The Evolving Battle Between Yellow Rust and Wheat: Implications for Global Food Security

Abstract

Wheat (Triticum aestivum L.) is a global commodity, and its production is a key component underpinning worldwide food security. Yellow rust, also known as stripe rust, is a wheat disease caused by the fungus Puccinia striiformis f. sp. tritici (Pst), and results in yield losses in most wheat growing areas. Recently, the rapid global spread of genetically diverse sexually derived Pst races, which have now largely replaced the previous clonally propagated slowly evolving endemic populations, has resulted in further challenges for the protection of global wheat yields. However, advances in the application of genomics approaches, in both the host and pathogen, combined with classical genetic approaches, pathogen and disease monitoring, provide resources to help increase the rate of genetic gain for yellow rust resistance via wheat breeding while reducing the carbon footprint of the crop. Here we review key elements in the evolving battle between the pathogen and host, with a focus on solutions to help protect future wheat production from this globally important disease.

Longer epidermal cells underlie a quantitative source of variation in wheat flag leaf size

“…While wheat genetic studies commonly focus on the flag leaf, it is the flag, second and third leaves that growers take care to keep clean from fungal infection via chemical control (Bouvet et al ., 2021), and therefore are critical in building final grain yield. Analysis of our FLL5A NIL pair showed this locus typically increases length in the 2–3 topmost leaves, while the total leaf number per tiller and leaf emergence rate remains unchanged.…”

Genetic resistance to yellow rust infection of the wheat ear is controlled by genes controlling foliar resistance and flowering time

“…The fungal pathogen Puccinia striiformis Westend f. sp. tritici ( Pst ) causes yellow rust (YR), also known as stripe rust, in wheat ( Triticum aestivum L.) (reviewed by Bouvet et al., 2021a). The visible symptoms of YR infection, such as sporulation, are typically observed on wheat leaves.…”

“…However, under the right conditions Pst urediniospores (thin‐walled spores produced during the asexual stage of the Pst lifecycle) will also colonize leaf sheaths as well as structures of the wheat ear including the outermost structures that surround each floret (the glumes) (Figure 1a,b). Although the main concern for wheat growers is foliar infection, glume infection can become a significant problem during moderate to severe epidemics (Bouvet et al., 2021a). The Pst urediniospores infect floret tissues from heading date (Zadoks Growth Stage 55, GS55; Zadoks et al., 1974) until flowering (GS61), with symptoms appearing 10–20 d later (Wellings, 2003).…”

Identification of carriers of Puccinia striiformis resistance genes in the population of recombinant inbred wheat lines

“…Triticum aestivum L food crop at the global level, and its production is the basis of food security throughout the world [1]. World wheat production currently reaches 777.8 million tons, and world consumption per capita is 67.6 kg/year [2].…”