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The objective of this study was to identify mutants of upland cottonseed (Gossypium hirsutum L.) with reduced levels of palmitic acid (C16:0) in the seed. The five parental populations that had been exposed to Ethyl MethaneSulfonate in 1997 or 2002 were initially screened for either herbicide tolerance or divergent fiber quality. Fatty acid composition were determined for five seed bulks from 140 M5 mutant lines in 2009 and 100 M6 partial seeds in 2010. Mutants with reduced levels of palmitic acid levels were isolated from TAM 94L-25 (PI 631440), Acala 1517-99 (Reg. No. CV-115, PI 612326) and TTU SCM3-7-3 (Reg. No.GS-4, PI 657942). Thirteen M6 single seeds with reduced levels of palmitic acid (17.9–19.6%) were intercrossed in the greenhouse. Ten of the single seed selections were designated as potential male parents and randomly crossed to three potential female parents to generate F1 plants and 21 F2 populations for allele testing. Based on these tests, five F2 populations with reduced levels of low palmitic acid, were selected for further evaluation. The development of mutant lines with reduced levels of palmitic acid in upland cotton was submitted for proprietary protection under U.S. Patent No. 20160222399.

This research evaluated the potential for using sexual crosses for genetic improvement of fiber yield, lint percent, AFIS fiber quality, and fiber initiation of two naked-tufted mutants of cotton (Gossypium hirsutum L.). The naked tufted lines were crossed with ten fuzzy breeding lines to generate 10 F2 populations. The F2 distributions were tested with Chi Square for Goodness of Fit to two monogenic and two digenetic segregation ratios. Five of the six F2 populations made with Atlas-NS-129 segregated as either a single dominant gene (3 Naked-tufted: 1 fuzzy) or as two dominant genes (9 Naked-tufted: 7 fuzzy). Three of the four F2 populations made with SC 9023-ns-57 segregated as either a single recessive gene (3 Fuzzy: 1 naked-tufted) or as duplicate recessive genes (9 Fuzzy: 7 naked-tufted). However, the F2 populations when crossed with the Fuzzy line of Tejas 48 showed a reversal of dominance. The F2 population of Atlas-NS-129 X Tejas 48 fit a 9 Fuzzy: 7 naked tufted ratio expected of two recessive genes. The F2 population of the cross of SC 9023-ns X Tejas 48 fit a 3 Naked-tufted: 1 fuzzy ratio expected of a single dominant gene. Additional studies will be necessary to fully determine the number of gene(s) and the expected phenotypic ratios of individual naked-tufted mutants in crosses with fuzzy seeded breeding lines. Eight of the F2 and F3 populations were also evaluated for lint yield, lint percent and AFIS fiber quality traits. The F2 and F3 populations of the cross of Atlas-NS-129 X Holland 338 produced the highest average lint yields (1089 kg ha−1) as well as excellent fiber quality. These data indicate that it may be possible to develop relatively high yielding naked tufted cultivars by crossing these mutant lines with elite higher yielding breeding lines.