Cell ultrastructures in rape(Brassica napus L.)leaves and their calli,andmeristemoids were studied by transmission electron microscopy in detial.Our resultsshowed that their ultrastructures had many profound changes,the main differences ofthese changes were that the rape mesophyll cell was a kind of typical parenchyma cellwith many chloroplasts and a large central vacuole around which there was a littlecytoplasm.The callus cell derived from the rape mesophyll cell resembled parenchymacell of intact plant an...