Covariance of Floral and Vegetative Traits in Four Species of Ranunculaceae: A Comparison between Specialized and Generalized Pollination Systems

Abstract

Theory predicts that tighter correlation between floral traits and weaker relationship between floral and vegetative traits more likely occur in specialized flowers than generalized flowers, favoring by precise fit with pollinators. However, traits and trait correlations frequently vary under different environments. Through detecting spatiotemporal variation in phenotypic traits (floral organ size and vegetative size) and trait correlations in four Ranunculaceae species, we examined four predictions. Overall, our results supported these predictions to a certain degree. The mean coefficient of variation (CV) of floral traits in two specialized species (Delphinium kamaonense and Aconitum gymnandrum) was marginally significantly lower than that of another two generalized species (Trollius ranunculoides and Anemone obtusiloba). The two specialized species also showed marginally significantly smaller CV in floral traits than vegetative size across the two species. The absolute mean correlation between floral and vegetative traits, or that between floral traits in species with specialized flowers was not significantly lower, or higher than that in generalized plants, weakly supporting the predictions. Furthermore, we documented a large variation in trait correlations of four species among different seasons and populations. Study of covariance of floral and vegetative traits will benefit from the contrast of results obtained from generalized and specialized pollination systems.