Molecular phylogenetics of the Macaronesian‐endemic genus Bystropogon (Lamiaceae): palaeo‐islands, ecological shifts and interisland colonizations

Abstract

A molecular phylogenetic study of Bystropogon L'Her. (Lamiaceae) is presented. We performed a cladistic analysis of nucleotide sequences of the internal transcribed spacers (ITS), of the nuclear ribosomal DNA, and of the trnL gene and trnL-trnF intergenic spacer of the chloroplast DNA. Bystropogon odoratissimus is the only species endemic to the Canary Islands that occurs in the three palaeo-islands of Tenerife. This species is not part of an early diverging lineage of Bystropogon and we suggest that it has a recent origin. This phylogenetic pattern is followed by most of the species endemic to the palaeo-islands of Tenerife. The two sections currently recognized in Bystropogon form two monophyletic groups. Taxa belonging to the section Bystropogon clade show interisland colonization limited to the Canary Islands with ecological shifts among three ecological zones. Taxa from the section Canariense clade show interisland colonization both within the Canary Islands and between the Canary Islands and Madeira. Speciation events within this clade are mostly limited to the laurel forest. The genus has followed a colonization route from the Canaries towards Madeira. This route has also been followed by at least five other plant genera with species endemic to Macaronesia. Major incongruences were found between the current infrasectional classification and the molecular phylogeny, because the varieties of Bystropogon origanifolius and Bystropogon canariensis do not form two monophyletic groups. The widespread B. origanifolius appears as progenitor of the other species in section Bystropogon with a more restricted distribution.

Genetic Variability and Differentiation Among Populations of the Azorean Endemic Gymnosperm Juniperus brevifolia: Baseline Information for a Conservation and Restoration Perspective

“…Surviving populations were small and presumably subject to genetic drift. Moreover, subsequent recolonizing events could have occurred from sources outside the island, leaving relic populations in the older parts of the islands (Trusty et al 2005). These relic populations may not have been homogenized by gene flow, in which case such patterns should be taken into consideration for conservation management activities in island biota.…”

Molecular phylogenetics of Micromeria (Lamiaceae) in the Canary Islands, diversification and inter-island colonization patterns inferred from nuclear genes

“…This can be interpreted as signature of adaptive radiation, the rapid adaptive diversification of a clade, and this has been observed for example in Bystropogon L'Hér. (Lamiaceae) (Trusty et al, 2005), Sideritis L. (Lamiaceae) (Barber et al, 2000), Gonospermum Less. and Pericallis D. Don (Asteraceae) (Francisco-Ortega et al, 2001 andJones et al, 2014 respectively), Teline Medik.…”

Genetic structure of Micromeria (Lamiaceae) in Tenerife, the imprint of geological history and hybridization on within‐island diversification

“…They also harbor unique floral elements: at least 55 plant species are endemic to at least one paleo‐island (Trusty et al. 2005): 16 on Anaga, 25 on Teno, and 14 on the smallest paleo‐island region, Adeje (Martín et al. 1999).…”