Abstract
1. In the present paper, the writers described the result of investigations on the contents of starch and sugars, and also the activities of β-amylase and invertase in the different parts of diseased leaves of rice plant infected by Cochliobolus miyabeanus.
2. In the tissue surrounding the spotted area, the content of starch increased and the activity of invertase was promoted, but the decrease was found in both the content of sugars and the activity of β-amylase. On the other hand, in the healthy part of diseased leaves, only the decrease in sugar content was recognized.
3. Judging from these experimental results, it may be conceivable that the mechanism of this abnormal starch acculation is partially based on the decreased activity of β-amylase in the area surrounding the spots.
