Geographical distance and barriers explain population genetic patterns in an endangered island perennial

Abstract

Oceanic islands are of particular importance for the conservation of global diversity. Rare island plants with small population sizes and unique genetic patterns resulting from prolonged evolutionary isolation are usually extremely fragile. Therefore, research dedicated to conservation of these plants should consider threat factors, population structure and genetic diversity to enable the development of scientifically supported management programs. For Lactuca watsoniana, Azorean lettuce, we performed a comprehensive population genetic study, unravelling genetic diversity patterns intrinsically related to geographical distances and barriers. Our study showed that genetic diversity levels in island plants can be relatively high even for rare plants.

Phylogenetic relationships and phylogeography of relevant lineages within the complex Campanulaceae family in Macaronesia

“…Sequences of taxa labeled with "(Gb)" were obtained on GenBank (Table S2) archipelagos, acting as effective barriers to dispersal and promoting allopatric speciation (Schaefer et al, 2011). However, within-island diversification (i.e., in A. vidalii) might be due to complex topographies and long eruptive episodes that happened on these islands (Borges Silva et al, 2016;Brown, Hoskisson, Welton, & Baez, 2006;Dias, Moura, Schaefer, & Silva, 2016;Juan, Emerson, Oromí, & Hewitt, 2000;Silva et al, 2015).…”

Northern Hemisphere disjunctions in Lactuca (Cichorieae, Asteraceae): independent Eurasia to North America migrations and allopolyploidization

“…The North American members of the L. canadensis clade are strong dispersers and their broad distribution would facilitate dispersal to the Azores. Potentially two or more introductions to the Azores would have occurred, thereby contributing to the high levels of intra-specific genetic variation in L. watsoniana observed by Dias & al. (2016;see also Stuessy & al.…”

Overexploitation and anthropogenic disturbances threaten the genetic diversity of an economically important neotropical palm

“…The influence of these factors vary with life-history traits and include effective population size, mode of reproduction, and breeding systems (Degen and Roubik 2004), as well as the geographical range of the species (Rouger and Jump 2014). Furthermore, gene flow also has an impact on genetic structure within and among populations (Provan et al 2008;Araújo et al 2017), which is influenced not only by the ability of dispersers and pollinators to reach other populations, but also by geographical barriers that may exist between populations (Dias et al 2016).…”