The effect of two marker loci selection on short fiber content (SFC) (panel A), fiber bundle strength (STR) (panel B), upper half mean fiber length (UHM) (panel C) and length uniformity (UI) (panel D). Based on the genotypes of two marker loci, i.e., C2-0114a on Chr.07 and CM0066a on Chr.16, the 275 RILs of Set 2 were divided into two groups: 1) RILs with favorable alleles at both loci (Favor in red) and 2) RILs with unfavorable alleles at both loci (Unfavor in black). The mean trait values of the two groups were shown in red and black circle, respectively. The trait value difference between the two groups was significant at p < 0.001. Y axis for SFC: %, STR: g/tex, UHM: mm, and UI: %.