Genetic Effects of Thirteen Gossypium barbadense L. Chromosome Substitution Lines in Topcrosses with Upland Cotton Cultivars: II. Fiber Quality Traits

Thirteen chromosome substitution lines (CS-B) lines with individual 3-79 Gossypium barbadense L. chromosome or arms substituted into TM-1, G. hirsutum L., were crossed with five Upland cultivars and additive and dominance effects for fiber micronaire, elongation, length, and strength were measured over four environments. Additive genetic effects were considerably larger than dominance or environmental interaction effects. Fiber strength of 3-79 and FM966 were 282 and 240 kN m kg-1, respectively. FM966 had greater additive effects for fiber length (1.13 mm) and strength (12.90 kN m kg-1) than any CS-B line; however, CS-B25 had the greatest additive effects (8.97 kN m kg-1) for strength among CS-B lines. The greatest negative additive effect for fiber length was -1.29 mm (CS-B22sh). Although several CS-B lines had negative additive effects on strength, none was more negative than TM-1 (-5.31 kN m kg-1). CS-B02 and CS-B25 had additive effects on strength of 2.36 and 8.97 kN m kg-1. SG747 had the greatest negative additive effect (-12.13 kN m kg-1) for strength among cultivars and CS-B lines. CS-B07 and CS-B18 had negative additive effects for fiber strength but had significant and positive dominance effects with FM966. When individual CS-B lines were crossed with elite cultivars beneficial alleles for fiber properties were uncovered on specific chromosomes or chromosome arms that should aid introgression of alleles from 3-79 into Upland.