Abstract
The present paper deals with some physiological observations on the normal and the akiochi (autumn-declined) rice plants affected with Cochliobolus miyabeanus.
1. At 2, 4 and 6 days after the inoculation, the diseased spots of both plants were concentrically cut off in 4, 8 and 12mm diameter by punch (see Fig. 1) and the amount of protein- and soluble- form nitrogen in each parts were measured with Micro-Kjeldahl's method, respectively. In the central part (A) of the normal rice leaves, a little increase of protein-form nitrogen was observed at an early stage of the infection, but the akiochi rice leaves were not (see Fig. 2). According to paper electrophoresis, 3 peaks of the optical density (α, β and γ) were generally observed about leaf protein at the direction of cathode (see Fig. 3). In the normal rice leaves these 3 peaks were presented even at 6 days after the infection. On the contrary, β peak was disappeared in the akiochi rice leaves at 2 to 6 days after.
2. At 6 days after the inoculation, the diseased spots of both plants were cut off in 7mm diameter and the amount of zinc in these spots was measured with the dithizone method of A. O. A. C. In both the normal and the akiochi rice leaves, diseased part was less content than healthy one and the difference between diseased and healthy ones was larger in the akiochi rice leaves than in the normal rice leaves (see Table 1). From the result, zinc in the diseased leaves seems to be transferred from diseased part to healthy one.
