Fig. 1From: Morphological, physiological, and transcriptional responses to low nitrogen stress in Populus deltoides Marsh. clones with contrasting nitrogen use efficiencyEffects of low N stress on growth traits of N-efficient (A-1, A-2, and A-3) and N-inefficient (C-1, C-2, and C-3) genotypes. Different letters above the column indicate significant differences between groups (p < 0.05). (A) Height after treatment (Height-n, Hn); (B) Ground diameter after treatment (Ground diameter-n, GDn); (C) Fresh weight of the stem (SFW); (D) Fresh weight of the root (RFW); (E) Fresh weight of the leaf (LFW)Back to article page