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United States Department of Agriculture

Agricultural Research Service

Title: Evaluation of seedling resistance to tan spot and Stagonospora nodorum blotch in tetraploid wheat

Authors
item Chu, C. - NORTH DAKOTA STATE UNIV.
item Friesen, Timothy
item Faris, Justin
item Xu, Steven

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 17, 2007
Publication Date: June 2, 2008
Citation: Chu, C.G., Friesen, T.L., Faris, J.D., Xu, S.S. 2008. Evaluation of seedling resistance to tan spot and Stagonospora nodorum blotch in tetraploid wheat. Crop Science. 48:1107-1116

Interpretive Summary: Tetraploid durum wheat is an important cereal crop specifically used for making pasta products. Durum is more vulnerable to various wheat diseases than bread wheat. In order to identify resistant sources useful for improving durum resistance to two destructive foliar diseases, tan spot and Stagonospora nodorum blotch (SNB), a total of 688 accessions belonging to five durum wheat relatives including Persian wheat, cultivated emmer wheat, Polish wheat, Oriental wheat, and Poulard wheat, were evaluated as seedlings for resistance to tan spot and SNB. The data showed that 25 and 132 accessions were resistant to tan spot and SNB, respectively, with 10 of the accessions including cultivated emmer and Poulard wheat having resistance to both diseases. The resistant accessions identified in this study will be particularly useful for developing durum wheat germplasm with resistance to tan spot and SNB because of their close relationship with durum wheat.

Technical Abstract: Tetraploid durum wheat (Triticum turgidum L. ssp. durum, 2n = 4x = 28, AABB) is an important cereal specifically used for making pasta products but its production is more vulnerable to various wheat diseases than hexaploid bread wheat (T. aestivum L., 2n = 6x = 42, AABBDD). In order to identify resistant sources useful for improving durum resistance to two destructive foliar diseases, tan spot [caused by Pyrenophora tritici-repentis (Died.) Drechs.] and Stagonospora nodorum blotch (SNB) [caused by Phaeosphaeria nodorum (E. Muller) Hedjaroude; anamorph: Stagonospora nodorum (Berk.) Castellani & E. G. Germano], a total of 688 accessions belonging to the tetraploid wheat (T. turgidum L. ssp, 2n = 4x = 28, AABB) subspecies carthlicum, polonicum, turgidum, dicoccum and turanicum were evaluated for their seedling resistance to P. tritici-repentis and P. nodorum. Accessions were inoculated with a P. tritici-repentis race 1 isolate (Pti2) and a mixture of three diverse isolates of P. nodorum (Sn4, Sn5 and Sn2000), respectively. Then 206 accessions with low and intermediate disease reaction to either of inoculum were further evaluated for reactions to P. tritici-repentis and P. nodorum as well as sensitivity to host-selective toxins produced by the two pathogens. Evaluation data showed that 25 and 132 accessions were resistant to tan spot and SNB, respectively, with 10 accessions including T. dicoccum and T. turgidum showing resistance to both diseases. The resistant accessions identified in this study would be particularly useful for developing durum wheat germplasm resistant to tan spot and SNB due to their semi-domesticated characteristics and same genomic constitutions as durum wheat.

Last Modified: 9/20/2014
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