Trade-offs between sexual and clonal reproduction in an aquatic plant: experimental manipulations vs. phenotypic correlations.
That trade-offs result from the allocation of limited resources is a central concept of life history evolution. We quantified trade-offs between sexual and clonal reproduction in the aquatic plant, Butomus umbellatus, by experimentally manipulating sexual investment in two distinct nutrient environments. Increasing seed production caused a significant but nonlinear trade-off. Pollinating half of all flowers strongly reduced clonal bulbil production, but pollinating the remaining flowers did not cause any further trade-off. Trade-offs were not stronger under low nutrient conditions that clearly limited plant growth. Experimentally induced trade-offs were not reflected in negative phenotypic correlations between sexual and clonal allocation among plants within eight populations grown in a uniform greenhouse environment. Diminishing effects of increased sexual allocation plus a lack of accord between experimental manipulations and phenotypic correlations suggest that trade-offs between sexual and clonal reproduction are unlikely to constrain the evolution of reproductive strategy in this species.
Thompson
F L
FL
Department of Biology, Queen's University, Kingston, Ontario, K7L 3N6, Canada.
Eckert
C G
CG
D000704:Analysis of Variance; D005075:Biological Evolution; D018533:Biomass; D004777:Environment; D005618:Fresh Water; D019684:Magnoliopsida / Q000235:genetics / Q000502:physiology*; D009864:Ontario; D010641:Phenotype; D012098:Reproduction / Q000502:physiology; D012639:Seeds / Q000502:physiology*