3 years ago

Puccinia coronata f. sp. avenae: a threat to global oat production

Shahryar F. Kianian, Robert F. Park, Madeleine Smith, Feng Li, Melania Figueroa, Eric S. Nazareno
Puccinia coronata f. sp. avenae (Pca) causes crown rust disease in cultivated and wild oat (Avena spp.). The significant yield losses inflicted by this pathogen makes crown rust the most devastating disease in the oat industry. Puccinia coronata f. sp. avenae is a basidiomycete fungus with an obligate biotrophic lifestyle and is classified as a typical macrocyclic and heteroecious fungus. The asexual phase in the life cycle of Pca occurs in oat while the sexual phase occurs primarily in Rhamnus species as the alternate host. Epidemics of crown rust occur in areas with warm temperatures (20 to 25°C) and high humidity. Infection by the pathogen leads to plant lodging and shriveled grain of poor quality. Disease symptoms. Infection of susceptible oat varieties gives rise to orange-yellow round-to-oblong uredinia (pustules) containing newly formed urediniospores. Pustules vary in size and can be larger than five mm in length. Infection occurs primarily on the surfaces of leaves, although occasional symptoms develop in the oat leaf sheaths and/or floral structures like awns. Symptoms in resistant oat varieties vary from flecks to small pustules, typically accompanied by chlorotic halos and/or necrosis. The pycnial and aecial stages are mostly present in the leaves of Rhamnus species, but occasionally symptoms can also be observed in petioles, young stems, and floral structures. Aecial structures display a characteristic hypertrophy and can differ in size, occasionally reaching more than five mm in diameter. Taxonomy. Puccinia coronata f. sp. avenae (Pca) belongs to the kingdom Fungi, phylum Basidiomycota, class Pucciniomycetes, order Pucciniales, and family Pucciniaceae. Host range. P. coronata sensu lato can infect 290 species of grass hosts. Puccinia coronata f. sp. avenae is prevalent in all oat growing regions, and compared to other cereal rusts, it displays a broad telial host range. The most common grass hosts of Pca include cultivated hexaploid oat (Avena sativa) and wild relatives such as bluejoint grass, perennial ryegrass, and fescue. Alternate hosts include several species of Rhamnus, with R. cathartica (common buckthorn) as the most important alternate host in Europe and North America. Control. Most crown rust management strategies involve the use of rust-resistant crop varieties and application of fungicides. Attaining durability of resistance against Pca has been difficult for it is a highly variable pathogen with a great propensity to overcome the genetic resistance of varieties. Thus, adult plant resistance is often exploited in oat breeding programs to develop new crown rust-resistant varieties. Useful website: https://www.ars.usda.gov/midwest-area/st-paul-mn/cereal-disease-lab/docs/cereal-rusts/race-surveys/ This article is protected by copyright. All rights reserved.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1111/mpp.12608

You might also like
Never Miss Important Research

Researcher is an app designed by academics, for academics. Create a personalised feed in two minutes.
Choose from over 15,000 academics journals covering ten research areas then let Researcher deliver you papers tailored to your interests each day.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.