Sapucaia nut: Morphophysiology, minerals content, methodological validation in image analysis, phenotypic and molecular diversity in Lecythis pisonis Cambess

[Display omitted] •Sapucaia shows high phenotypic diversity with regard to macronutrients’ amounts.•Depending on the matrix, consuming ¼ of the nuts daily gets the ideal amount of Se.•The largest sapucaia seeds have one of the lowest amounts of lignin in the tegument.•X-ray technology enables efficient and non-destructive determination of seed density.•The proposed methodology can be adapted to other seeds. Sapucaia or Lecythis pisonis Cambess. is an ornamental tree that produces edible, tasty, and nutritious nuts, and can be used for timber production. Sapucaia has potential as a functional food, owing to optimal nutritional and particularly Se levels. The present study sought to characterize the seeds of 21 sapucaia matrices from forest remnants of a neotropical hotspot (Atlantic Forest) and farms in two Brazilian states. Biometrics, germination, vigor, lignin content in the teguments, minerals content, and phenotypic and molecular diversity were analyzed. The seeds of matrices 16 and 21 were the most vigorous. Nuts from matrices 21 and 17 contained the highest amounts of Se. Matrices 5, 8, and 21 were the most phenotypically distant; whereas matrix 21 was the most genetically distant. Importantly, we validated a new non-destructive and efficient X-ray-based methodology for internal and densitometric analysis of sapucaia seeds, and demonstrated a high genetic divergence among matrices.