Races CYR34 and Suwon11-1 of Puccinia striiformis f. sp. tritici Played an Important Role in Causing the Stripe Rust Epidemic in Winter Wheat in Yili, Xinjiang, China

Abstract

Wheat stripe rust caused by Puccinia striiformis f. sp. tritici is a destructive disease. Its pathogen frequently adapts to newly invaded regions and overcomes resistance in wheat cultivars. This disease is especially important in China due to its favorable conditions for the stripe rust epidemic and the recombination population structure of pathogens. Xinjiang is a vast epidemic region in China, but very limited research on this disease has been performed in this region. In this study, we identified 25 races from 129 isolates collected from winter wheat fields from five different regions (Nileke, Xinyuan, Gongliu, Huocheng, and Qapqal) of Yili, Xinjiang, using the Chinese set of 19 differential wheat lines. All isolates were virulent on the differentials Fulhad and Early Premium, but no isolates were virulent on Yr5. Among the 25 races, Suwon11-1 was the most prevalent, followed by CYR34. Both races were found in four out of the five locations. It is important to continue monitoring stripe rust and its pathogen races in this region, as it forms a pathway between China and Central Asia. Collaborative research is essential for controlling stripe rust in this region, other regions in China, and neighboring countries.

Comparative analysis of stripe rust resistance in seedling stage and Yr gene incidence in spring and winter wheat from Xinjiang, China

“…Overall, Xinjiang wheat exhibits the highest frequency of resistance to CYR33 among the Su 11 taxa. Previous surveys have also revealed the highest proportion of Su 11 pathogenic taxa of stripe rust ( Chen et al., 2023 ; Ma et al., 2023 ). Consequently, Xinjiang wheat possesses resistance to the currently prevalent races.…”

“…The resistance of winter wheat to predominant races was generally stronger than that of spring wheat. The number of winter wheat varieties resistant to CYR33 was significantly higher than that of other races, followed by resistance to CYR31 and CYR34, two of the most virulent Pst races ( Chen et al., 2023 ; Ma et al., 2023 ). As the planting area of winter wheat in Xinjiang has expanded, host plants for Pst are maintained through summer and winter, allowing the pathogen to complete its annual cycle.…”

“…Yr5 , Yr10 , Yr15 , Yr26 , and Yr18 genes exhibit partial resistance to stripe rust and occur infrequently in Xinjiang wheat varieties. Yr26 and Yr10 genes have been overcome by CYR34, yet recent research indicates that the predominant stripe rust population in Xinjiang belongs to the Su 11 pathogenic type ( Chen et al., 2023 ; Ma et al., 2023 ). Yr26 and Yr10 retain their efficacy in controlling stripe rust in Xinjiang.…”

“…The Yr18 gene confers non-race specific resistance to stripe rust and slows infection time and spore production, resulting in adult plant resistance (APR) ( Singh et al., 2000 ). Presently, the main race types prevalent in Ili prefecture, the largest wheat-producing region of Xinjiang, are CYR34 and Su 11-1 ( Chen et al., 2023 ). It has been shown that Yr5 and Yr15 are highly resistant to stripe rust ( Zhou et al., 2023 ), making the detection of these resistance genes essential for the prevention and control of wheat stripe rust in Xinjiang.…”

Identification of Puccinia striiformis races from the spring wheat crop in Xinjiang, China

“…The vast region of Xinjiang in northwestern China is important for stripe rust epidemics. As it is located in the potential center of diversity ( Ali et al., 2014 ; Awais et al., 2022 ), the region links other Chinese epidemic regions to Central Asia ( Chen et al., 2023 ). Also, both winter and spring wheat crops grown in this region and mild summer temperatures provide a long season of host plants and favorable environmental conditions for Pst to infect, develop, and survive.…”