Conservation Genomics and Species Delimitation of Mascarene Ebony trees (Diospyros)

Alexander G. Linan, Porter P. Lowry II, Allison Miller, George E. Schatz, Jean-Claude Sevathian, Christine E. Edwards, Saint Louis University, Missouri Botanical Garden, Institut de Systématique, Évolution et Biodiversité (ISYEB), Centre National de la Recherche Scientifique/Muséum National d’Histoire Naturelle/École, Pratique des Hautes Études, Université Pierre et Marie Curie, Sorbonne Universités, Donald Danforth Plant Science Center

The ebony and persimmon genus (Diospyros) is a diverse group of largely tropical trees and shrubs, comprising >800 species, many of which are poorly known, and/or are of dire conservation concern. Some of the most endangered members of the genus are endemic to islands of the Western Indian Ocean. The Mascarene Islands, comprising the islands Reunion, Rodrigues, and Mauritius is located east of Madagascar, and harbor 14 endemic species of Diospyros. Most of the species diversity is endemic to Mauritius are of dire conservation concern with the majority of species listed as either Critically Endangered or Endangered by IUCN Red List assessments. Despite their conservation status, nothing is known about patterns of genetic diversity or whether these sympatrically distributed and closely related species represent distinct genetic units. In this study we conducted population level sampling on all extant species of endemic Mascarene Diospyros and genotyped samples using 2bRAD seq in order to: 1) clarify species limits within the group, 2) determine and compare levels of genetic diversity across species and, 3) assess patterns of genetic structure within species and prioritize populations for conservation efforts. We found the morphologically described species correspond to unique genetic units despite the presence of hybrids and provide recommendations for future/ongoing conservation efforts.