Puccinia graminis f. sp. tritici, the causative agent of stem rust in wheat, is a devastating disease of durum wheat. While more than 50 stem rust resistance (Sr) loci have been identified in wheat, only a few of them have remained effective against Ug99 (TTKSK race) and other durum-specific Ethiopian races
The wheat (Triticum aestivum L.) cultivar ‘Stephens’ has been grown commercially in the USA Pacific Northwest for 30 years. The durable resistance of ‘Stephens’ to stripe rust (Puccinia striiformis f. sp. tritici) was believed to be due to a combination of seedling and adult plant resistance genes.
