Micro-CT images and variable effective diffusivity as tools in the analysis of Cariniana estrellensis (Raddi) Kuntze seeds hydration

Priming is a technique widely used by seed technologists to improve seed vigor and stress tolerance. The underlying principle of all priming techniques is seed imbibition, which triggers pre-germinative metabolism. The present study aims to analyze the hydration process of Cariniana estrellensis seeds using the diffusion model with variable effective diffusivity in combination with micro-CT images to identify the different imbibition stages and the temperature effect on the hydration process. Hydration curves were obtained at temperatures of 25, 35, and 45 °C. Adjustments showed Chi-squared ≤ 2.82 × 10⁻⁴ for all temperature ranges. The analysis of the effective diffusivity variations allowed us to identify the three stages of the hydration process. Although temperature has a effect on hydration kinetics, it does not affect the moisture content at which each stage occurs. The micro-CT images allowed us to identify the moisture range at which germination processes begin, which corroborates the data observed from the effective diffusivity variations. Therefore, the combination of the variable diffusivity diffusion model and the analysis of micro-CT images represents a promising tool for the development of priming techniques, as it allows for the systematic evaluation of the different hydration stages.