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Genetics

Gene Pu₆: A New Gene in Sunflower for Resistance to Puccinia helianthi. S. M. Yang, Research plant pathologist, U.S. Department of Agriculture, Agricultural Research Service, Foreign Disease-Weed Science Research, Ft. Detrick, Frederick, MD 21701; W. M. Dowler(2), and A. Luciano(3). (2)Supervisory plant pathologist, U.S. Department of Agriculture, Agricultural Research Service, Foreign Disease-Weed Science Research, Ft. Detrick, Frederick, MD 21701; (3)Senior breeder, Argentina Criadero de Semillas, S.A., Parana, Entre Rios, Argentina. Phytopathology 79:474-477. Accepted for publication 21 November 1988. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1989. DOI: 10.1094/Phyto-79-474.

Studies were conducted to determine the genetic basis of resistance of sunflower (Helianthus annuus) inbred line P386 to Puccinia helianthi. This study showed that P386 carries a single dominant gene conditioning resistance to the four North American (NA) races of P. helianthi. We propose the gene symbol Pu_n, instead of R_n, to designate the sunflower genes for resistance to P. helianthi, and the name Pu₆ for the resistance gene in P386. This gene in P386 was different from the resistance gene R₁ (Pu₁) in CM 90RR, conferring resistance to NA races 1 and 2, and gene R₂ (Pu₂) in CM 29-3, conferring resistance to NA races 1 and 3. The resistance gene in P386 was also different from gene R₄ (Pu₄) in the sunflower inbred line HAR₃ and gene R₅(Pu₅) in HAR₂.

Additional keywords: inheritance, rust.