Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 6/3/2002
Publication Date: 6/3/2002
Citation: Saha, S., Stelly, D.M., Gutierrez, O.A., Jenkins, J.N., McCarty Jr., J.C., Cantrell, R.G., Percy, R.G., Raska, D.A. 2002. Chromosome substitution lines in cotton improvement. Cotton Science. 14(S): 78. Interpretive Summary: Not required.
Technical Abstract: Tetraploid species such as G. barbadense, G. tomentosum, and G. mustelinum are reservoirs of genes for biotic stress resistance and for improved agronomic and fiber traits. Attempts to incorporate genes from wild species into Upland have not generally achieved stable introgression. We initiated a plan to develop a set of backcrossed chromosome substitution lines covering about 80% of the genome in Upland cotton using G. barbadense, G. tomentosum, and G. mustelinum, respectively, as donor species. We used monosomic and monotelodisomic hypoaneuploid G. hirsutum stocks of the Cotton Cytogenetics Collection to develop euploid backcrossed chromosome substitution lines from G. barbadense for chromosomes 1, 2, 4, 6, 7, 16, 17, 18, 25, 5L, 11L, 12L, 14L, 15L, 22L, 22S and 26S, respectively (L= long arm, S=short arm). These lines are genetically similar except that each differs by the replacement of a specific homologous pair of chromosomes or chromosome arms from G. barbadense into G. hirsutum. They provided an unique opportunity to map about 140 SSR markers to 21 different chromosomes by deficiency analysis. These chromosome substitution lines were also crossed with G. hirsutum (TM-1) to create chromosome-specific F1 hybrids. Self-progeny (F2) populations were used to evaluate effects of the substituted chromosome that underwent recombination and segregation therein. F2 families and parental lines were evaluated for agronomic and fiber data from bulk-sample analysis of field trials at three locations in the USA. This provided an opportunity to dissect complex fiber and agronomic traits for individual chromosomes. These lines also initiated the disruption of linkage blocks spanning desirable and undesirable alleles, some of which cotton breeders would likely find difficult to remove using conventional breeding methods. Trait analyses suggested that chromosomes H18, 22L and 22S were associated with an increase of lint percent as these lines produced higher lint percent than both of the parents. We observed that F2 hybrid lines specific to H25 affected micronaire and fiber strength. We are also developing aneuploid chromosome substitution lines in Upland cotton (TM-1) for chromosome 1, 2, 3, 4, 6, 9, 10, 14, 15, 16, 18, 22, 25 of G. tomentosum. This species is one of the most heat-resistant species in the genus.