IMBIV   05474
INSTITUTO MULTIDISCIPLINARIO DE BIOLOGIA VEGETAL
Unidad Ejecutora - UE
artículos
Título:
Mating system, outcrossing distance effects and pollen availability in the wind-pollinated treeline species Polylepis australis BITT. (Rosaceae).
Autor/es:
SELTMANN, P.; COCUCCI A. A.; RENISON, D.; CIERJACKS, A.; HENSEN, I.
Revista:
BASIC AND APPLIED ECOLOGY
Referencias:
Año: 2008 p. 1 - 9
Resumen:
Fragmentation may negatively affect plant fitness
through pollen limitation and increased levels of inbreeding. Effects of
fragmentation may vary with regard to life form and breeding system, and few
studies exist for wind-pollinated trees. We examined the effects of
hand-selfing, varying outcrossing distances and pollen addition on seed mass
and germination rate of Polylepis australis BITT. (Rosaceae), a wind-pollinated
treeline species endemic to Argentina. We also investigated pollen germination
on the stigma and pollen tube growth to determine compatibility resulting from
selfing and outcrossing. Selfing reduced seed germination rates with
significant differences between open pollination and outcrosses at 30 km. In addition, we found
a tendency for pollen germination and pollen tube growth to decrease following
selfing. Between-fragment crosses resulted in a trend of higher reproductive
output than within-fragment crosses, whereas values were similar between open
pollination and between-fragment crosses. Pollen addition did not increase
reproductive success neither in small nor in larger fragments. Our results
suggest that highly isolated P. australis forests have a potential for
inbreeding depression through selfing and within-fragment crosses. However, the
results also indicate that pollen flow between P. australis forest fragments is
still effective at the current fragmentation level, counteracting negative
effects on seed quality resulting from reprodu