抄録
Changes in nuclear dry mass (NDM), nuclear area (NA), and nuclear structure in outer epidermal cells of white onion were determined at 15-min intervals during 45 min in distilled water. Three pretreatments of onion leaf bases were used: no exposure, exposure to ambient atmosphere for 24 hr, and exposure for 48 hr. Non-exposed epidermal cells mounted in distilled water lost NDM during the first 15 min, but NDM in cells of leaf bases exposed for 24 and 48 hr remained unchanged. With all three treatments, NA decreased significantly during 45 min; moreover, the nuclear outline underwent striking changes involving the formation of perinuclear vacuoles and pycnosis. Prior exposure of a leaf base resulted in an increase in the number of perinuclear vacuoles initially and a more rapid disappearance of these vacuoles after 30 and 45 min in distilled water.
