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Progressive migration and anagenesis in Drimys confertifolia of the Juan Fernández Archipelago, Chile.

López-Sepúlveda P, Takayama K, Greimler J, Crawford DJ, Peñailillo P, Baeza M, Ruiz E, Kohl G, Tremetsberger K, Gatica A, Letelier L, Novoa P, Novak J, Stuessy TF - J. Plant Res. (2014)

Bottom Line: A common mode of speciation in oceanic islands is by anagenesis, wherein an immigrant arrives and through time transforms by mutation, recombination, and drift into a morphologically and genetically distinct species, with the new species accumulating a high level of genetic diversity.Drimys confertifolia shows a wide genetic variation within populations on both islands, and values of genetic diversity within populations are similar to those found within populations of the continental progenitor.The genetic results are compatible with the hypothesis of high levels of genetic variation accumulating within anagenetically derived species in oceanic islands, and with the concept of little or no geographical partitioning of this variation over the landscape.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Botánica, Universidad de Concepción, Casilla 160-C, Concepción, Chile.

ABSTRACT
A common mode of speciation in oceanic islands is by anagenesis, wherein an immigrant arrives and through time transforms by mutation, recombination, and drift into a morphologically and genetically distinct species, with the new species accumulating a high level of genetic diversity. We investigate speciation in Drimys confertifolia, endemic to the two major islands of the Juan Fernández Archipelago, Chile, to determine genetic consequences of anagenesis, to examine relationships among populations of D. confertifolia and the continental species D. winteri and D. andina, and to test probable migration routes between the major islands. Population genetic analyses were conducted using AFLPs and nuclear microsatellites of 421 individuals from 42 populations from the Juan Fernández islands and the continent. Drimys confertifolia shows a wide genetic variation within populations on both islands, and values of genetic diversity within populations are similar to those found within populations of the continental progenitor. The genetic results are compatible with the hypothesis of high levels of genetic variation accumulating within anagenetically derived species in oceanic islands, and with the concept of little or no geographical partitioning of this variation over the landscape. Analysis of the probability of migration within the archipelago confirms colonization from the older island, Robinson Crusoe, to the younger island Alejandro Selkirk.

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Habitats and flowers (insets) of D. confertifolia on Robinson Crusoe Island (a), D. confertifolia on Alejandro Selkirk Island (b), D. andina (c), and Drimys winteri var. winteri (d)
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Fig2: Habitats and flowers (insets) of D. confertifolia on Robinson Crusoe Island (a), D. confertifolia on Alejandro Selkirk Island (b), D. andina (c), and Drimys winteri var. winteri (d)

Mentions: Drimys confertifolia Phil., “Canelo” (Fig. 2a, b), is a protogynous (and therefore out-crossing) tree (Bernardello et al. 2001) to 15 m tall, endemic to the Juan Fernández Archipelago. Chromosomally the species is known as n = c. 43 (Sun et al. 1990), which is probably at the dodecaploid level (based on x = 7, Raven and Kyhos 1965). This is the same level reported for D. winteri (Raven and Kyhos 1965) and D. granadensis (Ehrendorfer et al. 1979). In Robinson Crusoe Island D. confertifolia is common, growing together with Myrceugeniafernandeziana (Myrtaceae), Fagara mayu (Rutaceae), and Juania australis (Arecaceae) (Greimler et al. 2002). In Alejandro Selkirk Island it occurs in patches or is scattered, not forming large pure stands, and growing together with the ferns Blechnum cycadifolium (Blechnaceae), Dicksonia externa (Dicksoniaceae), Histiopteris incisa (Dennstaedtiaceae), and Lophosoria quadripinnata (Dicksoniaceae) (Greimler et al. 2013). Drimys confertifolia is hermaphroditic and wind-pollinated (Bernardello et al. 2001), flowering from November to January (Rodríguez and Quezada 2001).Fig. 2


Progressive migration and anagenesis in Drimys confertifolia of the Juan Fernández Archipelago, Chile.

López-Sepúlveda P, Takayama K, Greimler J, Crawford DJ, Peñailillo P, Baeza M, Ruiz E, Kohl G, Tremetsberger K, Gatica A, Letelier L, Novoa P, Novak J, Stuessy TF - J. Plant Res. (2014)

Habitats and flowers (insets) of D. confertifolia on Robinson Crusoe Island (a), D. confertifolia on Alejandro Selkirk Island (b), D. andina (c), and Drimys winteri var. winteri (d)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

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Fig2: Habitats and flowers (insets) of D. confertifolia on Robinson Crusoe Island (a), D. confertifolia on Alejandro Selkirk Island (b), D. andina (c), and Drimys winteri var. winteri (d)
Mentions: Drimys confertifolia Phil., “Canelo” (Fig. 2a, b), is a protogynous (and therefore out-crossing) tree (Bernardello et al. 2001) to 15 m tall, endemic to the Juan Fernández Archipelago. Chromosomally the species is known as n = c. 43 (Sun et al. 1990), which is probably at the dodecaploid level (based on x = 7, Raven and Kyhos 1965). This is the same level reported for D. winteri (Raven and Kyhos 1965) and D. granadensis (Ehrendorfer et al. 1979). In Robinson Crusoe Island D. confertifolia is common, growing together with Myrceugeniafernandeziana (Myrtaceae), Fagara mayu (Rutaceae), and Juania australis (Arecaceae) (Greimler et al. 2002). In Alejandro Selkirk Island it occurs in patches or is scattered, not forming large pure stands, and growing together with the ferns Blechnum cycadifolium (Blechnaceae), Dicksonia externa (Dicksoniaceae), Histiopteris incisa (Dennstaedtiaceae), and Lophosoria quadripinnata (Dicksoniaceae) (Greimler et al. 2013). Drimys confertifolia is hermaphroditic and wind-pollinated (Bernardello et al. 2001), flowering from November to January (Rodríguez and Quezada 2001).Fig. 2

Bottom Line: A common mode of speciation in oceanic islands is by anagenesis, wherein an immigrant arrives and through time transforms by mutation, recombination, and drift into a morphologically and genetically distinct species, with the new species accumulating a high level of genetic diversity.Drimys confertifolia shows a wide genetic variation within populations on both islands, and values of genetic diversity within populations are similar to those found within populations of the continental progenitor.The genetic results are compatible with the hypothesis of high levels of genetic variation accumulating within anagenetically derived species in oceanic islands, and with the concept of little or no geographical partitioning of this variation over the landscape.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Botánica, Universidad de Concepción, Casilla 160-C, Concepción, Chile.

ABSTRACT
A common mode of speciation in oceanic islands is by anagenesis, wherein an immigrant arrives and through time transforms by mutation, recombination, and drift into a morphologically and genetically distinct species, with the new species accumulating a high level of genetic diversity. We investigate speciation in Drimys confertifolia, endemic to the two major islands of the Juan Fernández Archipelago, Chile, to determine genetic consequences of anagenesis, to examine relationships among populations of D. confertifolia and the continental species D. winteri and D. andina, and to test probable migration routes between the major islands. Population genetic analyses were conducted using AFLPs and nuclear microsatellites of 421 individuals from 42 populations from the Juan Fernández islands and the continent. Drimys confertifolia shows a wide genetic variation within populations on both islands, and values of genetic diversity within populations are similar to those found within populations of the continental progenitor. The genetic results are compatible with the hypothesis of high levels of genetic variation accumulating within anagenetically derived species in oceanic islands, and with the concept of little or no geographical partitioning of this variation over the landscape. Analysis of the probability of migration within the archipelago confirms colonization from the older island, Robinson Crusoe, to the younger island Alejandro Selkirk.

Show MeSH
Related in: MedlinePlus