What is special about Nymphaea thermarum?
What makes it a good model species:
Small size - N. thermaurm is the smallest member of the Nymphaeaceae (waterlily family). Hundreds of individuals can be grown on a greenhouse bench.
Easy to grow - unlike nearly every other waterlily, N. thermarum does not prefer to be completely submerged. Therefore only shallow tanks or tubs are needed. Quick life-cycle - it takes about 4-5 months for these plants to go from seed germination to flowering - an exceptionally short time compared to other members of the early-diverging flowering plant lineages. Small genome - At ~500 Mbp, the genome of N. thermarum is about 3 times the size of the Arabidopsis genome. Can self-fertilize or can out-cross - both modes of sexual reproduction are important for genetic experiments. Self-fertilization is important for creating and maintaining inbred lines, and out-crossing allows for controlled breeding of specific genotypes. Easy Propagation - hundreds of seeds can be produced in a single fruit, and seeds readily germinate |
Phylogenetic placement:
N. thermarum is a member of the subgenus Brachyceras, which is a pan-tropical clade that includes many of the day-blooming waterlilies. Nymphaea is the largest genus within the family Nympheaceae, which is in turn one of the three families that makes up the order Nymphaelaes.
Nymphaeales is one of the most ancient lineages of flowering plants (angiosperms). While angiosperms make up the vast majority of land plant species and form the basis for many of the ecosystems that human depend on, we know relatively little about the early evolution of this clade. By understanding how key angiosperm traits evolved, we can begin to make sense of the patterns of diversity we can observe across all of flowering plants. |
History of Nymphaea thermarum as a species:
As part of a floristic exploration of the Albertine Rift in Rwanda in 1987, Eberhard Fischer came across an unusual waterlily. It was remarkably small, had creamy white petals and an odd growth habit, and grew near a hot spring called Mashyuza. In 1988, it was described as a new species: Nymphaea thermarum (the species name highlights its unusual habitat preference). Plants were successfully grown in the Botanical Garden at Mainz University and at the University of Bonn, but they did not flower. Meanwhile, teams of botanists revisited the original sites where the species was discovered only to find that, by 2009, the original populations had disappeared when their habitats were altered for use by local people.
With no known plants in the wild, it became very important to figure out how to get these little waterlilies to flower; since they do not readily propagate vegetatively, seeds are needed to create large numbers of new plants. Plants were given to The Royal Botanical Gardens at Kew to establish a project for the conservation and reintroduction of the species, in conjunction with the Rwanda Development Board. At Kew, the care and task of getting the plants the flower was taken over by Carlos Magdalena Rodriguez, a resident horticultural expert. By using clues about the conditions at the original collection sites, Carlos was able to figure out that the plants, despite being waterlilies, do not like being completely submerged in water. Keeping the water level about equal with the tops of the plants and the soil leads to the ready production of flowers. Since hundreds of seeds can be produced within a single fruit and a single plant will continually produce flowers as long as it has enough nutrients, large populations can be created and maintained! For more about the history of this species, read these articles: Carlos Magdalena Rodriguez explains how he figured out how to get N. thermarum to flower: http://www.victoria-adventure.org/more_than_links_images/carlos/page1.html A paper that describes the history and growth: Fischer E, Magdalena-Rodriguez C. 2010. Nymphaea thermarum (Nymphaeaceae). Curtis Botanical Magazine 27: 318–327. Link to paper. |