GETTING TO THE ROOTS OF PUNGENCY: THE TAXONOMY AND PHYLOGENY OF LYCIANTHES AND CAPSICUM (CAPSICEAE, SOLANACEAE)

BARBOZA, G. E.; DEAN, E.; BOHS, L.; KNAPP, S.; VAN DEYNZE, A.

Davis

Congreso; The 13th Solanaceae Conference 2016, SolGenomics: From Advances to Applications; 2016

University of California

One of the major clades in the Solanaceae is the Capsiceae, consisting of the genera Capsicum and Lycianthes. Capsicum, with about 35 exclusively Neotropical species, includes the chili and bell peppers and their relatives. Capsicum is unique in that the fruits of most species contain pungent capsaicinoids that deter predation by mammals and reduce microbial attack while permitting dispersal by birds. Capsaicinoids are known only from the genus Capsicum, and their evolution, biosynthesis, genetic control, and ecological significance are of great biological and practical importance. Lycianthes contains 150 to 200 species, about 80% of them neotropical and 20% from tropical Asia and the Pacific. Lycianthes fruits lack capsaicinoids andvarious species are eaten by humans as wild food sources. Morphologically, Capsicumand Lycianthes share an unusual calyx structure but are differentiated by nectary and anther structure. Capsicum anthers open bylongitudinal slits, as do most other Solanaceae, and the flowers have a nectaryat the base of the ovary. Lycianthes anthers open by terminal pores andthe flowers lack a nectary. We constucted a phylogeny based on a four-genedataset to investigate the roots of pungency in the Capsiceae and therelationship between Lycianthes and Capsicum. Capsicum forms a well-supported monophyletic group and Lycianthes is paraphyletic, but resolution and support are low in the backbone of the tree. To produce a more definitive phylogeny, we are using exome capture and sequencing to characterizethe diversity in orthologous genes across Lycianthes and Capsicum species. During year one of the project, transcriptomes derived from the root and leaf tissue of diverse species from both genera were sequenced. Sequences from approximately 14,000genes represented in the transcriptomes of three Lycianthes species and one Capsicum species were selected for probe design for exome capture. From this set, about 3000 genes were selected to representuniform spacing across the genome and genes of interest. In addition to phylogeny reconstruction, this project will produce online species descriptions and taxonomic synonymy for all New World species of the two genera. Species descriptions will be posted on our Solanaceae Source website (http://solanaceaesource.org/).