Abstract
Using the second leaf segments excised from etiolated rice seedlings, a new method was established to research the regulatory mechanism of lamina inclination. The segments were fixed in a glass plate with a binding agent, Aron alpha 202. Exchanging the treatment solutions in the petri dish alternately, it had a great success to control the inclination rate. By this method, the constant rate of inclination is able to continue for 10 hours by added IAA, and the rates of 5 degrees per hour at 5×10<l;-5> M of IAA and 2.5 degrees per hour at buffer solution alone were obtained. From the anatomical observation, the adaxial cell of the lamina joint is assumed to be elongated at the rate of 4μ per hour by IAA. In another method with agar plate, it is asertained that an effect of IAA is obvious within 10 minutes after treatment and the effect is the most powerful as the segments were pretreated in distilled water for 24 hours after excision.
