Integrating Canopy Dynamics and Grain Nutritional Profiles Reveals Genotypic Variation in Rye (Secale cereale L.)

Rye (Secale cereale L.) is a resilient cereal of growing importance for sustainable agriculture; however, integrative studies combining field-based canopy monitoring with detailed grain nutritional characterization remain limited. This study characterized four rye genotypes (Generator, Bar Power, L-INIA, and Lunator) by integrating unmanned aerial vehicle (UAV)-derived normalized difference vegetation index (NDVI) measurements with agronomic and grain nutritional assessments. Canopy development was monitored on three sampling dates during the growing season under two sowing dates, while plant architecture, grain nitrogen and protein concentrations, amino acid composition, and vitamin profiles were characterized at the genotype level. Significant genotypic differences were observed across multiple traits. Generator consistently exhibited high NDVI values and showed the highest grain nitrogen (2.74%) and estimated crude protein (approximately 15.96%) concentrations. L-INIA exhibited the greatest plant height (43.4 cm), largest leaf area (31.0 cm2), and highest total water-soluble vitamin concentration (223 mg 100 g−1 DW), whereas Bar Power accumulated the highest total fat-soluble vitamin concentration (81 µg g−1 DW). Lunator generally displayed intermediate values across the evaluated traits. Although total amino acid pools did not differ significantly among genotypes, individual amino acids showed distinct genotype-specific patterns. Collectively, these results demonstrate that temporal canopy development and grain nutritional composition capture complementary dimensions of genotypic variation in rye. Exploratory correlations between temporal NDVI descriptors and grain nutritional traits revealed no statistically significant associations after correction for multiple comparisons, indicating that canopy dynamics did not provide a validated predictor of grain nutritional composition in the evaluated genotypes. Under the environmental and management conditions evaluated, integrating temporal UAV-based canopy monitoring with nutritional profiling provided a comprehensive approach for characterizing genotype-specific agronomic and nutritional attributes relevant to rye improvement.