Submitted to: International Crop Science Congress Proceedings
Publication Type: Proceedings
Publication Acceptance Date: April 15, 2004
Publication Date: September 26, 2004
Citation: Seiler, G.J. 2004. Wild Helianthus anomalus and H. deserticola from the desert southwest USA: a potential source of stress genes for cultivated sunflower. International Crop Science Congress Proceedings. Available: http://www.cropscience.org.au/icsc2004/poster/1/1/415_seilergj.htm 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. Therefore, it is imperative that as many natural populations of wild species as possible be collected and preserved in germplasm collections for future use. There has been an increased interest in breeding sunflower for drought tolerance. Anomalus sunflower (Helianthus anomalus) and desert sunflower (H. deserticola) are excellent candidates for drought tolerance genes based on their adaptation to desert environments. Unfortunately, due to the demand for the seed of these species and the difficulties of regenerating the original populations, seed has not been available for research for almost 20 years. The objective of the present study was to undertake an exploration to the desert southwest U.S. to collect seeds of the two desert species for the USDA-ARS sunflower germplasm collection and make them available for further research. The sunflower exploration covered 2550 miles in Utah, Arizona, and Nevada, during September of 2000. It was an extremely dry year, with no evidence of either species being present in many of the fragile sandy habitats visited 20 years ago. For whatever reason, only three populations had plants with seeds for collection in 2000, one population of the desert sunflower and two populations of the anomalous sunflower. The anomalous sunflower has the largest seed and the highest oil concentration of any of the wild sunflower species. This will facilitate the breeding process when the wild germplasm is introgressed into cultivated germplasm for further screening for drought tolerance traits. The addition of these populations of wild species to the wild sunflower germplasm collection will insure their preservation for the future, and will greatly increase the available genetic diversity for improving the cultivated sunflower, keeping it a viable and competitive global crop.
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. Helianthus anomalus is a wild annual species adapted to sandy dunes of the southwest USA. Helianthus deserticola is another wild annual species adapted to high desert areas of the same region. The adaptation of these species to their harsh habitats allows the potential to exploit these traits for improving stress tolerance in the cultivated sunflower crop. Since no seed of these species was available in the USDA-ARS Sunflower Germplasm Collection, an exploration was undertaken in September, 2000 to collect populations for future research. Due to an extremely dry year in 2000, only two populations of H. anomalus and one H. deserticola were collected. These collections represent the first populations of these species available in the sunflower collection in over 20 years. Future research calls for introgression of the wild species into cultivated sunflower and evaluating the progeny for ecophysiological characteristics.