De novo domestication has received recent attention because of the potential to produce new crop species with additional agroecosystem functions and useful products for climate-resilient agricultural systems of the future. However, there are often traits in wild species that make them difficult to domesticate. One key domestication trait selected by early farmers and modern plant breeders in many crops is the ability to self-pollinate. Benefits include higher seed set and more reliable seed production, as well as more efficient selection during breeding because it allows for unmasking of recessive traits and enforcement of favorable gene interactions. Similarly, interspecific hybridization has been used to add to the genetic diversity of many crop species. We evaluated self-pollination and interspecific hybridization in Silphium integrifolium and S. perfoliatum to learn the extent of possible gene flow between the species and its usefulness in cultivar development and the potential for fixation of favorable domestication genes by self-pollination. Our results indicate that Silphium interspecific hybrids can be easily developed, potentially facilitating movement of otherwise invariable traits from one species to another. Further, we showed, for the first time, that self-pollination is also possible in both species and their interspecific hybrids, but the rate varies among genotypes. This has profound implications in optimizing plant breeding methods for the study and improvement of these species and adds more evidence to our understanding of mating systems in Asteraceae, an underutilized family of plants with great potential for additional domesticated species.

Sclerotinia diseases and Phomopsis stem canker, among the most serious diseases threatening the success of sunflower (Helianthus annuus L.) production across the world, have been of increasing concern in recent history, and there is a need for additional inbred lines with resistance to these diseases. While breeding new lines capable of thriving in agricultural landscapes riddled with these widespread diseases, it is essential that lines also exhibit other desirable traits such as high yield potential, satisfactory fatty acid composition (e.g., high oleic acid), and herbicide tolerance (e.g., to imidazolinones), along with overall agronomic performance suitable to the northern Great Plains climate in the United States, and similar climates across other continents. A maintainer inbred germplasm line, HA 482 (Reg. no. GP-364, PI 690015), and two restorer inbred germplasms, RHA 483 (Reg. no. GP-365, PI 690016) and RHA 484 (Reg. no. GP-366, PI 690017), have been developed with the pedigree breeding method, evaluated through the use of testcross hybrid trials for both disease resistance and agronomic traits, and released by the USDA-ARS, Fargo, ND. All three lines have high oleic acid composition in the seed oil and exhibit resistance to Sclerotinia and Phomopsis stem canker, and both RHA 483 and RHA 484 are imidazolinone tolerant.

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