Special Issue on The Ecology and Evolution of Pollen Performance
After pollination, pollen must hydrate, germinate, develop sperm, and grow a pollen tube to reach an ovule and egg. These performance functions are constrained to occur between stigma receptivity and egg maturity. Often, pollen must also compete with other pollen for access to eggs, as shown here on the stigma of Hibiscus moscheutos. Pollen tube growth rates in Hibiscusare 10 to 100 times faster than those of the majority of other angiosperms, a pattern that may have evolved via a combination of the effects of pollen competition and the elongation of theHibiscus style. Yet Hibiscus pollen tubes display a relatively expensive pattern of growth, suggesting stylar resources are not strongly limiting their growth. These and many other topics are explored in this special issue, "The Ecology and Evolution of Pollen Performance," which brings together new and interesting ideas about the many forces that affect pollen functional biology. Topics range from mechanistic aspects of pollen germination and growth, to ecological effects on growth, to the consequences of natural and sexual selection on performance traits.
Image credit: Jacob A. Edwards.