FIGURE 5 Effects of drought stress on the ratio and size of root cross-section in the two cotton varieties. (A) Representative image of the root tissue size of ”Guoxin 02” under drought stress. Statistical analysis of (B) stele/whole ratio, (C) cortex/stele ratio, and (D) lacunae/cortex ratio at the 3 cm, 6 cm, 9 cm, and 12 segments cm from the root tips of ”Guoxin 02” and ”Ji 228”. NS, no-stress; DS, drought stress; C, varieties; D, drought. Error bars represent standard errors of the means. P >0.05, no significance (ns); P <0.01 significant difference (**). Different lowercase letters in the figure indicate significant differences between different root segments under the same treatment (P ≤ 0.05)