Genetic Variability, Broad-Sense Heritability, and Selection of Superior Genotypes for Fruit Improvement in Platonia insignis

Platonia insignis Mart. is a native Amazonian fruit tree with considerable agro-industrial potential, yet it remains underutilized due to limited domestication efforts and the absence of breeding programs or improved genetic lines. This study aimed to estimate genetic parameters based on morpho-agronomic fruit traits and to identify superior genotypes from natural coastal populations in the Brazilian Amazon. Thirteen genotypes were evaluated for 16 biometric and compositional traits. Genetic parameters were estimated using REML/BLUP (Restricted Maximum Likelihood/Best Linear Unbiased Prediction) procedures, and a rank–sum selection index was applied to identify elite individuals. The results revealed substantial phenotypic and genetic variability, with broad-sense heritability values ranging from moderate to high for key traits, including longitudinal fruit diameter (0.81), fruit fresh mass (0.66), and seed fresh mass (0.75). Selection accuracy was high (≥0.96) across most traits, indicating strong experimental reliability. Genotypic correlations highlighted favorable associations among traits related to pulp yield, sugar content, and seed reduction. Six superior genotypes (G7, G1, G6, G3, G2, and G4) exhibited optimal profiles for fruit quality and productivity. These findings provide a strong foundation for breeding strategies and support the genetic conservation and domestication of P. insignis as a native species of high economic and ecological importance.