Fig. 1

Phenotypic diversity of 244 wheat accessions. A Frequency distributions and differences for PH, EPN, and GYA of the wheat accessions measured under LN and HN in 2018, 2019, 2020, and the BLUP across all three environments. PH: plant height, EPN: effective panicle number per unit area, GYA: grain yield per unit area. BLUP: Best linear unbiased predictions. Box edges represent the 0.25 and 0.75 quantiles with the median values shown by bold lines. Whiskers extend by no more than 1.5 times the interquartile range, and the remaining data are indicated by dots. P values were calculated with Student’s t test. B Frequency distribution histogram of zero mean normalized phenotypic values of PHR, EPNR, and GYAR in 2018, 2019, 2020, and BLUP. PHR: plant height ratio of the low to high nitrogen treatments (LN/HN); EPNR: effective panicle number ratio of LN/HN; GYAR: grain yield per unit area ratio of LN/HN; 2018, 2019, and 2020: the 2017–2018, 2018–2019, and 2019–2020 field experiments, respectively