Collaborative Research: Unlocking the evolutionary history of Schiedea (carnation family, Caryophyllaceae): rapid radiation of an endemic plant genus in the Hawaiian Islands

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-------------------------------------------------------------------------------------------------------------------------------Plants exhibit a diverse array of breeding strategies, but the genetic changes and environmental conditions that lead to this diversity are poorly known. Pinpointing these genetic mutations and understanding the environmental conditions that favor changes in breeding system are of great interest to both evolutionary biologists and plant breeders. The plant genus Schiedea (carnation family, Caryophyllaceae) is only found on the Hawaiian Islands and is a model to better understand the evolution of breeding strategies in plants. Among the 32 species of Schiedea, some only breed with other individuals of the same species, others only self-fertilize, and others still are transitional between the two. Additionally, different outbreeding species of Schiedea use different pollinators, including a recently discovered moth found only in Hawaii. This project will apply cutting-edge DNA sequencing and analysis methods to reconstruct the genealogy of Scheidea and investigate the evolution of plant breeding strategies within the group. Data from this project will provide new insights into the evolution of plant breeding strategies that could be applied to crop species in the carnation family, including amaranth, rhubarb, quinoa and spinach. The project incorporates extensive opportunities for education and training at multiple levels, including high school teachers, undergraduate and graduate students, and a postdoctoral researcher. The project will produce educational videos about Hawaiian plants for posting on the internet to inform the public. Researchers will also offer public seminars about Schiedea highlighting their research findings about the group.The primary aim of this project is to reconstruct the pattern of breeding system evolution in Schiedea (Caryophyllaceae) through an integrated program of field, laboratory, and genomic studies. Nuclear genome sequencing, targeted sequence capture, and Genotyping By Sequencing (GBS) methods will be used to reconstruct a highly resolved phylogenetic tree of Schiedea, identify sources of phylogenetic conflict, and investigate patterns of introgression among taxa. The phylogenetic hypotheses developed will be used to interpret the evolution of breeding systems including transitions from hermaphroditism to dioecy, shifts from biotic to abiotic pollination, and traits associated with pollination biology (including scent and nectar production). Field studies and densely distributed Single Nucleotide Polymorphisms (SNP) markers generated by GBS will be used to test hypotheses concerning the influence of reproductive systems on gene flow, hybridization, and population genetic structure. Data obtained during this project will be applied directly to land management in Hawaii, including the establishment of wild populations of different Schiedea species.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.