|YIMER, BELAYNEH - Orise Fellow|
|HARRISON, STEPHEN - Louisiana State University|
|Esvelt Klos, Kathy|
Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/25/2018
Publication Date: 5/30/2018
Citation: Yimer, B., Gordon, T.C., Harrison, S., Kianian, S., Bockelman, H.E., Bonman, J.M., Esvelt Klos, K.L. 2018. New sources of adult plant and seedling resistance to Puccinia coronata f. sp. avenae identified among Avena sativa accessions of the national small grains collection. Plant Disease. https://doi.org/10.1094/PDIS-04-18-0566-RE.
Interpretive Summary: The resistant oat accessions identified in this study are useful in facilitating oat breeding for crown rust resistance. The resistant accessions may be included in breeding programs to evaluate their agronomic performances; or the accessions can be further characterized to identify and locate the genes that are responsible for resistance. These accessions will play an important role in widening the genetic base of crown rust resistance in oats. The accessions may also serve as the best alternatives to transfer crown rust resistance genes to locally adapted oat cultivars. Overall, these accessions may have a paramount importance in developing oat cultivars with durable crown rust resistance.
Technical Abstract: Accessions of cultivated oat (A. sativa L.) from the USDA-ARS Small Grains Collection in Aberdeen, ID were characterized for adult plant resistance (APR) and seedling resistance to crown rust, caused by Puccinia coronata f. sp. avenae (Pca). Initially, 607 oat accessions with diverse geographic origins were evaluated in field tests in Baton Rouge, LA. Of those, 97 accessions were not fully susceptible and were tested in the field in St. Paul, MN against a diverse Pca population. Thirty-six accessions that had some level of resistance in both field tests, and mean coefficient of infection of =20 were further evaluated for APR and seedling resistance. Among these, four accessions, PI 193040, PI 194201, PI 237090 and PI 247930, were resistant to eight Pca races as seedlings. Twenty-nine accessions had resistance to at least one of the Pca races. Three accessions, CIav 2272, CIav 3390 and PI 285583, were fully susceptible to all eight Pca races as seedlings. Further evaluation of the three seedling-susceptible accessions at the flag leaf stage in a growth chamber resulted in moderately susceptible to moderately resistant responses. The resistance sources presented here may contain genes not deployed in elite oat varieties, and may be useful for future crown rust resistance breeding. The adult and seedling resistance found in accessions of the cultivated oat species is especially valuable as it avoids problems associated with the transfer of genes from wild species to cultivated oat.