Genes for Rust Resistance in International Winter Wheat Nurseries XII through XVII
- Donald V. McVey *
Genes for resistance to stem rust (Sr) (caused by Puccinia graminis Pers.:Pers. f. sp. tritici) and leaf rust (Lr) (P. recondita Roberge ex. Desmaz f. sp. tritici) were detected in cultivars of wheat (Triticum aestivum L.) of the International Winter Wheat Performance Nursery XII through XVII. The objectives were to test for the presence and distribution of Sr and Lr genes. Entries were inoculated with 28 isolates of P. graminis f. sp. tritici and 15 isolates of P. recondita f. sp. tritici, previously characterized for avirulenceJvirulenee to 26 Sr an 14 Lr genes, respectively. Sixteen of the 26 Sr genes and six of the 14 Lr genes were postulated as present. A few cultivars possessed a gene or genes for resistance other than those studied. No Sr genes for resistance were detected in three cultivars, a single gene was detected in each of 32 cultivars, two in 32, three in 13, and four Sr genes in two cultivars. Genes for stem rust resistance Sr5, SrMcN, Srl7 Sr31, and SrlO were most commonly postulated, whereas Sr7b, Sr9d, Sr9e, Srl2, Srl3, Srl4, Srl5, Srl6, Sr25, Sr26, and Sr27 were not detected in any of the entries. No Lr genes for resistance were detected in 27 cultivars, one in each of 40, two genes each in 14, and three genes in each of two cultivars. Genes for leaf rust resistance LrlO and Lr26 were most commonly postulated, whereas Lr21, Lr2c, Lr3ka, Lr9, Lrl7, LrlS, Lrl9, and Lr30 were not detected.
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