The study of pollen grains (the male reproductive cells of seed plants) is a vital part of our research activities. Microscopic differences, magnified up to 50,000 times, reveal a remarkable diversity of shape, size and structure. These differences are important diagnostic features which are used in plant identification and classification.
Why study pollen?
Pollen characters provide important information for plant taxonomy, evolution, pollination and plant breeding. The correct identification of pollen is important in the study of vegetation and climatic history, in forensic science, in the analysis of origins of honey and beeswax and in the alleviation of hayfever. Pollen research at the Royal Botanic Gardens, Kew is focused on the contribution of pollen characters to our understanding of the systematic and evolutionary relationships of various groups of flowering plants. Palynology staff are also frequently called upon for advice on a wide range of pollen-related topics including aerobiology, pollen storage and viability, bee poisoning, and bat forage.
Pollen of some large tropical families of economic importance is studied. In the Leguminosae (the bean family), for example, ultra-thin sections of pollen walls have provided clues to unexpected relationships between genera and species which have contributed to our understanding of the evolution of the family. Investigations are also focused on familes such as Burseraceae (rainforest and savanna trees, some of which yield important timbers) and Labiatae (the mint family). Examination of pollen apertures, and microsporogenesis in living members of the family, and the study of the fossil pollen record, assist our understanding of the evolution of the Arecaceae (the palm family).
Extensive studies of pollen apertures, microsporogenesis and tapetum in the monocotyledons and basal dicotyledons, have led to a better understanding of the evolution of these characters within the two groups. They have particularly contributed to our understanding of evolutionary relationships within monocots, especially within asparagoid lilies, Dioscoreaceae (yams and their allies) and Cyperaceae (sedges). Recent, and current work (2004>) is focussing on the crucial importance of pollen aperture evolution for the rapid radiation and success of the eudicotyledons.
The Palynology Unit, now part of the Micromorphology Group, was founded over thirty years ago. It is one of the world’s leading groups studying pollen in a systematic context. The Unit has links with universities and research institutes all over the world and the staff are involved in international research collaborations. Information is disseminated through research papers and books, and presentations at conferences and symposia
Scientific images of pollen grains
IIn order to study pollen in depth the Palynology Laboratory is equipped with a range of optical, scanning electron and transmission electron microscopes which are used to generate many thousands of images. With recent advances in digital technology, some of these microscopes are now equipped with digital imaging systems for electronic image capture. While the extensive collection of negatives of pollen images, accumulated from many years of active research, also continues to be an important resource.