Development of genomic and breeding resources to uncover virulence mechanisms in oat crown rust
M. FIGUEROA (1), S. Rottschaefer (2), M. Miller (2), V. Omidvar (2), H. Karaoglu (3), F. Li (2), D. Singh (3), N. Upadhyaya (4), R. Dill-Macky (2), P. Dodds (4), R. Park (3), S. Kianian (5) (1) University of Minnesota, U.S.A.; (2) University of Minnesota, U.S.A.; (3) Plant Breeding Institute, University of Sydney, Australia; (4) CSIRO Agriculture, Australia; (5) USDA-ARS Cereal Disease Laboratory, U.S.A.

Global oat production is severely affected by crown rust disease caused by the pathogenic fungus Puccinia coronata f. sp. avenae (Pca). Sexual and asexual populations of Pca are characterized by high levels of polymorphism which pose significant challenges for breeders as resistance genes are quickly rendered ineffective by rapid pathogen evolution. In an international collaborative effort, we are integrating numerous complementary approaches to elucidate the molecular and genetic basis of virulence in Pca. In order to develop robust strategies for evaluating oat crown rust resistance in breeding programs, we identified a core collection of highly virulent Pca isolates to be used in resistance screening trials. Evaluation of oat germplasm and wild relatives with this Pca collection is underway to detect novel sources resistance. Correlations between molecular markers and virulence phenotypes have been implemented in a pilot study using a population of more than 30 Pca isolates. Furthermore, we are generating high quality genome assemblies of Pca isolates to predict candidate effector genes utilizing machine-learning strategies. Mutagenesis approaches also are in place to functionally validate effector predictions. Given that effector proteins from the pathogen are under strong selective pressure to accumulate sequence changes that allow them to evade recognition by the host, the identification of highly variable genomic regions represents a first step towards gaining a better understanding of virulence mechanisms. Overall, this research initiative will provide a better understanding of the biology of Pca and establish platforms necessary to enable the development of molecular diagnostic tools and crop improvement.

Abstract Number: P17-522
Session Type: Poster