelly, David - TEXAS A&M UNIVERSITY|
|Raska, Wayne - TEXAS A&M UNIVERSITY|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 11, 2005
Publication Date: November 1, 2005
Citation: Stelly, D.M., Saha, S., Raska, D.A., Jenkins, J.N., McCarty Jr., J.C., Gutierrez, O.A. 2005. Registration of 17 upland (Gossypium hirsutum) cotton germplasm lines disomic for different G. barbadense chromosome or arm substitutions. Crop Science. 45:2663-2665. Interpretive Summary: Pima and Sea Island cotton (Gossypium barbadense) possess superior fiber properties and give it a price advantage over the more widely grown Upland cotton (G. hirsutum). Historically, cotton breeders have faced many challenges in their attempts to introgress G. barbadense genes into Upland cotton due to incompatibility between the genomes. Associated with these attempts at introgression have been poor agronomic qualities of the progeny, distorted segregation, sterility, mote formation, and limited recombination due to incompatability between the genomes. An alternative approach to introgress G. barbadense fiber quality genes into an Upland background would be to rely on chromosome substitution lines rather than trying to achieve stable recombination between the partially incompatible genomes. We have developed a set of seventeen stable backcrossed G. barbadense (3-79) chromosome substitution lines (CS-B), many of which were not previously available in G. hirsutum (TM-1) background. These lines are near-isogenic, with the exception of the substituted chromosome or chromosome segment from 3-79. These CS-B lines were developed in a collaborative research program by the Texas Agricultural Experiment Station, the Agricultural Research Service of the United States Department of Agriculture, and the Mississippi Agricultural and Forestry Experiment Station. Breeders typically rely on whole genome strategy in conventional breeding methods of interspecific introgression. This strategy often results in progenies containing large numbers of alien genes, some linked and some independently inherited. However, detection of the progenies with desirable alien genes is extremely difficult. Controlled interspecific introgression of G. hirsutum with G. barbadense through the CS-B lines based on individual chromosomes or chromosome segments provides an opportunity of an effective way of cotton improvement. Moreover, comparative analysis of different traits in the CS-B lines in a uniform genetic background allows detection of genetic effects from all genes of the substituted chromosome or chromosome segment.
Technical Abstract: Seventeen unique germplasm lines were developed by backcross chromosome substitution of different Gossypium barbadense chromosomes into a G. hirsutum genetic background by the Texas Agricultural Experiment Station, the Agricultural Research Service of the United States Department of Agriculture, and the Mississippi Agricultural and Forestry Experiment Station. The backcrossed chromosome substitution lines (CS-B) are genetically similar except that each differs by the replacement of a specific homologous pair of chromosomes or chromosome segments from the 3-79 (G. barbadense) into TM-1, Upland cotton (G. hirsutum). By hypoaneuploid-based backcross chromosome substitution, we have replaced individual TM-1 chromosome pairs with their respective 3-79 chromosome pairs and largely reconstituted the other G. hirsutum chromosomes. The cytologically identified euploid BC5F1 plant of the CS-B line was selfed to establish euploid BC5S1 lines. These CS-B lines are being released because attempts to incorporate genes from G. barbadense for exceptional fiber length, strength and fineness into Upland have generally not achieved stable introgression. Poor agronomic qualities of the progeny, distorted segregation, sterility, and limited recombination due to incompatibility between the genomes have been associated with previous attempts to incorporate genes from G. barbadense. An alternative approach to introgress G. barbadense genes into Upland cotton is to develop and use backcross derived alien chromosome substitution lines.