Submitted to: Euphytica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/9/2008
Publication Date: 1/1/2009
Citation: Wu, J., Gutierrez, O. A., Jenkins, J.N., McCarty Jr., J.C., Zhu, J. 2009. Quantitative analysis and QTL mapping for agronomic and fiber traits in an RI population of Upland cotton. Euphytica. 165:231-245. Interpretive Summary: Very little is known about the association of molecular markers with important quantitative traits for yield and fiber quality in upland cotton. Precisely mapping genetic factors contributing to these important traits in cotton should improve the process of molecular breeding. We determined 56 QTL's associated with 14 agronomic and fiber traits are located on 17 chromosomes. Chromosomes 3, 5, 12, 13, 14, 16, 20, and 26 harbor important QTL's for both yield and fiber quality. Since this RI population was developed from an intraspecific cross within upland cotton, these QTL's should be useful for marker assisted selection procedures for improving breeding efficiency in cotton line development.
Technical Abstract: In this present study, we evaluated a RI population including 188 RI lines developed from 94 F2-derived families and their two parental lines, ‘HS 46’ and MARCABUCAG8US-1-88 (Gossypium hirsutum L.), at Mississippi State, MS, for two years. Fourteen agronomic and fiber traits were measured. One hundred forty-one (141) polymorphic SSR markers were screened for this population and 125 markers were used to construct a linkage map. Quantitative genetic analysis showed that the genotypic effects accounted for more than 20% of the phenotypic variation for all traits except fiber perimeter (18%). The QTL's detected for these traits showed consistency with the variance component analysis. Fifty-six QTL's (LOD>3.0) associated with 14 agronomic and fiber traits were located on 17 chromosomes. One QTL associated with fiber elongation was located on linkage group LGU01. Nine chromosomes in sub-A genome harbored 27 QTL's with 10 associated with agronomic traits and 17 with fiber traits. Eight chromosomes in sub-D genome harbored 29 QTL's with 13 associated with agronomic traits and 16 with fiber traits. The QTL number for each of five agronomic traits (4.6 QTL's per trait) was slightly higher than that of nine fiber traits (3.7 QTL's per trait). Chromosomes 3, 5, 12, 13, 14, 16, 20, and 26 harbor important QTL's for both yield and fiber quality compared to the other chromosomes. The QTL results were also compared with many other studies. Since this RI population was developed from an intraspecific cross within upland cotton, these QTL's should be useful for marker assisted selection procedures for improving breeding efficiency in cotton line development.