Morphology and development of floral features recognised by pollinators

The diversity of angiosperm flowers is astounding. The conventional explanation for this diversity is that it represents the great variety of ways in which flowers have adapted to attract an even greater diversity of animal pollinators. Many animal behaviourists are therefore interested in how changes in floral morphology affect pollinator behaviour. The establishment of well-characterised model plant species has greatly furthered our understanding of how floral morphology is generated and varied. Many of these model species are pollinated by animals and attract their pollinators through the production of colour, shape, scent, size and rewards. An understanding of the developmental plasticity of floral morphology, and the constraints upon it, should inform research into animal responses to flowers. The use of genetically characterised model species, and the isogenic and near-isogenic lines available in them, will allow dissection of the different components of floral attraction and reward in natural systems. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. Handling editor: Heikki Hokkanen     

Floral biology of Echinopsis chiloensis ssp. chiloensis (Cactaceae): Evidence for a mixed pollination syndrome

In this study the flower biology of Echinopsis chiloensis ssp. chiloensis, a columnar cactus occurring in Central Chile, is investigated, in particular its pollination syndrome, its visitors, their frequencies and behaviors and their pollination efficiencies. As statements on floral anthesis of this species are contradictory, this study also intended to elucidate both its beginning and duration. A pollinator exclusion study of a total of 162 flowers from 12 plants was conducted at one of the two study sites. Fruit and seed production as well as seed viability were documented to evaluate pollinator efficiencies.     

Progamic phase and fertilization inGasteria verrucosa (Mill.) H. Duval: pollination signals

A summary is given of the pollen tube pathway, the interactions during the progamic phase and the incompatibility system ofGasteria. Pollen coating substances stimulate pollen tube ovular penetration and fruit set in cases of cross-pollination. Pollen coating substances also stimulate the water supply of the pistil which completes the pollen tube pathway. These two types of signals are related to recognition reactions, as well as to the activation of the pistil. Because the pollen coating substance is of sporophytic origin, the incompatibility system type is discussed.