Fig. 1

Effects of nitrogen content on winter wheat crop. a The shoot morphology, including crop height, leaf area per plant, specific leaf area, shoot fresh weight; b root morphology, including root length per plant, root surface area, root volume per plant, root fresh weight per plant; c root/shoot ratio; d net photosynthetic rate; e phenotypes, under normal nitrogen (N1) and nitrogen-deficient (N0) conditions. The root length per plant, root surface area, root volume per plant, root fresh weight per plant were the sum of all roots of one plant. Significance levels of differences between N0 and N1 group were estimated using the two-tailed t-test method. Different lowercase letters represent significant differences