|Wu, Jixiang - MISSISSIPPI STATE UNIV|
|Stelly, D - TEXAS A&M UNIVERSITY|
|Raska, D - TEXAS A&M UNIVERSITY|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 21, 2004
Publication Date: December 1, 2004
Citation: Saha, S., Wu, J., Jenkins, J.N., McCarty Jr., J.C., Gutierrez, O.A., Stelly, D.M., Percy, R.G., Raska, D.A. 2004. Effect of chromosome substitutions from Gossypium hirsutum L. 3-79 into G. hirsutum L. TM-1 on agronomic and fiber traits. Journal of Crop Science. 8:162-169. Interpretive Summary: Two major economic forces driving the global cotton market are competition from synthetic fibers and technological changes in the textile industry that require improved fiber quality. To improve fiber quality while maintaining the superior agronomic and yield properties of Upland cottons requires genetically effective approaches and a greater understanding of the genetics of fiber quality. We have developed a set of stable backcrossed G. barbadense (3-79) chromosome substitution lines (CS-B lines), many of which were not available previously. The CS-B lines are genetically identical, except that each differs by the replacement of a specific homologus pair of chromosomes from 3-79 (G. barbadense). Observation and measurement of different CS-B lines in such a uniform genetic background allowed us to detect the effect of the group of genes that a specific chromosome carries. Thirteen euploid (2n=52) backcrossed chromosome substitution lines (CS-B) and their parents were evaluated for agronomic and fiber properties in replicated tests at three locations in Mississippi and Arizona. We detected chromosomal locations of several agronomic and fiber traits. Chromosomes 16, 18, 5sh, 22Lo and 22sh of 3-79 were associated with significantly improved lint percentage in CS-B lines compared to TM-1. Chromosome 25 of 3-79 was associated with reduced micronaire and increased fiber strength compared to TM-1. CS-B 14sh, 15sh, and 25 were associated with increased fiber length, compared to TM-1. Five of the substituted chromosomes or chromosome arms (16, 18, 5sh, 14sh, 22sh) had significantly less seed cotton yield than TM-1. Six substituted chromosomes or arms (16, 17, 18, 25, 14sh, and 22sh) were associated with lower lint cotton yield than TM-1. The CS-B lines provided valuable information about the chromosomal locations of important fiber and agronomic traits and showed the potential for improving some important fiber traits in an Upland background.
Technical Abstract: Pima cottons (Gossypium barbadense L.) possess fiber properties that are superior to the more widely grown Upland cottons (G. hirsutum). Attempts to incorporate genes for improved fiber properties from Pima into Upland have generally not achieved stable introgression, due to incompatibility between the genomes. We have developed a set of stable, backcrossed G. barbadense (3-79) chromosome or chromosome arm substitution lines in a G. hirsutum (TM-1) background. Backcrossed substitution lines are near-isogenic, with the exception of the substituted chromosome or chromosome segment from 3-79. Thus, traits of backcrossed chromosome substitution (CS-B) lines that varied significantly from the TM-1 parent could be attributed to genes associated with the substituted chromosome and/or its interaction with the other 25 chromosomes from TM-1. In 2002, seeds from cytological-identified euploid (normal 26 II chromosomes) C-SB lines for 13 different chromosomes or chromosome arms, as well as the TM-1 and 3-79 parents, were planted in replicated tests at two locations in Mississippi and one location in Arizona for evaluation of agronomic and fiber properties. Chromosomes 16, 18, 5sh, 14sh and 22sh of 3-79 were associated with reductions in seed cotton and all, except 5sh, with reduced lint yield in the TM-1 background compared to TM-1. Chromosomes 16, 18, 5sh, 22Lo and 22sh of 3-79 were associated with significantly improved lint percentage in CS-B lines compared to TM-1. The presence of chromosome 25 of 3-79 was associated with reduced micronaire and increased fiber strength compared to TM-1. Significantly reduced boll size was associated with all substituted chromosomes except 2, 4, and 6, compared to TM-1. CS-B 14sh, 15sh, and 25 were associated with increased fiber length, compared to TM-1. The CS-B lines provided information of association of specific chromosomes with important genes for agronomic and fiber traits. These new genomic resources will provide an additional route to Upland cotton improvement. Moreover, these new genomic resources will enable development of chromosome-specific recombinant inbred lines for higher resolution mapping and Upland cotton improvement.