Hibiscus nextRAD-seq conservation genomics

<p>The Neches River Rose Mallow (<i>Hibiscus dasycalyx</i>) is a rare wildflower endemic to Texas that is federally protected in the US. While previous work suggests that <i>H. dasycalyx</i> may be hybridizing with its widespread congeners, the Halberd-leaved Rose Mallow (<i>H. laevis</i>) and the Wolly Rose Mallow (<i>H. moscheutos</i>), this has not been studied in detail. We evaluated the relative threats to <i>H. dasycalyx</i> posed by hybridization with <i>H. laevis</i> and <i>H. moscheutos</i> by 1) examining their relatedness to one another via modern phylogenomic methods, 2) examining the species' ecological (dis)similarities to one another using ecological niche modeling, and 3) looking for genomic evidence of hybridization among the three species. Our results suggest that <i>H. dasycalyx</i> is very closely related and ecologically similar to <i>H. laevis</i>, and suggest that <i>H. laevis</i> is interbreeding with <i>H. dasycalyx</i> in the wild. Conversely, <i>H. moscheutos</i> appears to be more distantly related to <i>H. dasycalyx</i> and more ecologically dissimilar, and the two are most likely not hybridizing. For these reasons, we believe that <i>H. laevis</i> poses a greater threat to <i>H. dasycalyx</i> than <i>H. moscheutos</i>. We offer some hypotheses as to why <i>H. dasycalyx</i> and <i>H. laevis</i> are coming into secondary contact where hybridization can occur.</p>