The effect of within-genet and between-genet competition on sexual reproduction and vegetative spread in Potentilla anserina ssp. egedii
Pirjo Rautiainen (fax +35 8085531061; e-mail email@example.com).
- 1Patterns of biomass allocation to sexual and vegetative reproduction were examined in a perennial stoloniferous clonal plant, Potentilla anserina (L.) Rydb. ssp. egedii (Wormsk.) Hiitonen, in relation to intraspecific competition between monoclonal and multiclonal ramets.
- 2We predicted that a lack of competition would generate allocation to rapid, short-distance spread (vegetative propagation), while the presence of competition would increase allocation to long-distance dispersal (sexual reproduction), and that the allocation shift would be more pronounced where the competing ramets were related.
- 3P. anserina ramets were grown in a glasshouse in small pots, either alone (no competition) or with a size-matched ramet that originated from the same clone (within-genet competition) or a different one (between-genet competition).
- 4Competition suppressed both growth and reproduction, but there was no treatment response in relative investment at the level of a whole genet, although both mother ramets and their daughters showed clear effects when analysed separately.
- 5When experiencing competition, the mother ramet allocated relatively more to flowers, whereas allocation to vegetative growth was more intense when competition was absent. Allocation patterns were independent of the relatedness of competitors.
- 6The results imply that P. anserina can modify the allocation of resources to different life-history traits according to competitive stress. Such flexibility is likely to reflect a shift in the optimal allocation strategy during the life cycle of a plant with a guerilla growth form with rapid exploitation of free space in a new patch by vegetative spread favoured. When spread becomes limited by competition, long-distance dispersal in space (seeds) or time (persistence) becomes beneficial.