Abstract
The effect of high temperature stress on resistance expression was studied with oatcrown rust system by exposing oat seedlings to a high temperature after inoculation with Puccinia coronata avenae. Three oat cultivars became resistant to crown rust when incubated at 35C for 8hr at the vegetative stage of fungal development. The effect of high temperature stress disappeared by cutting of the stem prior to the heat treatment. These experimental results suggest that the effect of heat treatment on disease outbreak is through its effect on the host. The relationship of high temperature stress-induced resistance and the role of lipoxygenase isozyme in induced resistance was discussed.
