Although it was present all the time, beneath a thin layer of ocean off Australia’s coast, it was thought to have been a large posidonia field with thousands of individuals. A genetic study that was done to determine how many species of flora were present in the 200-km2 area surprised scientists. Although it was fragmented, it was a single, very long specimen of ‘Posidonia Australis’. Researchers at Flinders University and the University of Western Australia (UA) discovered that the largest known plant in the world occupies an area comparable to 28,000 football pitches.
Jane Edgeloe, an Australian student, was able to determine the genetic richness and size of the huge, green seagrass found in Shark Bay. After ten samples from different areas of the aquatic grass had been collected, 18,000 genetic markers were added to them. The investigators expected to find multiple fingerprints. But, there was only one! Edgeloe exclaimed in a UWA statement. “That’s all, it’s just a plant that spans more than 180km, making this the largest plant known on Earth.”
It would be not only the largest living plant, but also one of the most durable. According to the same results, scientists have calculated that the plant is approximately 4,500 years old. Biological Sciences. It also showed that it has twice the normal number of chromosomes. This allows it to survive in extreme conditions like high temperatures and high levels of salt. They are often sterile but they can still grow, as was the case with the Posidonia.
Scientists find the most important aspect of the discovery of “a single polyploid-clone”, which would have confirmed that the plant is one. They explain this in an article published June 1. Polyploidy is a common trait in flowering plants and “has the potential for organisms to outgrow diploid parents.” This explains why the specimen is so large: “The duplication of the entire genome through polyploidy combined with clonality may have allowed the plant to adapt to new environments and new habitats that became increasingly stressful for their parents.”
This genetic quality, which duplicates the chromosomes of chromosomes is considered an “evolutionary death end” that can “create beasts”, as has been proven in terrestrial species. It is now well-known that this gene also plays a part in Posidonia meadows. These “habit seacoasts or estuaries around the globe, except Antarctica”, and are often rich in genetic diversity. This almost-solitary Posidonia, which has at least one neighbour of another species, “recolonized” the continental shelf in the case of the Australian Seas.
Researchers say that Shark Bay’s giant Posidonia is clinging to large areas sandy sediments, which are protected from the ocean waves. “The environment is perfect for vegetative expansion and clonal growth.” It has been thriving for millennia because of its extreme conditions, including the shallow coast banks and thresholds that are marked by natural carbon sequestration.
The size record for Posidonia oceanica was 15km long and held the ancient diploid clone ‘Posidonia oceanica. The article concludes that Posidonia meadows can “continue almost indefinitely if they are left undisturbed because they rely more on vegetative expansion of horizontal rhizomes than sexual reproduction.”
