ABSTRACT

The exceptional fiber length, strength and fineness of Pima and Sea Island cotton (Gossypium barbadense) give it a 30% to 50% price advantage over the more widely grown Upland cotton (G. hirsutum) because of its superior spinning and manufacturing performance. Attempts to incorporate genes from G. barbadense into Upland have generally not achieved stable introgression of the G. barbadense fiber properties. Associated with these attempts have been poor agronomic qualities of the progeny, distorted segregation, sterility, and limited recombination due to incompatibility between the genomes. An alternative approach to introgress G. barbadense fiber quality genes into Upland cotton would be to use backcrossed alien chromosome substitution lines. The Texas Agricultural Experiment Station, the Agricultural Research Service of the United States Department of Agriculture, and the Mississippi Agricultural and Forestry Experiment Station announce the release of 17 unique germplasm lines of backcrossed chromosome substitution lines of different Gossypium barbadense chromosomes in a G. hirsutum genetic background. This material forms a unique set of germplasm lines which are genetically similar except that each differsby the replacement of a specific homologous pair of chromosomes or chromosome segments from 3-79 (G. barbadense) into TM-1, Upland cotton (G. hirsutum). Using an integrated approach of cytological and conventional breeding methods by hypoaneuploid-based backcross chromosome substitution, we have replaced individual Gossypium hirsutum (‘TM-1’) chromosome pairs with the respective G. barbadense (‘3-79’) chromosome pairs. This material forms a unique set of germplasm lines which are genetically similar except that each differsby the replacement of a specific homologous pair of chromosomes or chromosome segments from 3-79 (G. barbadense) into TM-1, Upland cotton (G. hirsutum). Our preliminary results from crossing program using these lines as one of the parents with TM-1 showed that these lines are very useful in mapping important traits including QTLs and improving germplasm for fiber and agronomic properties. These germplasm lines were developed and evaluated by, D.M. Stelly and W. Raska of Texas A&M University, S. Saha, J.N. Jenkins, J.C. McCarty, and O.A. Gutierrez of the USDA/ARS, Mississippi State, MS in a collaborative research program.