Mating compatibility and fertility studies in an herbaceous perennial Aster undergoing de novo domestication to enhance agroecosystems

Abstract

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.