|GURUNG, SURAJ - North Dakota State University|
|HANSEN, JANA M - North Dakota State University|
|GIRONELLA, ANN INEZ - Idaho State University|
|ADHIKARI, TIKA - North Dakota State University|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/20/2012
Publication Date: N/A
Interpretive Summary: Leaf spot diseases of wheat can be important constraints to wheat production worldwide and breeding resistant wheat cultivars is an economical means to manage these diseases. A first step in breeding for disease resistance is to identify resistance sources. Using wheat accessions from the core subset of the National Small Grains Collection, we identified winter wheats that are resistant to multiple leaf spot diseases. These accessions should be useful to wheat breeders in their efforts to broaden the genetic base of disease resistance in US wheat cultivars.
Technical Abstract: Tan spot (Pyrenophora tritici-repentis), Stagonospora nodorum blotch (SNB) (Phaeosphaeria nodorum), spot blotch (Cochliobolus sativus) and Septoria tritici blotch (STB) (Mycosphaerella graminicola) are the most important leaf spot diseases impacting wheat production worldwide. Most commercially grown wheat cultivars are resistant to at least one of the diseases, but susceptible to the others. The main objective of this study was to identify novel sources of resistance to multiple leaf spot pathogens in a subset of winter wheat accessions from the core collection of the National Small Grains Collection (NSGC) of the USDA-ARS. In total, 633 winter wheat accessions were evaluated for multiple leaf spot diseases in a greenhouse and 205, 278, 146 and 68 accessions were resistant to tan spot, SNB, spot blotch, and STB, respectively. Among the 633 accessions tested, 56 accessions have resistance to at least three of the diseases and five accessions (CItr 16595, PI 278612, PI 351330, PI 361858, and PI 351983) were resistant to all four diseases tested. Based on Germplasm Resources Information Network (GRIN) data, 17 of the 56 wheat accessions were resistant to at least two additional key diseases. These results suggest that resistant winter wheat accessions identified in this study have broad-spectrum resistance to leaf diseases and can be used in wheat breeding programs.