The Effect of Rice Plant Components on Rice Plant Pathogen. I

Abstract
The Fusarium leaf spot disease was caused by Gerlachia oryzae. Infection of this pathogen is initiated by the conidial anastomosis to form a conidial complex on rice plant and then hyphae grown from the conidial complex invaded the plant tissue through stomata and injured parts. The promoting substances for the conidial anastomosis in the first stage of infection may be involved in the rice plant. We tried to search the promoting substances for the conidial anastomosis of G. oryzae and 8 sugar lactones (1-8) were isolated from the rice plant extract. Their activities for the conidial anastomosis were tested.