DisplayTitle

Disease resistance of wheat can vary from year to year due to the environment, causing concern to growers and breeders alike. We are studying temperature sensitive resistance responses in the interaction between hexaploid wheat and the yellow (stripe) rust pathogen <i>Puccinia striiformis</i> f. sp <i>tritici</i> (<i>Pst</i>) in controlled environment chambers. With variety UC1041 there was no significant difference in leaf pustule cover between plants kept at day temperatures of 18°C and 25°C respectively, both with a night temperature of 12°C. However when plants were shifted following infection with <i>Pst</i> from 25°C to 18°C, resistance was notably compromised with percent infection increasing up to 3 fold. In contrast, plants shifted from the 18°C to 25°C day temperatures were virtually resistant. Alpowa responds in a similar manner to UC1041 under the same temperature treatments, but Jupateco does not. We hypothesise that temperature fluctuations in the field may compromise resistance in some wheat varieties but not others. Further experiments are being performed to establish how the magnitude of the shift affects resistance and whether temperature-compromised resistance occurs in other wheat varieties on the recommended list. We are also analysing climate projections to estimate temperature fluctuations that will occur in the future. Our results will inform breeding practices and help develop wheat varieties with improved resistance performance in the future. <p><p>Keywords: Fungus, Cereals-Grains, Wheat