Twenty-Five Years of Introgression Breeding through Interspecific Hybridization Between Gossypium Hirsutum and G. barbadense

This presentation will summarize my 25 years of experience in interspecific breeding between Upland and Pima cotton. In the mid-1980's, I employed interspecific crossing between Upland and Pima to introduce desirable genes for resistance to spider mites and Verticillium wilt from Pima to Upland cotton. Then, breeding objectives were expanded to include fiber quality, sub-okra leaf type and heterosis. This resulted in the development of high-yielding breeding lines with sub-okra leaf or cleistagamous flowers, and lines with high fiber quality. Since the early 2000's, molecular markers and gene expression profiling have been used to identify quantitative trait loci or differential expressed genes in Pima cotton or introgressed population. In the meanwhile, new introgressed lines with higher yield potential and/or better fiber quality than Upland cotton parents have been developed, indicating a simultaneous introduction of desirable genes for yield and fiber quality into Upland cotton. Tolerance to drought and salt stresses, and Verticillim wilt has also been evaluated in these introgressed lines. The presentation will report some of the major achievements and also discuss challenges in Upland x Pima breeding.