Page 300 - PC2019 Program & Proceedings

PLANT CANADA 2019

P173. Reactions of Eastern Canada oat genotypes to crown rust
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Xue, A. ; J. Menzies ; Y. Chen ; W. Yan ; B. Ma ; W. Guo ; F. Gao ; J. Liu ; C. Ren
1 AAFC
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Agriculture and Agri-Food Canada
3 Heilongjiang Bayi Agricultural University
4 Inner Mongolia Agricultural University
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Baicheng Academy of Agricultural Sciences
Crown rust, caused by Puccinia coronate f. sp. avenae (Pca), is the most important disease and yield
limiting factor of oat production in Eastern Canada. In this study 101 oat genotypes composed of 51
cultivars and 50 breeding lines from eight oat breeding programs across Canada were evaluated for
seedling reactions to six common Pca races and a bulk inoculum of Pca in greenhouse trials and for adult
plant resistance (APR) to natural populations of Pca in field trials in 2014 and 2015. Sixty six genotypes
showed resistant reactions to at least one of the six races; of which, 22 were resistant to all six races.
These 22 genotypes also showed resistance to the bulk inoculum at the seeding stage and to the natural
populations of Pca at the adult plant stage, suggesting that these current and future oat varieties have
effective resistance against the common races and Pca populations in the region. Eleven genotypes,
including 12ANS03, AAC Bullet, CFA1213, CFA1306, Idaho, OA1301-1w-3, OA1369-5, OA1370-2,
OA1371-2, OA1383-2, and Oscar, were susceptible as seedlings but resistant as adult plants. APR is
proven to be long lasting and provide broad-spectrum resistance to Pca populations and the 11 oat
genotypes identified with APR in the present study are more desirable as sources of resistance for
breeding programs aiming to develop durable crown rust resistant cultivars for Eastern Canada.

Allen Xue (allen.xue@canada.ca)

P174. Diversity in virulence frequencies and race structure of extensively and intensively sampled
populations of Puccinia coronata Corda var avenae f.sp. avenae.
Menzies, J. ; J. Zhao ; S. Deceuninck ; H. Derksen ; Z. Popovic
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1 Agriculture and Agri-Food Canada
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Morden Research and Development Centre

Virulence frequencies and race structure of populations of Puccinia coronata Corda var avenae f.sp.
avenae (Pca) in Manitoba and Eastern Saskatchewan are monitored annually. Samples are collected each
year using an extensive sampling procedure which involves collecting one Pca isolate per field from
many fields. Another approach would be to use an intensive sampling procedure involving collecting
many Pca isolates per field from a few fields. The objective of this study was to compare the virulence
frequencies and race structure of two Pca populations; one collected using an extensive sampling
procedure and the second collected using an intensive sampling procedure. A single pustule isolate (spi)
was collected from each of 13 fields of cultivated oat, and 69 fields infested with wild oat for the
extensive sampling procedure, and 49 spi were collected from two fields of cultivated oat and 59 spi from
two fields infested with wild oat for the intensive sampling procedure in the target areas in 2018. The
individual spi were used to determine virulence frequencies and races on 24 differential lines. Virulence
frequencies were similar among the two collections, but the race structure was more diverse in the
extensive sampling population compared to the intensive sampling population.

Jim Menzies (jim.menzies@canada.ca)

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