Landing lights for bumblebees
12 October 2010
Gardeners could help maintain bumblebee populations by growing plants with red flowers or flowers with stripes along the veins, according to field observations of the common snapdragon, Antirrhinum majus, at the John Innes Centre in the UK.
Snapdragons in glasshouse
Bees are important pollinators of crops as well as the plants in our gardens. The John Innes Centre, an institute of the BBSRC, is committed to research that can benefit agriculture and the environment.
"Stripes following the veins of flowers are one of the most common floral pigmentation patterns so we thought there must be some advantage for pollination," said Professor Cathie Martin from JIC.
Nuffield Bursary students spent successive summers observing the foraging patterns of bumblebees on snapdragon plants grown on a plot near Norwich. The students compared the number of visits by bumblebees to various cultivars of the common snapdragon and the number of flowers visited per plant. Red flowers and those with venation patterning were visited significantly more frequently than white or pink. More flowers were visited per plant too.
"Stripes provide a visual guide for pollinators, directing them to the central landing platform and the entrance to the flower where the nectar and pollen can be found," said Professor Martin.
Bumblebee on snapdragon
"We examined the origin of this trait and found that it has been retained through snapdragon ancestry. The selection pressure for this trait is only relaxed when full red pigmentation evolves in a species."
Bumblebees are the main pollinators for snapdragon because the weight of the bee is needed to open the closed flower. Pollinators learn and memorize floral signals, such as flower shape, scent, colour and patterns of pigmentation. They return to flowers from which they have previously found food. Simple changes due to single gene changes can have dramatic effects on which pollinators visit and how often.
Collaborators on the project from New Zealand also analysed how the stripy patterns are formed along the veins of the common snapdragon. They showed that two signals interact to create the stripes.
"Complex colour patterns such as spots and stripes are common in nature but the way they are formed is poorly understood," said author Dr Kathy Schwinn from the New Zealand Institute for Plant & Food Research.
"We found that one signal comes from the veins of the petals and one from the skin of the petals, the epidermis. Where these signals intersect, the production of red anthocyanin pigments is induced."
Professor Douglas Kell, Chief Executive of BBSRC, which part-funded this research through strategic funding to JIC, said: "Pollinator insects, such as honeybees, have a highly significant role in agriculture and any reduction in numbers is economically damaging and risks our food security. Much of the food on our plates is reliant on insect pollination. BBSRC is investing in research to understand how we can arrest pollinator decline and this study shows how horticulturalists and gardeners can encourage bumblebee populations."
Notes to Editors
Reference: The molecular basis for venation patterning of pigmentation and its effect on pollinator attraction in flowers of Antirrhinum, Yongjin Shang, Julien Venail, Steve Mackay, Paul Bailey, Kathy Schwinn, Paula Jameson, Cathie Martin, Kevin Davies. New Phytologist, October 2010, doi: 10.1111/j.1469-8137.2010.03498.x
The John Innes Centre, www.jic.ac.uk, is an independent, world-leading research centre in plant and microbial sciences with over 800 staff. JIC is based on Norwich Research Park and carries out high quality fundamental, strategic and applied research to understand how plants and microbes work at the molecular, cellular and genetic levels. The JIC also trains scientists and students, collaborates with many other research laboratories and communicates its science to end-users and the general public. The JIC is grant-aided by the Biotechnology and Biological Sciences Research Council.
About Plant & Food Research
Plant & Food Research is a New Zealand based science company focused on generating knowledge that ensures sustainable growth in the plant and marine-based food industries. With over 900 staff based at sites across New Zealand and globally, Plant & Food Research provides research and development that adds value to fruit, vegetable, crop and food products. Their science in key areas - including elite cultivar development, sustainable production systems and bioprotection - supports the production of high quality produce that earns a premium in international markets. Their research in food science and the consumer drives the design and development of new and novel functional foods that offer benefits to human health and wellbeing.
About the Nuffield Foundation
Nuffield Foundation science bursaries for schools and colleges offer up to 1000 bursaries a year, for students to work alongside practising scientists, technologists, engineers and mathematicians. Projects take place during the summer holidays, giving students an insight into the world of scientific research and development. www.nuffieldfoundation.org
BBSRC is the UK funding agency for research in the life sciences. Sponsored by Government, BBSRC annually invests around £470M in a wide range of research that makes a significant contribution to the quality of life in the UK and beyond and supports a number of important industrial stakeholders, including the agriculture, food, chemical, healthcare and pharmaceutical sectors.
BBSRC provides institute strategic research grants to the following:
- The Babraham Institute
- Institute for Animal Health
- Institute of Biological, Environmental and Rural Sciences (Aberystwyth University)
- Institute of Food Research
- John Innes Centre
- The Genome Analysis Centre
- The Roslin Institute (University of Edinburgh)
- Rothamsted Research
The Institutes conduct long-term, mission-oriented research using specialist facilities. They have strong interactions with industry, Government departments and other end-users of their research.