Triticeae Genomics and Genetics, 2025, Vol.16, No.4, 184-194 http://cropscipublisher.com/index.php/tgg 185 2 Major Wheat Diseases and Resistance Genes 2.1 Overview of key wheat diseases Wheat is susceptible to a variety of diseases that affect yield and quality. The more common ones are leaf rust (Puccinia triticina), stripe rust (Puccinia striiformis) and stem rust (Puccinia graminis). These diseases occur in many countries and are prone to outbreaks (Ghimire et al., 2020; Ren et al., 2024). Powdery mildew is another common disease caused by Blumeria graminearum. This disease has always existed in many growing areas and is difficult to completely eliminate (Zou et al., 2018; Cai and Qian, 2024). Fusarium head blight (FHB) is also a serious disease caused by Fusarium graminearum. Not only will it reduce yields, but it may also cause food to be contaminated by mycotoxins, affecting food safety (Figure 1) (Ghimire et al., 2020). These diseases cause a lot of losses every year, so they are the focus of wheat breeding in various places (Mourad et al., 2024). Figure 1 Fusarium head blight (FHB) symptom; FHB disease in the field used to assess FHB incidence (type I resistance) (A), infected spike with orange-colored sporodochia used to assess FHB severity (type II resistance) (B), infected seed used to assess Fusarium-damaged kernel (FDK) (type IV resistance) (C) compared to healthy seed lot (D), F. graminearumoverwintering in corn stalk (E), and FHB isolate cultured in potato dextrose agar (PDA) plate showing characteristic pinkish-red colony (F). (Source: Figures 1A-F, B. Ghimire) (Adopted from Ghimire et al., 2020) 2.2 Resistance genes identified in wheat germplasm Researchers have discovered many disease resistance genes in wheat and used them for breeding. There are many confirmed rust resistance genes, including 79 leaf rust resistance genes (Lr), 82 stripe rust resistance genes (Yr) and multiple stem rust resistance genes (Sr). Some of the common ones are Lr13, Lr67, Yr27, Sr26, Sr61 and Sr43 (Milne et al., 2018; Zhang et al., 2021; Athiyannan et al., 2022; Yu et al., 2023). For powdery mildew, genes such as Pm21 and Pm60 have been cloned and verified to have good resistance (Zou et al., 2018). Fhb1 is the most
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