Molecular approaches reveal speciation between red and blue flowered plants in the MediterraneanLysimachia arvensisandLysimachia monelli(Primulaceae)

Abstract

AbstractFlower colour constitutes a pivotal evolutionary force in speciation. The MediterraneanLysimachia arvensisandL. monelliare morphologically variable species having both blue or red flowered plants. Previous studies suggested thatL. arvensisplants differing in colour are diverging lineages, but this variation has not been considered in a phylogenetic context. We reconstruct the phylogenetic signal and the ancestral states of flower colour of MediterraneanLysimachiaspecies by using nuclear (ITS) and three plastid markers. Blue and red specimens are nested in two independent clades in the ITS tree, thus supporting thatL. arvensisandL. monelliare polyphyletic, whereas low phylogenetic resolution was found in plastid markers. Blue-floweredL. arvensisis reconstructed sister toL. talaveraein a monophyletic clade sister to the remainingLysimachia. Red-floweredL. arvensisis reconstructed sister to red-floweredL. monelliin a monophyletic clade sister to blue-floweredL. monelliandL. foemina. Our results suggest that colour lineages inL. arvensisandL. monelliconstitute different species, but flower colour did not promote the separation of these lineages. We propose a new name for blue-floweredL. arvensis(L. loeflingii) and a new combination for red-floweredL. monelli(L. collina).