|SINGH, PAWAN - International Maize & Wheat Improvement Center (CIMMYT)|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/1/2009
Publication Date: 8/1/2009
Citation: Gurung, S., Bonman, J.M., Ali, S., Patel, J., Myrfield, M., Mergoum, M., Singh, P.K., Adhikari, T.B. 2009. New and Diverse Sources of Multiple Disease Resistance in Wheat. Crop Sci. 49:1655-1666.
Interpretive Summary: Tan spot and Stagonospora nodorum blotch are important diseases of wheat in the upper Midwest. In this work, we screened 825 wheat accessions fro the USDA-ARS National Small Grains Collection (NSGC) for resistance to the two diseases and found 88 accessions that were resistant to both diseases. We also identified that 28 of these 88 were resistant to other key wheat diseases based on previously generated NSGC data. The 88 resistant accessions were diverse based on geographic origin and on molecular marker constitution and thus are likely to have new resistance genes. These accessions will be useful to plant breeders in developing improved wheat varieties with resistance to multiple diseases.
Technical Abstract: A group of 825 common wheat accessions from the National Small Grains Collection (NSGC) wheat core subset was evaluated for resistance to tan spot [Pyrenophora tritici-repentis (Died.) Drechs.] and Stagonospora nodorum blotch (SNB) [Phaeosphaeria nodorum (E. Muller) Hedjarroude] at the seedling stage in the greenhouse. Eighty-eight wheat accessions exhibited resistance to both diseases. Data from the Germplasm Resources Information Network (GRIN) were examined for the 88 accessions to identify those that also had resistance to other key diseases and on this basis 28 accessions with multiple resistances were identified. The genetic relationship among the 88 accessions was assessed using resistance gene analog polymorphism (RGAP) primers. Using genetic similarity calculated as Dice’s coefficient, wheat accessions with similar growth habit grouped together despite differences in country of origin. Associations between agronomic traits and host resistance indicated that winter wheat habit was strongly associated with both SNB and tan spot resistance. Overall, this study identified genetically diverse wheat accessions with resistance to multiple diseases that can be utilized in wheat breeding.