Conventional breeding techniques have been minimally successful in introgressing novel fiber quality traits of Gossypium barbadense L. into elite G. hirsutum L. cultivars. The Cotton Improvement Lab at Texas A&M AgriLife Research utilized Chromosome Substitution Lines (CSLs) to address the recalcitrant nature of the G. barbadense fiber traits. Sixteen CSLs, each having only one G. hirsutum chromosome replaced with a barbadense chromosome, were used in a Line by Tester (lxt) design to evaluate combining ability for fiber upper half mean length (UHML), strength (Str), Lint % (lint wt./seedcotton wt.*100), and Scwt yield (Seedcotton weight). Three upland testers were used, including an extra-long staple type, TAM 182-33, an extra strength upland type, TAM 06WE-621, and a high-yield cultivar, Tamcot 73. Fiber properties of parents and F1s developed by crossing each CSL with each tester were assessed by High Volume Instrument (HVI). Combining ability analysis of the HVI and yield data indicated CS-B25, CS-B18, CS-B02 and CS-B11sh as good general combiners for UHML, Str, Lint % and Scwt yield, respectively. Tamcot 73/CS-B01 was a good specific combiner for UHML and Scwt yield among all F1s. The F1s showed additive gene action for UHML, Str, Lint %, whereas yield displayed a dominance gene effect. The results indicate CSL potential in unlocking the beneficial alleles in G. barbadense and aid in the stable introgression of its superior fiber quality into G. hirsutum species.
