Identification of Russian Wheat Aphid (Homoptera: Aphididae) Populations Virulent to the Dn4 Resistance Gene

• Published in: Journal of economic entomology 2004-06, Vol.97 (3), p.1112-1117
• Main Authors: Smith, C. Michael, Belay, Tesfay, Stauffer, Christian, Stary, Petr, Kubeckova, Irenka, Starkey, Sharon
• Format: Article
• Language: English
• Subjects: Animals; antibiosis; Aphidoidea; Aphids - pathogenicity; barley; Biological and medical sciences; biotypes; Chile; Control; crop damage; cultivars; Czech Republic; Diuraphis noxia; Dn resistance genes; Ethiopia; Fundamental and applied biological sciences. Psychology; Generalities; genes; genetic resistance; Hordeum; insect development; insect growth; insect pests; pest resistance; Phytopathology. Animal pests. Plant and forest protection; Plant Diseases - genetics; PLANT RESISTANCE; population density; Protozoa. Invertebrates; provenance; resistance-breaking populations; Russia; Triticum - genetics; Triticum aestivum; virulence; wheat
• ISSN: 0022-0493; 1938-291X
• DOI: 10.1603/0022-0493%282004%29097%5B1112%3AIORWAH%5D2.0.CO%3B2

The Russian wheat aphid, Diuraphis noxia (Mordvilko), is a serious worldwide pest of wheat and barley. Russian wheat aphid populations from Hungary, Russia, and Syria have previously been identified as virulent to D. noxia (Dn) 4, the gene in all Russian wheat aphid-resistant cultivars produced in Colorado. However, the virulence of Russian wheat aphid populations from central Europe, North Africa, and South America to existing Dn genes has not been assessed. Experiments with plants containing several different Dn genes demonstrated that populations from Chile, the Czech Republic, and Ethiopia are also virulent to Dn4. The Czech population was also virulent to plants containing the Dnx gene in wheat plant introduction PI220127. The Ethiopian population was also virulent to plants containing the Dny gene in the Russian wheat aphid-resistant ‘Stanton’ produced in Kansas. The Chilean and Ethiopian populations were unaffected by the antibiosis resistance in Dn4 plants. There were significantly more nymphs of the Chilean population on plants of Dn4 than on Dn6 plants at both 18 and 23 d postinfestation, and the Ethiopian population attained a significantly greater weight on Dn4 plants than on plants containing Dn5 or Dn6. These newly characterized virulent Russian wheat aphid populations pose a distinct threat to existing or proposed wheat cultivars possessing Dn4.