SEM Analysis of Mature Fruit Shells

Shells of ETH3 and control were collected at the fruit mature stage of ‘Huashuo’. The samples were fixed in 2.5% (v/v) glutaraldehyde solution for 3 h, and then post-fixed in 1.0% (w/v) osmium tetroxide for 2 h. They were washed in 0.1 mol^-1 sodium phosphate buffer. Dehydration was completed in a graded series of ethanol. Anhydrous ethanol was replaced with 3-methylbutyl acetate for SEM. The samples were critical-point dried and sputter-coated with gold, and the fracture plane of different samples was observed using SEM (Zeiss Supra 10 vp; Carl Zeiss Microscope, NY, USA) at 50-fold magnification (20 kV).