Fruit Nutritional Composition and Seed Reserve Mobilization as Tools for Phenotypic Selection in Eugenia patrisii (Myrtaceae)

Understanding the integration of metabolic fluxes in fruits and seeds is crucial for identifying key biochemical markers for phenotypic selection in tropical species. This study investigated the Amazonian fruit species <i>Eugenia patrisii</i> (Myrtaceae), known for its nutritional and biotechnological potential, to elucidate the link between fruit chemistry and primary reserve mobilization during germination and early seedling growth. Botanical material was collected from an experimental plantation in Maraba, Pará, Brazil. Three contrasting phenotypes (Ph2, Ph3, and Ph6) were analyzed for fruit proximate composition as well as the dynamics of carbohydrates and protein use over seven germination stages. Fruits predominantly contained carbohydrates (76.6-79.3 g/100 g) and proteins (12.7-17.5 g/100 g) and had low lipid content (<5 g/100 g), indicating high energy conversion efficiency. Phenotype Ph6 showed higher protein accumulation and intensive reserve metabolism in late development stages, while Ph2 featured greater soluble sugar content, indicating contrasting reserve allocation strategies. Principal component analysis (PCA) and the indices of integrated metabolic flux (MFI) and total activity (TAI) revealed distinct metabolic cost patterns and biochemical efficiency among phenotypes. Together, these results demonstrate that fruit nutritional attributes and seed metabolic behavior provide quantitative criteria for identifying superior phenotypes, with Ph3 and Ph6 emerging as promising candidates for domestication, breeding, and conservation programs.