INVESTIGADORES
COCUCCI Andrea Aristides
congresos y reuniones científicas
Título:
Multiple periglacial refugia and post-glacial colonization of the Andes in the Patagonian herb Calceolaria polyrhiza.
Autor/es:
COSACOV, A.; SÉRSIC, A. N.; SOSA, V.; JOHNSON, L.; COCUCCI, A. A.
Lugar:
Bariloche, Argentina
Reunión:
Simposio; VI Southern Connection Congress; 2010
Resumen:
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For
Calceolaria polyrhiza we aimed to determine whether phylogeographic patterns
corresponded to in situ Pleistocene survival or to glacial retreat and
postglacial expansion and, to reveal putative glacial refugia and post-glacial
colonization routes. Haplotypes (27) of the trnH-psbA- intergenic cpDNA spacer
were obtained from 68 populations (590 indiv.) covering the entire range of
this widely distributed Patagonian endemic herb occurring both in the temperate
forests and arid steppe. Three phylogeographic breaks revealed four major
lineages: two high Andean split first during the late Miocene, and two
Patagonian, ca 4 Ma BP coincident with the steppe establishment. The Patagonian
groups exhibited diversification, rapid population expansion and colonization
of the Andes flanks to the end of the
Pleistocene. Populations in formerly ice-covered locations are monomorphic for
the four most abundant haplotypes, suggesting recent independent colonizations
by zonal steppe lineages. Highest diversity spots were found along a N-S transect
congruent with the GPG ice-sheet limits. Past climate fluctuations influenced on
diversification, distribution and demography of this plant. A scenario of
multiple periglacial Pleistocene refugia and subsequent multiple recolonization
routes, from east Patagonia to the Andean
flanks, is proposed. The phylogeographic structure also preserves imprints of
older phenomena, suggesting multiple and complex processes may moulded
biodiversity in Patagonia.