THE AMBIGUOUS ROLE OF 2, 4-D IN YOUNGER LEAF CULTURE OF MAIZE

In this paper we present, in tissue culture of the second foliage leaf of maize: 1. The cells close to leaf base are more sensitive to 2,4-D, and the cells far away from leaf base are less sensitive; 2. In the range of 0.02—6mg/L, 2,4-D stimulates cell division, but with concentrations of 20—40mg/L 2, 4-D inhibits it;3. Leaf cells over 21mm from leaf base lose the ability to respond to different concentrations of 2,4-D; 4. The calli induced by 2,4-D are developed predominantly from the suppressed root-primordia.