This award supports exploration of genetic and species diversity in chili peppers and their close relatives in the nightshade family (Solanaceae). Chili peppers, used in chili powder, salsa, and hot sauce, are a major crop worth approximately $30 billion worldwide, and one of the most important vegetable spices in the world. Chili peppers evolved in the New World (Mexico, Central and South America), and are a well-known ingredient in Latin American cuisine. However, they are now an important component of traditional dishes in most Asian and some African and Pacific Island countries. Despite this significance, the species and genetic diversity in wild chili peppers and their relatives has not been well studied. Surprisingly, many of the wild relatives grow in wet rainforests and do not have spicy fruits. Understanding this diversity and the relationships among peppers and their relatives will provide important information on domestication and the genes controlling useful traits for chili pepper breeding and research. This award will fund field work to visit populations of wild chili peppers and their relatives, investigate their genetic diversity, and build an evolutionary tree showing their relationships. Illustrated descriptions for all the species in this group will be provided online, along with tools to help in their identification. The team of investigators who will carry out this project, located in Utah, California, Argentina, and England, are all experts on this group of plants. Along with realizing the scientific goals of this study, they will convey the excitement and discovery of botanical research to a wide audience through blogs from the field, media releases, and K-12 outreach at a children's garden at UC Davis. This project will advance knowledge by providing complete, detailed taxonomic and phylogenetic information on the pepper genus (Capsicum) and its sister genus (Lycianthes). Both genera lack modern, species-level treatments and robust, well-sampled phylogenies. These data are fundamental to future systematic and crop improvement work on both genera and will stimulate the examination of other biological questions such as the evolution of chili pepper pungency and key innovations such as anther pores in the Solanaceae. This project will assemble systematic information on Capsicum and Lycianthes, delimiting species, discovering new taxa, and clarifying species ranges. This is especially important in many of the wild Capsicum taxa that are narrow endemics in critically endangered ecosystems. The taxonomic component of this project will be available on-line and use the data structures and website resources created in a previously NSF-funded initiative on the genus Solanum (Solanaceae Source). All data will be freely available for re-use. The taxonomic and nomenclatural information will also be shared with aggregator institutions such as Encyclopedia of Life. Molecular data will be acquired using next-generation sequencing techniques by combining the expertise of taxonomists with that of a specialist in pepper breeding and genomics. These data will be used to produce the most densely sampled phylogenies of Capsicum and Lycianthes to date. The genomic information and data generated during this project may have broad applicability in plant phylogenetics and the improvement of other solanaceous crops. This research will solve the complex and uncertain relationship between the two genera and provide the framework for the study of evolution and domestication in one of the world?s most important vegetable spices. Eventually this work may build a better pepper.
