An interspecific barberry hybrid enables genetic dissection of non-host resistance to the stem rust pathogen Puccinia graminis.

Academic Article

Abstract

  • Stem rust, caused by Puccinia graminis (Pg), remains a devastating disease of wheat, and the emergence of new Pg races virulent on deployed resistance genes fuels the ongoing search for sources of durable resistance. Despite its intrinsic durability, non-host resistance (NHR) is largely unexplored as a protection strategy against Pg, partly due to the inherent challenge of developing a genetically tractable system within which NHR segregates. Here, we demonstrate that Pg's far less studied ancestral host, barberry (Berberis spp.), provides such a unique pathosystem. Characterization of a natural population of B. ×ottawensis, an interspecific hybrid of Pg-susceptible B. vulgaris and Pg-resistant B. thunbergii (Bt), reveals that this uncommon nothospecies can be used to dissect the genetic mechanism(s) of Pg-NHR exhibited by Bt. Artificial inoculation of a natural population of B. ×ottawensis accessions, verified via genotyping by sequencing to be first-generation hybrids, revealed 51% susceptible, 33% resistant, and 16% intermediate phenotypes. Characterization of a B. ×ottawensis full sib family excluded the possibility of maternal inheritance of the resistance. By demonstrating segregation of Pg-NHR in a hybrid population, this study challenges the assumed irrelevance of Bt to Pg epidemiology and lays a novel foundation for the genetic dissection of NHR to one of agriculture's most studied pathogens.
  • Authors

  • Bartaula, Radhika
  • Melo, Arthur TO
  • Connolly, Bryan A
  • Jin, Yue
  • Hale, Iago
  • Status

    Publication Date

  • April 27, 2018
  • Has Subject Area

    Published In

    Keywords

  • Barberry
  • genotyping by sequencing
  • non-host resistance
  • stem rust
  • wheat
  • Digital Object Identifier (doi)

    Start Page

  • 2483
  • End Page

  • 2493
  • Volume

  • 69
  • Issue

  • 10