Chromosome substitution lines with improved essential mineral nutrients and fiber quality traits in Upland cotton

Introgression of donor germplasm from Gossypium tetraploid species into Upland cotton (G. hirsutum L.) would help alleviate the constricted genetic base of Upland cotton and increase opportunities for genetic improvement. The objective of this research was to determine whether the mineral nutrition and fiber quality of cotton are affected by and might be improved using 11 quasi-isogenic BC5Sn interspecific chromosome substitution (CS) lines of Upland cotton. The CS lines were bred previously for disomic replacement of Upland cotton chromosomes 01, 04, 07, 15 (part), and 18 by homologs from G. barbadense L. and G. tomentosum Nutt. ex Seem., and another for part of Upland chromosome 08 by G. tomentosum. The CS lines were grown in two fields along with a related Upland inbred, TM-1. Leaf mineral nutrition of the CS lines was measured based on samples taken two weeks after flowering. Fiber quality was based on bolls hand-picked at harvest. CS lines involving 1 and 18 were associated with leaf nutrient improvement. CS-B18 improved leaf N, P, K, and Zn relative to TM-1. All fiber quality traits were affected by CS lines, but none led to more than two fiber quality improvements. CS-B15Lo and CS-B18 improved fiber strength and elongation, whereas CS-T15Lo improved fiber elongation and yellow index. Some leaf mineral and fiber quality traits exhibited positive correlations. Overall results suggest these chromosome substitutions broaden the genetic base and allow for potential enhancement of leaf mineral nutrition and fiber quality of Upland cotton.