Population genetics of the binationally distributed Mission Manzanita (Xylococcus bicolor)

Kyle L. Gunther, Sula Vanderplank, Jon P. Rebman, Andres Orduño Cruz, & Lluvia Flores-Rentería, San Diego State University, San Diego Natural History Museum, San Diego Zoo Global, Centro de Investigaciones Biológicas del Noroeste

California and the Baja peninsula are home to high levels of floral abundance, diversity, and endemism. Much of this region is part of a biodiversity hotspot and therefore a conservation priority. The Mission Manzanita (Xylococcus bicolor) is endemic to this area, an ecologically and ethnobotanically important shrub, and the sole member of a monotypic genus within Ericaceae. Xylococcus bicolor is narrowly distributed from the middle of Baja California to the Los Angeles area, and has been predicted to experience up to 88% habitat loss due to climate change and development. However, little is known about its population structure, demographics, and genetic diversity, which may be useful information for conservation purposes. In order to fill this gap in knowledge, we are studying these aspects from a genetic perspective. Using a genome skimming technique to reveal thousands of single nucleotide polymorphisms, we are analyzing the population structure, genetic diversity, gene flow, and effective population sizes across the X. bicolor distribution. Preliminary results suggest the presence of intraspecific divergence and population structure, while niche models show loss of suitable habitat using climate change scenarios. We hope our study will provide useful information for land management and conservation decisions.