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A 10-day trip, encompassing 4600 km in the southeastern USA states of Tennessee, North Carolina, South Carolina, Georgia and Alabama, was made in October, 2003. Our primary objective was to locate populations of Helianthus eggertii, then on the USDI, Fish and Wildlife Service Threatened and Endangered Species list, and H. verticillatus, a candidate for endangered species status. Helianthus eggertii has since been de-listed (August 2005). An additional objective was to collect seeds of H. porteri, a species reclassified from Viguiera porteri, which is endemic to granite rock outcrops in Georgia. We collected seeds from 27 populations of the above three species plus three additional species, H. angustifolius, H. atrorubens, and H. smithii. Seed was deposited with the USDA-ARS North Central Regional Plant Introduction Station at Ames, Iowa (NCRPIS) from which 24 of the 27 collections are available for distribution. The three 'target' species were represented by 13 collections of H. eggertii, eight of H. porteri, and two of H. verticillatus; none of the three species were previously available from the NCRPIS sunflower collection. The availability of seed of these three species will allow researchers around the world the opportunity to investigate the potential of these wild Helianthus species to contribute useful traits to cultivated sunflower. Complete collection data has been loaded into the USDA-ARS Germplasm Resource Information Network (GRIN), and is available on the internet (www.ars-grin.gov). [ABSTRACT FROM AUTHOR]

The ability of some sunflower species to survive and thrive in shifting sand dunes with an annual precipitation of 50 mm could be of value for cultivated sunflower, a crop often grown in arid regions. The genus Helianthus comprises 51 species and 19 subspecies, with 14 annual and 37 perennial species, all native to North America. The objective of this study was to collect achenes from as many populations as possible of desert species, specifically annual H. anomalus, H. deserticola, H. niveus ssp. canescens, and perennial H. niveus ssp. tephrodes from the desert southwestern USA and make them available for future research and improvement of cultivated sunflower. The first exploration for H. anomalus and H. deserticola took place from September 16 to 23, 2000, covering 4100 km in three states, Utah, Arizona, and Nevada; while the second exploration concentrated on H. deserticola populations in west central Nevada, taking place between June 20 to 23 and August 15 to 18, 2005. The third exploration for H. niveus ssp. tephrodes took place from February 26 through March 5, 2005, covering 2200 km in southern California and adjacent Arizona. Only one population of H. deserticola from Utah and two populations of H. anomalus from Utah were collected in 2000. The 2005 exploration in Nevada resulted in the collection of achenes from 13 populations of H. deserticola. In 2005, five populations of H. niveus ssp. tephrodes were collected from the Alogodones Dunes in California. One population of H. niveus ssp. canescens was collected from Yuma, Arizona, near the US-Mexico border, with three additional populations collected from the Pinta Sands area of Arizona, which is the northernmost extension of the Gran Desierto of Sonora, Mexico. Achene samples of each collection are maintained and distributed from the USDA-ARS National Plant Germplasm System, North Central Regional Plant Introduction Station, Ames, Iowa. The limited number of desert species populations collected will provide basic germplasm for further research dealing with improving drought tolerance in cultivated sunflower. [ABSTRACT FROM AUTHOR]

ABSTRACT Sunflower mosaic is caused by a putative member of the family Potyviridae. Sunflower mosaic virus (SuMV) was characterized in terms of host range, physical and biological characteristics, and partial nucleotide and amino acid sequence. Cells infected with SuMV had cytoplasmic inclusion bodies typical of potyviruses. Of 74 genera tested, only species in Helianthus, Sanvitalia, and Zinnia, all Asteraceae, were systemic hosts. Commercial sunflower hybrids from the United States, Europe, and South Africa were all equally susceptible. The mean length of purified particles is approximately 723 nm. The virus was transmitted by Myzus persicae and Capitphorus elaegni, and also was seedborne in at least one sunflower cultivar. Indirect enzyme-linked immunosorbent assay tests with a broad-spectrum potyvirus monoclonal antibody were strongly positive. SuMV-specific polyclonal antisera recognized SuMV and, to a lesser extent, Tobacco etch virus (TEV). When tested against a panel of 31 potyvirus-differentiating monoclonal antibodies, SuMV was distinct from any potyvirus previously tested. SuMV shared four epitopes with TEV, but had a reaction profile more similar to Tulip breaking virus (TBV). SuMV did not possess epitopes unique only to TBV. The predicted coat protein had a molecular weight of 30.5 kDa. The 3' end of the virus genome was cloned and sequenced. Phylogenetic analysis of the coat protein amino acid sequence revealed that SuMV is a distinct species within the family Potyviridae, most closely related to TEV.