杏吧原创

A newly identified species of water lily is also the largest of its kind, with lily pads up to 3.2 metres wide and flowers that are each larger than a human head.

鈥淭he lily pads could definitely take the weight of a young child,鈥� says at Kew Gardens in the UK,聽a member of the聽research team. In theory, the massive leaves can support the weight of an adult of about 80 kilograms. 鈥淸But] I think you鈥檇 have to put some kind of support in it to distribute their weight on the lily pad,鈥� says Przelomska. 鈥淭hough we鈥檝e not tested it!鈥�

The new species, named Victoria boliviana, is just the third known species of giant water lily.

In 2016, Bolivian institutions Santa Cruz de La Sierra Botanic Garden and La Rinconada Gardens donated a collection of giant water lily seeds to Kew Gardens. As Carlos Magdalena 鈥� a horticulturalist at Kew and member of the research team 鈥� germinated and grew the seeds he could see they were different from the two known species of water lily. In 2019, he visited Bolivia to see the water lilies growing in the wild.

V. boliviana grows in freshwater rivers, floodplains and ponds in north-eastern Bolivia. Although it is unclear exactly why it evolved to be so big, previous studies suggest that the large size of water lilies may help them compete with other plants for sunlight.

鈥淭he biodiversity in the tropics is so high, so when an aquatic area opens up 鈥� for example, because the rivers suddenly become larger due to a flood 鈥� the water lilies can thrive there because they grow really quickly and capture so much of the sunlight, and outcompete other plants,鈥� says Przelomska.

As part of the new work, Przelomska and her colleague, , co-led an analysis of the genome of聽V. boliviana. They found it was slightly bigger than that of water lily species,聽Victoria cruziana, but smaller than that of Victoria amazonica. It contains over 4 billion base pairs.

鈥淕enerally, a larger plant wouldn鈥檛 necessarily have a larger genome, but the biggest water lilies happen to have the biggest [lily] genomes and we鈥檇 like to understand why,鈥� says Przelomska.

Further genetic analysis revealed that the common ancestor of V. cruziana and V. boliviana split from V. amazonica about 5 million years ago, while the common ancestor of V. cruziana and V. boliviana existed about 1 million years ago.

The team also found that V. boliviana seems to be at greater risk of extinction than the other two species, due to the smaller geographical range over which it lives. All three species are under increased threat as deforestation in the Amazon continues.

鈥淟ike the other species, V. bolivana is at threat because the environment has been degraded year by year,鈥� says Przelomska.

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