Plastid Organization in Phenotypically Green Leaf Tissue of a Genetic Albino Strain of Nicotiana (Solanaceae)

Plastid organization within phenotypically green leaf tissue that forms in albino plants of a genetic albino strain of Nicotiana has been examined with the transmission electron microscope. Studies revealed the presence of plastids with and without thylakoids. When present, thylakoids were loosely and irregularly scattered in the stroma or organized either into several large spindle‐shaped grana or into a single compound granum with deeply indented margins. Plastids without thylakoids were vesiculated and resembled the typical genetic albino type. Plastid types were not segregrated into individual cells and no plastid type appeared to be typical for the mutant tissue. Orientation of grana and thylakoid membrane associations were noted as well as the presence of osmiophilic globules, starch grains and DNA‐like fibrillar areas.