|MAREK, LAURA - Iowa State University|
Submitted to: Helia
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/17/2016
Publication Date: 12/3/2016
Citation: Seiler, G.J., Marek, L.F. 2016. Collection of wild Helianthus anomalus and deserticola sunflower from the desert southwest USA. Helia. 39(65):139-155.
Interpretive Summary: Crop wild relatives of sunflower, which include the progenitors of the crop as well as other species more or less closely related to them, have been undeniably beneficial to sustaining the modern sunflower crop by providing plant breeders with an extensive pool of useful genetic resources dating back 100 years. Genetic resources are the biological basis of global food security, and acquisition through exploration is the initial step in the germplasm conservation and utilization process. The need for germplasm exploration is driven by the priority needs of the crop for new traits. The objective of the study was to undertake an exploration to the desert southwest USA in Utah and Arizona to collect wild sand and desert sunflowers, currently underrepresented in the USDA-ARS, National Plant Germplasm System (NPGS) sunflower crop wild relatives gene bank. The addition of 10 sand sunflower and five desert sunflower populations to the NPGS wild sunflower germplasm collection represents the first germplasm of these species collected from Utah and Arizona in almost 15 years. These species are native to drought-prone environments and are potential sources of drought resistance traits for improving crop productivity under water-limiting conditions, providing the opportunity to study in more detail the physiological processes that are involved in the survival mechanisms of these desert-inhabiting species. Preservation of this germplasm for future generations will be important to combat emerging pests and environmental challenges, helping to maintain sunflower as a viable and competitive global crop.
Technical Abstract: Genetic resources are the biological basis of global food security. Collection and preservation of wild relatives of important crop species such as sunflower provide the basic foundation to improve and sustain the crop. Acquisition through exploration is the initial step in the germplasm conservation process. There are 53 species of wild Helianthus (39 perennial and 14 annual) native to North America. An exploration covering 3700 km to the desert southwest United States in mid-June of 2015 led to the collection of five populations of H. deserticola (desert sunflower) and 10 H. anomalus (sand sunflower) accessions. All populations were collected throughout the broad distributional range of the species. Based on sand sunflower’s occurrence in desert sand dune habitats of Utah and Arizona, it frequently has been recognized as drought tolerant, with the largest achenes of any wild species and relatively high oil concentration potential, and thus is a candidate for improving cultivated sunflower. Desert sunflower is a xerophytic annual species found in sandy soils underlain with clay soils on the floor of the Great Basin Desert in small populations in western Nevada, west central Utah, and along the border of Utah and Arizona. Population size, habitat, soil type, seed set, the presence of diseases and insects, and other wild sunflower species located near the collection sites were recorded for each population. This germplasm will be important now and in the future as a genetic resource for the global sunflower crop and at the same time conserve it for future generations.