Pollination ecology and plant-pollinator relationships are major topics in studies of floral evolution and plant speciation. The genetic basis of floral traits is a key factor in determining the evolutionary response to pollinator-mediated selection. Despite the important role of genetic background in evolutionary studies, it has rarely been incorporated into pollination studies. Extensive literature on the reciprocal effect of pollinators and floral traits on each other exists, yet only a few studies tested the effect of molecular genetic variation of pollination-relevant floral traits on pollinator behavior. Here, I review these studies and propose a framework to study pollinator-mediated selection in an evolutionary genetic context.
Two lines of research are used to study the genetic basis of pollination. The first approach connects candidate genes for floral traits with pollinator behavior. These genes can be modified, and the consequent reaction of the pollinators' behavior is then observed. The second approach uses indirect estimation of the genetic effect by constructing the genetic architecture that underlies floral characteristics, and quantifying its indirect effect on pollinator behavior and consequent measured fitness. This connection between pollinator behavior and genetics of floral traits, accompanied by the effect of pollinators on plant fitness, can be combined into a cascade of effects in a hierarchical statistical model that gives pollination ecology studies an evolutionary insight.