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United States Department of Agriculture

Agricultural Research Service

Title: Recent Explorations to Recover Seed of Rare and Interesting Helianthus Species and Future Explorations

Authors
item Seiler, Gerald
item Gulya Jr, Thomas

Submitted to: Proceedings Sunflower Research Workshop
Publication Type: Proceedings
Publication Acceptance Date: March 31, 2005
Publication Date: April 15, 2005
Citation: Seiler, G.J., Gulya Jr, T.J. 2005. Recent explorations to recover seed of rare and interesting Helianthus species and future explorations. Proceedings Sunflower Research Workshop. 27th Sunflower Research Workshop, January 12-13, 2005, Fargo, ND. Available: http://www.sunflowernsa.com/research/research-workshop/documents/Seiler_RecoveringSeeds_05.pdf

Interpretive Summary: The disappearance of habitat for several wild sunflower species is of concern for the long-term survival of the sunflower industry because wild species are the ancestors of the crop. 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 desirable agronomic traits. The genus Helianthus consists of 51 species (14 annual and 37 perennial), all restricted to North America. Therefore, it is imperative that as many natural populations of wild species as possible be collected and preserved in germplasm collections for future use. The utility of a germplasm collection is dependent upon the genetic diversity of each species i.e., the number of accessions per species and the availability for research. Several of wild sunflower species are rare, threatened, or endangered due to their restricted distribution and the encroachment of human activities destroying their habitats. Unfortunately, due to the demand for the seed of several wild sunflower species and the difficulties of regenerating the original populations collected over 20 years ago, seed has not been available for research. The objective of this research was to collect seeds (> 2,000 seeds per population) from as many populations as possible of annual serpentine sunflower, annual confederate daisy sunflower, and perennial California sunflower, Eggert’s sunflower, Schweinitz’s sunflower, whorled sunflower and Smith’s sunflower and make them available for future research for the improvement of cultivated sunflower. Three explorations were undertaken to collect wild sunflower germplasm. The first exploration for annual serpentine sunflower took place in September, 2002. It covered 2600 miles in California from the Coastal Range (Napa County), north to the Oregon border, to the western foothills of the Sierra Nevada Mountains, and south to Tuolumne County. This twelve-day exploration trip resulted in the collection of 26 populations of serpentine sunflower with over 2,000 seeds for each population. The second exploration for perennial California sunflower took place September, 2003 covering 2660 miles in central and southern California. This ten-day exploration resulted in the collection of 12 populations with over 2,000 seeds for each population. The last exploration for Eggert’s, Schweinitz’s, whorled, Smith’s and confederate daisy sunflower was undertaken in October, 2003. It covered 2865 miles in the states of Georgia, Tennessee, North and South Carolina, and Alabama. This exploration to the southeastern US was a 12 day trip. It resulted in the collection of 13 populations of Eggert’s sunflower, 14 populations of Schweinitz’s sunflower, one populations of Smith’s sunflower, and two populations of Whorled sunflower, and eight populations of the annual confederate daisy sunflower. None of these five species were previously available for research. There are still several gaps in the wild sunflower germplasm collection. Currently 22 species of wild sunflower are listed as unavailable since the seed quantity is below the 2,000 seed minimum threshold limit, below which seed distribution stops pending either seed regeneration or recollection. Explorations will be planned according to the perceived needs of the sunflower community. Assuming one collecting trip per year, it may be possible to collect seed of all remaining 22 species within the next decade.

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 desirable agronomic traits for improving cultivated sunflower. The genus Helianthus consists of 51 species (14 annual and 37 perennial), all native to North America. The utility of a germplasm collection is dependent upon the genetic diversity of each species i.e., the number of accessions per species and the availability for research. Several of wild sunflower species are rare, threatened, or endangered due to their restricted distribution and the encroachment of human activities destroying their habitats. Unfortunately, due to the demand for the seed of several wild sunflower species and the difficulties of regenerating the original populations collected over 20 years ago, seed has not been available for research. The objective of this research was to collect seeds (> 2,000 seeds per population) from as many populations as possible of Helianthus exilis, Helianthus californicus, Helianthus eggertii, Helianthus schweinitzii, Helianthus verticillatus, Helianthus smithii and Helianthus porteri and make them available for future research for the improvement of cultivated sunflower. The first exploration for serpentine sunflower took place in September, 2002. It covered 2600 miles in California from the Coastal Range (Napa County), north to the Oregon border, to the western foothills of the Sierra Nevada Mountains, and south to Tuolumne County. This twelve-day exploration trip resulted in the collection of 26 populations of H. exilis with over 2,000 seeds each. The second exploration for perennial California sunflower took place September, 2003 covering 2660 miles in central and southern California. This ten-day exploration resulted in the collection of 12 populations of perennial H. californicus with over 2,000 seeds for each population. The last exploration for Eggert’s, Schweinitz’s, whorled, Smith’s and confederate daisy sunflower was undertaken in October, 2003. It covered 2865 miles in the states of Georgia, Tennessee, North and South Carolina, and Alabama. This exploration to the southeastern US was a 12 day trip. It resulted in the collection of 13 populations of H. eggertii, 14 populations of H. schweinitzii, one populations of H. smithii, and two populations of H. verticillatus, and eight populations of H. porteri. None of the five species were previously available for research. There are still several gaps in the wild sunflower germplasm collection. Currently 22 species of Helianthus are listed as unavailable since the seed quantity is below the 2,000 seed minimum threshold limit, below which seed distribution stops pending either seed regeneration or recollection. Explorations will be planned according to the perceived needs of the sunflower community. Assuming one collecting trip per year, it may be possible to collect seed of all remaining 22 species within the next decade.

Last Modified: 10/30/2014
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