Berry quality and nutritional composition in seabuckthorn ( <i>Hippophae rhamnoides</i> L.): a multi-year evaluation of selectively bred genotypes

This study explores selective breeding in shaping the yield, berry size, and nutritional quality of seabuckthorn ( Hippophae rhamnoides L.), a nutrient-dense berry crop with significant value-added potential. Utilizing a diverse germplasm collection evaluated over two growing seasons, we identified superior genotypes exhibiting enhanced berry weight, higher Brix values, and improved nutritional profiles. Fifty-berry weights varied from 13.2 to 38.6 g, with genotypes exhibiting notable improvements in size and sugar content. Multivariate analyses, including principal component analysis and hierarchical clustering of metabolic data, revealed distinct year-to-year differences, underscoring the strong influence of environmental conditions on fatty acids and flavonoid composition. Specifically, 2015 showed significant increases in pulp and seed lipid content, omega-3 and omega-6 fatty acids, while saturated fatty acids remained stable. Flavonoid profiling revealed elevated levels of kaempferol and quercetin without changes in total flavonoid content. Conversely, total and individual sugars were significantly higher in 2014. Carotenoid profiling during berry development revealed dynamic changes in lutein, lycopene, and carotene accumulation. Integrating seed nutritional composition with agronomic performance across both seasons, we identified genotypes AAFC-24, AAFC-13, AAFC-5, and AAFC-2 as stable, high-performing genotypes with superior yield and nutritional traits. These findings highlight the combined effects of genetics and environment on seabuckthorn berry quality, offering valuable insights for breeding programs aimed at optimizing yield, nutritional value, and functional food applications.