A Comparative Study Of Phenotypic Selection On Pedicularis Corolla

Corolla diversity is the outstanding characteristic of plant adaptive radiation. Therefore, researches on corolla diversity pattern are helpful to understanding the processes of angiosperm speciation deeply. In this study, Pedicularis were selected as materials. Ecological factors (such as pollinators and predators), which may influence phenotypic traits of Pedicularis, were mearsured and quantitatively analysed. So we can explore the pattern of Pedicularis diversity.First, we analysed three main ecology factors:pollinators, predators and abiotic factors. Pollinators can lead floral trait divergence directly in some cases. The main pollinators are two species of Bumbus:Bumbus richardsi and B. festivus. The main predators are flies and bees, which perefer certain Pedicularis species.Second, we set 11 plots to observe pollinator visit frequency quantitily on three corolla types of Pedicularis. Bumblebees visited high-frequency species prioritily and more frequently when pollinators were rare and flowers were adequate; bumblebees visit corolla with nectar more than without nectar when no different frequency.Thirdly, investigation of the predators’ behavior showed that the species with pink corolla suffered more serious damage than other types. Furthermore, pink corolla species had higher frequency in the community. So predator preferrence was colour discrimination or frequency dependant.Fourth, in the analysis of phenotypic selection, phenology was one important character which suffers selective forces. Other traits about beak were liable to be selected, which may be fit for smaller size bumblebee selective pressure. P. longiflora and P. cephalantha suffer more selective forces.