|Gulya Jr, Thomas|
Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 4/20/2008
Publication Date: 6/1/2008
Citation: Jan, C.C., Seiler, G.J., Gulya, T.J., Feng, J. 2008. Sunflower germplasm development utilizing wild Helianthus species. Proceedings of 17th International Sunflower Conference, June 8-12, 2008, Cordoba, Spain. p. 29-43. Interpretive Summary: Sunflower production continues to face challenges from both abiotic and biotic factors as well as from today's ever-changing market needs. The limited genetic variability in cultivated sunflower has slowed the future improvement of the crop, and has placed the crop in a vulnerable position should any major shifts of disease races or pests occur. In addition, sunflower is not always grown on prime land, but often on marginal land with minor salt and drought problems, presenting a challenge to be productive under less than ideal conditions. In order to be competitive with other premium oils in the market, the reduction of saturated fatty acids in sunflower oil will play a key role in maintaining our continuing success. Extensive collection efforts for wild Helianthus species and the regeneration of seeds at the USDA-ARS, Regional Plant Introduction Station at Ames, Iowa have greatly increased the availability of wild Helianthus seed for sunflower improvement. An overall advancement of our understanding of wild Helianthus species and improved methods of making interspecific crosses have increased the number of useful genes available from wild Helianthus species, making it possible to transfer genes that were not possible three decades ago. This report discusses the importance of wild Helianthus species and their utilization for sunflower improvement in the past and present, and show examples from our current wild species breeding program, and future prospects.
Technical Abstract: The narrow genetic base of cultivated sunflower has been broadened by the infusion of genes from the wild species, which have provided a continued source of agronomic traits for crop improvement. The genus Helianthus comprises 51 species (14 annual and 37 perennial), all native to North America. The available genetic diversity from the wild species is continuing to be used to broaden the genetic background of the crop. Recent advances in culturing of otherwise abortive interspecific hybrid embryos have proved to be highly effective for making the difficult-to-cross wild perennial Helianthus species widely available for breeding purposes, either for specific major gene transfer or for the transfer of quantitative trait genes. These techniques are discussed and illustrations are shown of how they are being used to incorporate genes from several different ploidy levels of wild perennial species into cultivated sunflower for Sclerotinia stalk rot resistance and other diseases. Significant results have been reported on the germplasm development with regard to resistance to new races of downy mildew, rust, broomrape and other major diseases. In addition, new CMS and corresponding fertility restoration genes have been continuously identified and established, together with new genes helping to improve oil quality, herbicide resistance, and salt and drought tolerance. Thus far, only a small portion of the available genetic diversity of the wild Helianthus species has been used globally. As a whole, there is no doubt that wild Helianthus species will continue to provide new genetic variability to the sunflower breeding community, helping to maintain sunflower as a viable major global oilseed crop.