Abstract
Ozone sensitivity in rice varieties has been evaluated by visible leaf injuries. It is uncertain that a reduction of rice yield relates to visible injuries. Therefore, Japanese and Asian rice varieties were exposed to ozone and were measured visible damage and grain yield. Among the tested varieties, Indica variety Kasalath was most tolerant to visible ozone damage, and Japonica variety Kirara 397 was most sensitive. Grain yields in both Kasalath and Kirara 397 significantly decreased by the ozone exposure, whereas many Japanese varieties were almost unaffected. Ozone sensitivity in rice evaluated by visible injuries was not coincident with that evaluated by the reduction of grain yield. Current results suggested that the mechanism of chronic ozone toxicity will be hard to explain by the mechanism of acute leaf injury development. This research was financially supported by the Global Environment Research Fund Ba-086 by the Ministry of the Environment, Japan.
