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Genetics

Inheritance of Virulence of Puccinia recondita f. sp. tritici on Durum and Spring Wheat Cultivars. Glen D. Statler, Professor, Department of Plant Pathology, North Dakota State University, Fargo 58105; Phytopathology 72:210-213. Accepted for publication 21 May 1981. Copyright 1982 The American Phytopathological Society. DOI: 10.1094/Phyto-72-210.

Cultures 70-1 and 71-112 Puccinia recondita f. sp. tritici were crossed and the resulting F₁ selfed to study the inheritance of virulence on several isogenic lines of Triticum aestivum and cultivars of T. durum. Segregation of F₂ cultures on isogenic lines with genes Lr1, Lr2, Lr3ka, Lr11, Lr17, LrEG, and LrT fit a model in which single recessive genes conditioned virulence. Segregation on the durum cultivars Botno, Calvin, Edmore, Rugby, Ward, and Vic also fit a single recessive gene model. Segregation on Wells was closer to a 9:7 than a 3:1 ratio. Most of the single recessive genes for virulence were inherited independently except for a rather close linkage between p11 and pEG and linkage between p1 and pEG. Several associations were detected between genes for virulence on the durum cultivars. Genes for virulence on Edmore were apparently linked to those for virulence on Lr11, LrEG, Botno, and Calvin. Genes for virulence on Rugby were linked to those for virulence on LrT, Botno, and Edmore. Genes for virulence on Ward were linked to those for virulence on Botno, Edmore, and Rugby. Linkage was also indicated between genes for virulence on Botno and those for virulence on Calvin, Edmore, Rugby, and Ward. The F₂ segregations that fit 3:1 ratios on the durums also fit a 1:2:1 ratio when the infection types 2 and 2+ were placed in the intermediate category. Segregation for virulence on lines with Lr10, Lr16, and cultivars 5534, Waldron, and Olaf fit a digenic recessive ratio. These segregations on cultivar 5534 and Lr10 fit a ratio for two gene pairs in common. The F₂ cultures segregated for two recessive genes for virulence on the durum cultivars Crosby, Golden Ball, Leeds, Rolette, and Stewart 63. Segregation for virulence on the durums Cando and Wells and the T. aestivum line Lr3 fit a ratio for two recessive genes with either or both homozygous genes conditioning virulence. Segregation on the durum cultivar D6618 indicated a single dominant gene for virulence.