Abstract
Fusarium ‘F959’, a pathogenic sensitive strain to taro, was inoculated on ‘Celebes’. The inoculated corms were kept in the dark at 25°C for 15 days. Paraffin sections were made from the inoculated corms and observed cytologically under a light microscope. In control specimens, about 1 mm transparent cell layers and meristematic cell layers (normal periderm) were formed under the wound surface. The cells of all transparent layers were significantly lignified. When Fusarium was inoculated to the wound, the transparent cell layers expanded to 2-5 mm and were not lignified. It was considered that periderm formation was not normally performed by Fusarium.
Further, it was investigated whether delaying the time of inoculation after wounding would influence the response of corm to the pathogen. When the interval between wounding and inoculation was 12 hours or more, there was no expansion of transparent cell layers observed. It was considered that normal periderm formation was facilitated by some kind of defense responses occurring in the tissue of the taro.
