IANIGLA   20881
INSTITUTO ARGENTINO DE NIVOLOGIA, GLACIOLOGIA Y CIENCIAS AMBIENTALES
Unidad Ejecutora - UE
artículos
Título:
Extensive pollen flow in a natural fragmented population of Patagonian cypress Austrocedrus chilensis
Autor/es:
COLABELLA, F; GALLO, L A; MORENO, C; MARCHELLI, P.
Revista:
TREE GENETICS & GENOMES
Editorial:
SPRINGER HEIDELBERG
Referencias:
Lugar: HEIDELBERG; Año: 2014 vol. 10 p. 1519 - 1529
ISSN:
1614-2942
Resumen:
Habitat fragmentation might significantly affect
mating and pollen dispersal patterns in plant populations,
contributing to the decline of remnant populations. However,
wind-pollinated species are able to disperse pollen at longer
distances after opening of the canopy. Our objectives were to
characterize the mating system parameters and to estimate the
average distance of effective pollen dispersal in the windpollinated
conifer Austrocedrus chilensis. We sampled 19
?mother trees,? 200 progeny, and 81 additional adults (both
male and female), in a fragmented population at the
Argentinean Patagonian steppe. We registered the spatial positions
of individuals and genotyped all samples with five
microsatellite markers. We found a high genetic diversity, a
moderated rate of biparental inbreeding (tm−ts=0.105), and a
complete absence of correlated paternity (rp=−0.015). The
effective number of pollen donors contributing to a single
mother (Nep) was 13.9. Applying TWOGENER, we estimated
a low but significant differentiation among the inferred pollen
pools (ΦFT=0.036, p=0.001) and a very large average pollen
dispersal distance (d=1,032.3 m). The leptokurtic distribution
(b=0.18) presumes a potential for even larger dispersal distances.
The high genetic diversity, the mating patterns, and the
extensive pollen dispersal presume that habitat fragmentation
did not have a negative impact on pollen movement in this
population of A. chilensis. Genetic connectivity among
fragmented populations scattered in the Patagonian region is
possible, and we stress the need of management policies at the
landscape level.