Plant, Animal & Microbe Genomes X Conference Plant, Animal & Microbe Genomes X ConferenceJanuary 12-16, 2002
Town & Country Convention Center
San Diego, CA
Workshop: Cotton
The exceptional fiber length, strength and fineness of Pima cotton (Gossypium barbadense L.) gives it a 30 to 50% price advantage over the more widely grown Upland cotton (G. hirsutum L.) 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. A non-conventional approach to introgress G. barbadense fiber quality genes into an Upland background is the development of chromosome substitution lines. We developed a set of backcrossed chromosome substitution lines for different chromosomes covering about 80% of the genome. These lines are largely identical, except that each differs by the replacement of a specific homologous pair of chromosomes from Pima 3-79 (G. barbadense) into Upland. Precluded of the opportunity for homologous recombination during development, each substitution is known to cover the respective chromosome comprehensively. Observation of different chromosome substitution lines in such a uniform genetic background also provided a unique opportunity to map 145 SSR markers on 21 different chromosomes by scientists in different labs. We recently initiated a project to develop analogous interspecific aneuploid chromosome substitution lines in Upland cotton of G. tomentosum Seem., one of the most heat-resistant species of the genus and the source of the nectariless trait. Such materials offer considerable utility for structural genomic, functional genomic, and proteomic investigations.