Figure 2
From: Morphology and ploidy level determination of Pteris vittata callus during induction and regeneration
Transmission electron microscopy of two cell types observed in Pteris vittata callus maintained on semi-solid callus induction medium. A) The first cell type had a characteristically large vacuole with electron-dense vacuolar tannins and a thin layer of peripheral cytoplasm. B) The second cell type had a multitude of small vacuoles, nuclei with nucleoli, endoplasmic reticulum associated with starch granules, and Golgi apparati. C) Smaller cells of the second cell type contained more plasmodesmata, and dense cytoplasm with large amyloplasts and protein-filled vacuoles. D) Heterochromatin and two nucleoli were observed in all nuclei of the second cell type. E) Invaginations in the cell wall containing vesicles. F) Plastid surrounded by Golgi apparati and vesicles near the cell wall. Endoplasmic reticulum (ER), Golgi apparatus (GA), heterochromatin (H), nuclear envelope (NE), nucleoli (Ni), protein bodies (PM), plasmodesmata (Pd), starch granules (SM), vacuole (Va), vesicles (Vs).