Patterns of genetic divergence of three Canarian endemicLotus(Fabaceae): implications for the conservation of the endangeredL. kunkelii

Abstract

We examined data for 11 allozyme loci in 14 populations that represent the distribution of the endangered Lotus kunkelii, the narrowly distributed L. arinagensis (both endemic to Gran Canaria), and the broad-ranging L. lancerottensis (endemic to the easternmost Canary Islands, Fuerteventura and Lanzarote) to explore and construe patterns of genetic variation and use this data to assess the controversial taxonomic status of L. kunkelii relative to L. lancerottensis. While L. kunkelii maintains low levels of variation, presumably as a consequence of prolonged inbreeding due to very low population size and sharp geographic isolation, the other two taxa have much higher indicators of polymorphism than those reported for other oceanic island endemics. Lotus arinagensis has the highest genetic polymorphism and the lowest interpopulation differentiation, presumably because of its considerable antiquity and habitat stability, despite recent fragmentation. The high interpopulation differentiation in L. lancerottensis is attributed to the Atlantic acting as a barrier, reducing gene flow within islands. Evolutionary analysis of the allozyme evidence indicates that L. kunkelii is genetically closer to L. arinagensis than to L. lancerottensis, thereby dispelling the taxonomic uncertainty and supporting L. kunkelii as a distinct species, warranting legal protection in the forthcoming catalog of threatened Canarian species.

Conservation genetics of the endangered endemic Sambucus palmensis Link (Sambucaceae) from the Canary Islands

“…Understanding the level and apportionment of genetic diversity within and among populations is especially important for the conservation of island endemics because being island plants may make them even more susceptible to extinction (Frankham 1998;Prohens et al 2007). In this sense, there are growing conservation genetics studies on Canary endemic flora Batista et al 2004;Kim et al 2005;González-Pérez et al 2004a, 2008, 2009aOliva-Tejera et al 2006;MoraVicente et al 2009;Suarez-García et al 2009). Also, neutral hypervariable markers are useful in estimating the relative evolutionary importance of genetic factors such as mutation rates, gene flow, and genetic drift (González-Pérez et al 2004b, 2009b, 2009cSegarra-Moragues et al 2005;Van Geert et al 2008).…”

Genetic Diversity of the Japanese Wood Pigeon,Columba janthina, Endemic to Islands of East Asia, Estimated by Newly Developed Microsatellite Markers

“…We also agree with the recommendation of Crandall et al (2000) for measuring genetic differentiation on both historical and recent time scales. The magnitude of recent genetic differentiation is expected to vary among taxa due to differences in life history and dispersal abilities and thus should be considered with reference to the level of genetic differentiation between species, subspecies, and populations in other parts of the taxon's range (Oliva-Tejera et al 2006). Traditionally, phylogeographic studies use mitochondrial, chloroplast, or nuclear DNA sequence data to infer deeper historical relationships among populations, whereas landscape genetic studies use microsatellite loci to quantify genetic structure on more recent time scales.…”

Conservation of oceanic island floras: Present and future global challenges

“…Molecular population genetic or phylogenetic investigations are contributing to more refined insights into the population biology and systematics of endemics in several archipelagos (e.g. Crawford et al, 1987;Baldwin et al, 1991;Francisco-Ortega et al, 1996;Carine et al, 2004;Nuez et al, 2004;Ruiz et al, 2004;Moore et al, 2006;Archibald et al, 2006;Oliva-Tejera et al, 2006;Díaz-Pé rez et al, 2008;Maunder et al, 2008;Andrus et al, 2009;Gonzá lez-Pé rez et al, 2009). Currently, a sample of the endemic flora of Garajonay National Park (La Gomera, Canaries) is being used to test the potential usefulness of cpDNA sequences in complementing morphological variables for the identification of the whole Canarian Flora (Caujapé -Castells et al, 2007a, b).…”