The Primula S locus: gene function and the maintenance and breakdown of heterostyly

Project Description

Pollination is important, ~70% of our food results directly from pollination as seeds, grains, fruits and berries. It is important to plants too for reproduction, which not only produces the next generation but creates variation upon which natural selection can act. This variation enables plants to adapt to changing environments and colonize new habitats. Most produce hermaphrodite flowers, but plants cannot move or actively choose a partner, instead they have evolved intriguing strategies to prevent self-pollination and promote cross-pollination. One of the most remarkable of these strategies is heterostyly, which uses insect pollinators (hetero=different; style=female structure). Charles Darwin observed that Primroses have two forms of flower, pin with a long style and short stamens, and thrum with a short style and longs stamens. These reciprocal positions facilitate pollen transfer by insect visitors between each flower type. A group of genes, known collectively as the S locus, controls development of the two forms of flower. A rich history of scientific research on Primroses by early botanists and geneticist made heterostyly an important textbook example of a plant breeding system. Our study will add to this work by using the latest research tools to explore how heterostyly arose, how it is controlled and why it occasionally goes wrong.