Location: Hard Winter Wheat Genetics ResearchTitle: Adult plant resistance to Puccinia triticina in a geographically diverse collection of Aegilops tauschii
|KALIA, BHANA - KANSAS STATE UNIVERSITY|
|WILSON, D - KANSAS STATE UNIVERSITY|
|Bowden, Robert - Bob|
|SINGH, R - INTERNATIONAL MAIZE & WHEAT IMPROVEMENT CENTER (CIMMYT)|
|GILL, B - KANSAS STATE UNIVERSITY|
Submitted to: Genetic Resources and Crop Evolution
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/18/2016
Publication Date: 6/15/2016
Publication URL: http://handle.nal.usda.gov/10113/5454541
Citation: Kalia, B., Wilson, D.L., Bowden, R.L., Singh, R.P., Gill, B.S. 2016. Adult plant resistance to Puccinia triticina in a geographically diverse collection of Aegilops tauschii. Genetic Resources and Crop Evolution. doi:10.1007/s10722-016-0411-2.
Interpretive Summary: Leaf rust is one of the most widespread and important foliar diseases of wheat. Resistance to leaf rust can be classified as either “seedling resistance” or “adult plant resistance” (APR). APR is often durable over many years whereas seedling resistance is often defeated in just a few years by new pathogen races. This study tested 371 accessions of Aegilops tauschii, a wild progenitor of wheat, for APR to leaf rust. Forty-one lines were found to have effective APR. These lines may be good sources of APR for breeding new cultivars of wheat with more durable resistance to leaf rust.
Technical Abstract: Despite extensive genetics and breeding research, effective control of leaf rust caused by Puccinia triticina Eriks., an important foliar disease of wheat, has not been achieved. This is mainly due to the widespread use of race-specific seedling resistance genes, which are rapidly overcome by new virulent races. There is increased emphasis now on the use of race-nonspecific adult plant resistance (APR) genes for durable control of leaf rust. The objective of this study was the evaluation of Aegilops tauschii Coss. (the D-genome donor of bread wheat) for APR, previously known to be a rich source of seedling resistance genes to leaf rust. A geographically diverse collection of A. tauschii maintained by the Wheat Genetics Resource Center was evaluated for APR in the field with a leaf rust composite culture of predominant races. Out of a total of 371 A. tauschii accessions, 50 with low to moderate levels of disease severity were subsequently tested at the seedling stage in the greenhouse with four races and one composite culture of leaf rust. Nine accessions displayed moderate resistance to one or more races of leaf rust at the seedling stage. The remaining 41 seedling-susceptible accessions are potential sources of new APR genes. Accessions from Afghanistan only displayed APR whereas both seedling resistance and APR were common in the Caspian Sea region (Iran and Azerbaijan). The APR in these newly identified A. tauschii accessions will be further characterized for novelty, effectiveness, and race-specificity.