Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 10/10/2004
Publication Date: 10/10/2004
Citation: Saha, S., Jenkins, J.N., Wu, J., McCarty Jr., J.C., Percy, R.G., Cantrell, R.G., Stelly, D.M. 2004. Cytogenetic resources in dissecting complex QTLs and enhancing germplasm in upland cotton. International Cotton Genome Initiative ICG-2004 Workshop Proceedings. p. 81. Interpretive Summary: None required.
Technical Abstract: Stagnant yield, declining fiber quality, threat from biotic and abiotic stresses limit the profitability in world cotton production. Two major limitations to the genetic improvement of cotton are the lack of information about genes that control quantitative traits (QTL) such as fiber yield or fiber quality, and the need for more extensive usage of diverse germplasm. The narrow germplasm base in Upland cotton signifies the need for new genetic resources and novel methods to improve genetic variability in Upland cotton (G. hirsutum L.). We have developed 14 backcrossed chromosomal substitution (CS-B) lines which were used to dissect the genetic effects of quantitative traits associated with specific chromosomes or arms. Fourteen cotton lines with specific chromosomes or chromosome arms from G. barbadense L. substituted into G. hirsutum (CS-B) were crossed with the recurrent parent and data collected in five diverse environments. Data for chromosome-specific F2s and their parental lines were analyzed using the additive and dominance (AD) genetic model. Results showed that both additive and dominance effect were significant for most of the traits. CS-B25 had additive effects increasing fiber strength and fiber length and decreasing micronaire and CS-B 16 and CS-B 18 had additive effects related to reduced yields. The heterozygous dominance chromosomal effect between some CS-B lines were different from the homozygous dominance effect for the corresponding CS-B lines. The results provided information on the association of specific chromosomes with genes for agronomic and fiber traits. These new genomic resources will provide an additional route to Upland cotton improvement and will enable development of chromosome-specific recombinant inbred lines for higher resolution mapping.