Mating compatibility and fertility studies in an herbaceous perennial undergoing de novo domestication

De novo domestication has received recent attention because of the potential to produce new crop species with niche agroecosystem functions and useful products for climate-resilient agricultural systems of the future. However, there are often deficiencies in wild species that make them difficult to domesticate, including a mating system that is incompatible with preferred plant breeding methods and the lack of standing variation for certain traits requiring improvement. We evaluated a continuum of mating from self-pollination to interspecific hybridization in Silphium integrifolium and S. perfoliatum to determine the extent of possible gene flow between the species, and the potential for fixation of favorable domestication genes by self-pollination. Our results indicate that interspecific hybrids can be developed, potentially facilitating movement of traits from one species to another. Further, self-pollination is also possible in both species and their interspecific hybrids, but the rate is variable based on genotype. This has profound implications for using standard plant breeding and plant genetic methods in the study and improvement of these species.