2.2. Seed-coat thickness and hardness
Seed-coat thickness was measured for ten seed of each species.
A Nikon SMZ 1000 stereomicroscopic Zoom Microscope (Nikon
Instruments, Tokyo, Japan)wasemployed and measured with Infinity
image capture and analysis software (Luminera Corporation,
Ottawa, Canada). Measurements were taken in the center of the
cut seed equidistant from the micropylar region and the hilar end.
Hardness ratings of 1–5 were assigned after seed samples were
soaked in deionized (DI) water for 2 days and hand sectioned with