Spring Wheat Genes Show Strong Resistance to Yellow Rust in Field Conditions

Jenn Hoskins
18th June, 2024

Spring Wheat Genes Show Strong Resistance to Yellow Rust in Field Conditions

Image Source: Natural Science News, 2024

Key Findings

  • The study tested the effectiveness of three APR genes—Yr18, Yr29, and Yr46—against yellow rust in wheat fields in Denmark and the UK
  • All three APR genes significantly reduced disease severity, with Yr18 and Yr46 being particularly effective
  • Advanced techniques, including deep learning, were used to quantify fungal biomass, providing precise and objective measures of disease resistance
Yellow rust, caused by the fungus Puccinia striiformis f. sp. tritici (Pst), is a significant threat to wheat production globally. The disease can lead to severe yield losses, making it a critical concern for farmers and researchers. Traditional resistance strategies have relied on major race-specific genes, but these often lose effectiveness as the pathogen evolves. Recently, attention has shifted to adult plant resistance (APR) genes, which tend to offer more durable protection. A new study by the Crop Research Institute focuses on the effectiveness of three APR genes—Yr18, Yr29, and Yr46—against current Pst races in North-West Europe[1]. The study involved sibling wheat lines developed at CIMMYT, where each pair consisted of one line with a functional APR gene and another with its non-functional allele. These lines were tested against three significant Pst races: Warrior, Warrior (–), and the highly aggressive PstS2. The research was conducted in field conditions in Denmark and the United Kingdom, regions known for their varying disease pressures. The results showed that all three APR genes had a significant effect in reducing disease severity, with Yr18 and Yr46 particularly effective in slowing disease progression. In Denmark, susceptible control plants reached 100% disease severity, highlighting the aggressive nature of the pathogen in this region. In contrast, the United Kingdom experienced lower disease pressure, yet the APR genes still demonstrated substantial protective effects. These findings suggest that incorporating these APR genes into wheat breeding programs could enhance resistance to yellow rust in North-West Europe. To validate the field results, the researchers employed advanced techniques to quantify fungal biomass in leaf samples. Microscopic image analyses using deep learning were used to assess the early stages of disease development. This method allowed for a detailed evaluation of how the APR genes affected both leaf colonization and pustule formation. The deep learning approach provided a precise and objective measure of fungal growth, offering a significant improvement over traditional, more subjective methods of disease assessment[2]. The study’s findings are particularly relevant in the context of previous research. For instance, earlier studies have shown that yellow rust epidemics are often driven by a few highly divergent genetic lineages of Pst, with different lineages predominating in various regions[3]. The high genetic diversity and frequent recombination observed in South Asia, for example, make it difficult to predict the emergence of new, highly virulent races. This unpredictability underscores the importance of continuous investment in pathogen surveillance and the development of resistant crop varieties. Moreover, the economic impact of yellow rust is substantial. It is estimated that 5.47 million tonnes of wheat are lost to the pathogen annually, translating to a financial loss of approximately US$979 million each year. Given these figures, sustained research investment in developing resistant wheat varieties is not only scientifically but also economically justified[4]. The study by the Crop Research Institute aligns with this perspective, demonstrating that APR genes can be a valuable tool in mitigating the impact of yellow rust. In summary, the research conducted by the Crop Research Institute provides compelling evidence that APR genes Yr18, Yr29, and Yr46 offer significant protection against yellow rust in North-West European wheat fields. The use of deep learning for quantifying fungal biomass represents an innovative approach to assessing disease resistance, offering a more accurate and reliable method compared to traditional techniques. These findings contribute to a broader understanding of how to effectively combat yellow rust and highlight the importance of ongoing research and investment in crop protection strategies.

AgricultureGeneticsPlant Science


Main Study

1) The adult plant resistance (APR) genes Yr18, Yr29 and Yr46 in spring wheat showed significant effect against important yellow rust races under North-West European field conditions

Published 17th June, 2024


Related Studies

2) A simple method for comparing fungal biomass in infected plant tissues.


3) Yellow Rust Epidemics Worldwide Were Caused by Pathogen Races from Divergent Genetic Lineages.


4) Research investment implications of shifts in the global geography of wheat stripe rust.


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