Exploring the Relationship between Nitrogen Use Efficiency and Protein Concentrations in Potato Genotypes

Abstract

This two-year study assessed nitrogen use efficiency (NUE) and its effect on potato tuber protein concentration, focusing on crude protein concentration (CPC), crude protein yield (CPY), and patatin relative abundance (PRA) across 19 potato genotypes and four nitrogen management treatments (organic with no added fertilizers and three integrated treatments with N rates of 60, 120, and 180 kg ha−1). Nitrogen availability significantly affected CPC, with the highest average CPC across genotypes being 10.7% at 180 kg ha−1 and the lowest of 8.15% at 60 kg ha−1. Certain genotypes consistently outperformed others in terms of CPC and/or CPY under varying nitrogen treatments. A significant negative correlation was found between CPC and NUE, and genotypes with higher NUE typically had lower CPC. A positive correlation between CPY and NUE was observed, with the highest CPY of 1.36 t ha−1 at 120 kg N ha−1 in 2020. This suggests that higher NUE genotypes are more efficient in protein production per unit area. PRA varied significantly among genotypes, ranging from 8.7% to 35.51%. Although the relationship between NUE and PRA was weak, the significant and negative correlation indicates that cultivars with high NUE could have low PRA and vice versa. The findings underscore the importance of genotype variability in the relationship between NUE and protein content in potato tubers.