Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: April 15, 2010
Publication Date: June 23, 2010
Repository URL: http://www.agrowebcee.net/fileadmin/content/sunflower/files/International_Symposium_Sunflower_Breeding_On_Resistance_To_.pdf
Citation: Seiler, G.J. 2010. Utilization of Wild Sunflower Species in Breeding for Disease Resistance [abstract]. International Sunflower Association Symposium "Sunflower Breeding on Resistance to Diseases," June 23-24, 2010, Krasnodar, Russia. p. 36. Available: http://www.agrowebcee.net/fileadmin/content/sunflower/files/International_Symposium_Sunflower_Breeding_On_Resistance_To_.pdf Technical Abstract: There are 51 species of wild Helianthus, 14 annual and 37 perennial. The genus Helianthus, besides constituting the basic genetic stock from which cultivated sunflower originated, continues to contribute specific characteristics for cultivated sunflower improvement. In a recent survey of 13 major crops for introduced genes from wild ancestors, sunflower ranks fifth with seven traits. It is estimated that wild species contribute 270-385 million USD per year to just the USA's sunflower industry. Much of this value is derived from resistance genes for several major diseases including rust, downy mildew, Verticillium wilt, powdery mildew, Phomopsis stem canker, Sclerotinia wilt, charcoal rot, Phoma black stem, and the parasitic weed broomrape. The frequency of downy mildew resistance genes in the wild annual species is high with dominant genes controlling single specific races being the most common, while multiple race resistance to all know races is found in only two populations of H. argophyllus. The frequency of rust resistance genes is also high in wild annual species with many populations containing rust-resistant plants, but complete resistance or total susceptibility is rarely found. Helianthus tuberosus has provided disease resistance genes for over 50 years. It has been particularly useful for stem-infecting diseases such as Sclerotinia stalk rot, Phomopsis stem canker, Phoma black stem, and charcoal rot. The perennial species have also been useful for providing resistance genes for broomrape, where most of the perennial species have been reported to have immunity to the parasite. Significant progress has been made in collecting and preserving the wild Helianthus species germplasm increasing the available genetic diversity, but only a small portion of that diversity has been exploited for sunflower improvement. This germplasm will be important in the future as new races of diseases evolve and new diseases appear.