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Relationships and genetic consequences of contrasting modes of speciation among endemic species of Robinsonia (Asteraceae, Senecioneae) of the Juan Fernández Archipelago, Chile, based on AFLP s and SSR s
Author(s) -
Takayama Koji,
LópezSepúlveda Patricio,
Greimler Josef,
Crawford Daniel J.,
Peñailillo Patricio,
Baeza Marcelo,
Ruiz Eduardo,
Kohl Gudrun,
Tremetsberger Karin,
Gatica Alejandro,
Letelier Luis,
Novoa Patricio,
Novak Johannes,
Stuessy Tod F.
Publication year - 2015
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.13000
Subject(s) - biology , senecioneae , amplified fragment length polymorphism , cladogenesis , genetic variation , evolutionary biology , population , genetic structure , isolation by distance , subgenus , archipelago , endemism , phylogenetic tree , genetic variability , senecio , genus , botany , ecology , genetics , genetic diversity , clade , gene , genotype , demography , sociology
Summary This study analyses and compares the genetic signatures of anagenetic and cladogenetic speciation in six species of the genus Robinsonia (Asteraceae, Senecioneae), endemic to the Juan Fernández Islands, Chile. Population genetic structure was analyzed by amplified fragment length polymorphism ( AFLP ) and microsatellite (simple sequence repeat, SSR ) markers from 286 and 320 individuals, respectively, in 28 populations. Each species is genetically distinct. Previous hypotheses of classification among these species into subgenera and sections, via morphological, phytochemical, isozymic and internal transcribed spacer ( ITS ) data, have been confirmed, except that R. saxatilis appears to be related to R. gayana rather than R. evenia . Analysis of phylogenetic results and biogeographic context suggests that five of these species have originated by cladogenesis and adaptive radiation on the older Robinson Crusoe Island. The sixth species, R. masafuerae , restricted to the younger Alejandro Selkirk Island, is closely related to and an anagenetic derivative of R. evenia from Robinson Crusoe. Microsatellite and AFLP data reveal considerable genetic variation among the cladogenetically derived species of Robinsonia , but within each the genetic variation is lower, highlighting presumptive genetic isolation and rapid radiation. The anagenetically derived R. masafuerae harbors a level of genetic variation similar to that of its progenitor, R. evenia . This is the first direct comparison of the genetic consequences of anagenetic and cladogenetic speciation in plants of an oceanic archipelago.