2 research outputs found
Should we sync? Seascape-level genetic and ecological factors determine seagrass flowering patterns
3 figuras, 2 tablas1. Spatial and temporal heterogeneity in flowering occur in many plant species with abiotic
pollination and may confer fitness advantages through mechanisms such as predator
satiation or pollination efficiency. Environmental factors such as light quality or quantity and
temperature play an important role in inducing synchronisation on wide geographic scales.
On a smaller geographic scale, external factors such as resource availability and herbivory
are theorised to trigger flowering, while genetic factors may also play an important role.
2. In this study, we assessed the importance of ecological and genetic factors in shaping
seascape-level spatial heterogeneity in flowering of the seagrass Posidonia oceanica. By
investigating spatially close sites (<20 km) with similar seascape configurations and depth,
we assume that major environmental drivers (temperature and light) were equivalent.
3. We assessed four ecological factors (productivity, leaf nitrogen and carbon content and
herbivory) and three genetic factors (heterozygosity, relatedness and clonality) to assess
three hypotheses for synchronised flowering in P. oceanica: (1) clone synchronisation
(internal clock hypothesis), (2) variation in nutrient availability, potentially caused by spatial
heterogeneity in herbivory rates or nutrient translocation via clonal integration (resource
budget hypothesis) or (3) kin selection and sibling synchronisation. 4. Internal relatedness and heterozygosity had a significant positive effect on the abundance of
flowers. Moreover, productivity and genotypic richness (clonality) were negatively
associated with flower density, although at a lower level of significance. In addition we
found that clones were almost exclusively shared among mass-flowering patches and
patches without mass-flowering, respectively.
5. Synthesis. The results shed new light on seagrass flowering patterns and on the mechanisms
of flower synchronisation at the patch level within a wider spatial scale. We found support
for the kin selection hypothesis and indirect evidence for the resource budget hypothesis.
Thus a combination of mainly genetic but also ecological factors causes the observed
heterogeneous flowering patterns in Posidonia oceanica seascapes. In addition, we found a
strong positive relationship between the number of flowers and heterozygosity, adding
evidence to the controversial association between heterozygosity and fitness when a limited
number of loci are used. To our knowledge, this study is the first to link both ecological and
genetic factors with flower abundance in a species with a presumed masting strategy.This
research was partially supported by the European Community’s 7th Framework Programme
(FP7/2007–2013) CoCoNet, the MIUR Italian Flagship project RITMARE, the Spanish Ministry of
Science and Innovation (CTM2010-22273-C02-02) and the Spanish National Research Council
(PIE201330EO62). M.J. is supported by a SZN PhD fellowship via the Open University and the Spanish
Ministry of Education supported J.P. (scholarship AP2008- 01601).Peer reviewe