Using the 'green ashes' to study evolution
The Eucalyptus species known as the ‘green ashes’ are a group of closely related eucalypts and include tall trees, medium trees and mallees (multi-stemmed plants that are usually less than 10 metres tall).
By comparing the highly genetically different group of ‘green ashes’ to the other species of Eucalyptus with more gene mixing, the team discovered that they were documenting the process through which new species of Eucalyptus form.
Technical Officer Biodiversity Genomics at the Royal Botanic Garden Sydney (and lead author of this recent research), Dr Susan Rutherford, said the green ashes are unique because they can grow in a range of habitats.
“The green ashes are found in fertile and nutrient poor soils from the coast to cold highland environments. The fact they have evolved to be so diverse and grow in different habitats makes them a perfect group for studying evolutionary processes,” Dr Rutherford said.
“To study their DNA and evolution, we needed to collect leaf material, so we embarked on an expedition to many beautiful and iconic places, such as Govetts Leap, Fitzroy Falls and Pulpit Rock.
“The Blue Mountains is a hot spot for Eucalyptus diversity and the area was declared World Heritage partly because it is home to about 100 different species,” said Dr Rutherford.
Upon their return, the collected leaf material was given to the laboratory at the Royal Botanic Garden Sydney, where DNA was extracted from six green ash species and sent to Diversity Arrays Technology (DArT) Ltd in Canberra for analysis.