Oral Paper

         Phylogenomics

Patterns of morphological and molecular variation provide insights into the systematics and evolution of Rhododendron’s ‘Hardy Mountaineers’

Presenting Author
Ryan Fuller
Description
The Hengduan Mountain biodiversity hotspot of south-central China is an important region of species diversity for the genus Rhododendron (Ericaceae). One alpine clade, subsection Lapponica, is comprised of 40 species, of which, 34 are endemic to China. While some species in the group display consistent morphological identity across their geographic range, many traditional taxonomic characters hold little value for delimitation, thus challenging identification and creating issues for deeper evolutionary analyses. Of particular interest are the peltate scales of the leaves, which have traditionally been used for clustering phenotypes into species’ bins. Additionally, polyploid occurrence in Lapponica is above average for the genus but its extent remains relatively uncharacterized at the inter-and-intraspecific level. This study has three aims: 1) test species relationships based on traditional morphological hypotheses using genomic data, 2) to characterize ploidy levels across species and geography, and 3) infer polyploid origins using molecular sequencing and morphological analyses. Here, we present an update to ongoing analyses of this group including a diploid phylogeny based on hundreds of molecular loci, highlight potential polyploid species and their origins, and show results of the morphometric analyses of leaves and flower traits and how their patterns relate to phylogeny and biogeography.