Effects of EDTA and Acidified Medium on the Dedifferentiation of Immature Pollen in a Tobacco Pollen Culture

The addition of ethylenediaminetetraacetic acid (EDTA) to themedium stimulated the dedifferentiation from immature pollengrains to embryogenic cells in the tobacco pollen culture systemdeveloped by Kyo and Harada (1986). The stimulative effect ofEDTA was mainly due to the decrease in the pH of the mediumand was very marked in the pollen at the late-bicellular stage(stage IV), which did not become embryogenic under the originalculture condition. (Received September 5, 1990; Accepted September 27, 1990)