The Mushroom “Tree of Life”

Genetic material from fungi collections at Purdue University in the United States and at the Royal Botanic Gardens, Kew, in the UK helped a team of researchers resolve the mushroom "tree of life," a map of the relationships between and among key mushroom species and their evolutionary history that scientists have struggled to piece together for more than 200 years. The group used DNA from frozen, heat-dried and freeze-dried specimens to analyze a dataset of 39 genomes representing most of the known families in Agaricales, the order that includes some of the most familiar kinds of mushrooms, including cultivated edible mushrooms, magic mushrooms, and the deadly destroying angel (image). High-throughput sequencing technology allowed the scientists to define seven new suborders and the "trunk" of the Agaricales tree, providing a framework for testing hypotheses of the evolution of mushrooms. "Mycology really is one of the last frontiers in biology," said Dr. Catherine Aime, Associate Professor of Mycology at Purdue. "We know there are 6 to 20 times more species of fungi than plants, but we don't really know much about them. People have tried to figure out how mushrooms are related since the time of Linnaeus. It's gratifying to finally solve this mystery." Fungi are essential to the health of ecosystems, plants, and animals. They decompose fallen wood and other organic matter, breaking down material and freeing up nutrients for other organisms. Most land plants rely on beneficial fungi to deliver water and other nutrients, and the gut fungi of ruminants such as cows play a vital role in digestion. Most humans also host fungi, which help maintain the balance of our natural flora. But despite their importance and rich diversity, comparatively little is known about fungi. Many species have "cryptic and unpredictable life histories," Dr.