The size and pattern of flowers like hibiscus play a significant role in attracting pollinating bees. A study conducted by researchers at the University of Cambridge’s Sainsbury Laboratory found that bees prefer larger bullseyes on flowers and fly faster between flowers with larger bullseyes. These patterns guide insects to the centre of the flower, where nectar and pollen are located, enhancing pollination success.
Using a hibiscus plant as a model, researchers compared closely related plants with different sized bullseye patterns that all had the same flower size. They discovered that a pre-pattern is established early in the flower’s formation, dictating the size and shape of the bullseye long before it becomes visible. Plants have the ability to control and modify these patterns using various mechanisms, potentially impacting plant evolution and their ability to attract different species of pollinators.
Lead author Dr Lucie Riglet studied petal development in hibiscus flowers with varying bullseye patterns and found that the pre-pattern begins as a small, crescent-shaped region on tiny petals less than 0.2mm in size. This pre-pattern is crucial in determining the boundary of the bullseye. Researchers discovered that hibiscus can adjust bullseye dimensions very early during development or modify growth later by changing cell expansion or division.
Dr Riglet conducted an experiment with artificial flower discs mimicking three different bullseye dimensions to compare the attractiveness of the patterns to pollinators. Bees showed a preference for medium and larger bullseyes over smaller ones and were quicker to visit flowers with larger bullseyes. This suggests that the pre-patterning strategies observed in the hibiscus flowers could have deep evolutionary roots and influence the diversity of flower patterns across different species.
The research not only enhances our understanding of plant biology but also highlights the intricate connections between plants and their environment. The precise designs found in nature can play a crucial role in the survival and evolution of species, as seen in the case of the critically endangered H. richardsonii with the smallest bullseye and the widely distributed H. trionum with a larger bullseye. Further research is needed to determine how bullseye size impacts a plant’s reproductive success and ability to attract pollinators.
Dr Edwige Moyroud’s team is focusing on identifying the signals responsible for generating early patterns in plants and exploring whether similar mechanisms are at play in other plant organs. By understanding how nature generates biodiversity through different patterning methods, researchers hope to gain insights into the diversity of flower patterns and their impact on plant evolution. This research sheds light on the significance of pre-patterning strategies in plants and their potential role in shaping the diversity of floral patterns across various plant species.