Efficacy of qFL‐chr1, a Quantitative Trait Locus for Fiber Length in Cotton (Gossypium spp.)

Abstract

In an earlier advanced‐backcross quantitative trait locus (QTL) analysis of an interspecific Gossypium hirsutum L. × Gossypium barbadense L. population, 28 fiber length QTLs were identified including qFL‐chr1 on chromosome 1 of the A‐subgenome. The G. barbadense allele at this QTL contributed to longer fibers and explained up to 24% of the phenotypic variance. To substantiate the association of this genomic region with fiber length, three BC3F2 plants heterozygous for the genetic markers that delineate the qFL‐chr1 QTL were selected to construct three independent populations of near‐isogenic introgression lines (NIILs). The efficacy of qFL‐chr1 was evaluated among 140 NIILs grown in 2 yr. The results support the positive effect of qFL‐chr1 on fiber length. A single NIIL, R01‐40‐08, had about 94.3% of recurrent genome composition and significantly longer fiber than the recurrent parent when grown in Nanjing, China. Therefore, in addition to confirming the efficacy of qFL‐chr1 to enhance fiber length, this work provides a valuable genetic resource for the improvement of cotton.