A multienvironmental evaluation of the N, P and K use efficiency of a large wheat diversity panel

Although the genotypic variation of nutrient use efficiency of bread wheat has been a focus of many previous studies, this variation may largely depend on the growth environment and the range of wheat cultivars being investigated. The present study aimed to examine the influence of the growth environment on the genotypic variation of nutrient use efficiency of wheat, the relationship between nutrient use efficiency parameters and yield or grain quality, and the changes in nutrient use efficiency parameters with wheat breeding history. We conducted a two-year field experiment at four different sites, and the genotypic variation of 12 nitrogen (N), phosphorus (P) and potassium (K) use efficiency parameters (NUE, PUE and KUE) were investigated in a large wheat diversity panel composed of 437 wheat cultivars released over more than 150 years. Compared with previous reports, our study expanded the lower limits of the ranges of nutrient use efficiency parameters. The NUE parameters were strongly positively correlated with the corresponding PUE parameters. Yield showed significant positive genetic correlations with most nutrient use efficiency parameters and was more strongly correlated with nutrient uptake efficiency. There was no significant genetic correlation between NUE, PUE or KUE with grain N concentration. Compared to tall cultivars, semi-dwarf wheat cultivars had higher P, K harvest index, N, K grain production efficiency. N harvest index, N, P uptake efficiency of the semi-dwarf cultivars slowly increased along with breeding history, and the relationships with breeding history for other parameters are largely environmental dependent. In conclusion, the greater genotypic variation of nutrient use efficiency of wheat revealed in our study provides insights into the improvement of nutrient-efficient wheat cultivar breeding. NUE and PUE could be improved simultaneously through wheat breeding. The nutrient harvest index, nutrient uptake and grain production efficiency could be target traits for nutrient-efficient wheat cultivar breeding.