Study of the Adult-Plant Resistance at Different Growth Stages to Stripe Rust in Wheat

Components of resistance were investigated for five adult-plant resistant (APR) wheat (Triticum aestivum) cultivars at sixgrowth stages and two temperatures in the greenhouse, and disease progress in a field trial. Chinese cultivar Chuanyu 12displayed high to intermediate infection type (IT) in the greenhouse but was highly resistant in the field. Weebill showedan intermediate IT in the greenhouse and also in the field. Chpaio, Tukuru and Saar, known to carry combinations of Yr18and 2-3 additional minor genes, were highly resistant in both experiments. Greenhouse experiments indicated that thelower IT of APR cultivars initiated at tillering stage. Latent periods (LP) for APR cultivars were generally longer as thegrowth stage progressed. We conclude that APR to stripe rust can be best characterized in field trials although significantcorrelations are seen between field severity and IT and LP measured in the greenhouse.