International research reveals that the European mushroom Amanita phalloides is capable of reproducing without a mate in California

International research revealed that the European mushroom Amanita phalloides is capable of reproducing without a mate in California. Susana C. Gonçalves, a researcher from the Centre for Functional Ecology (CFE) from the Faculty of Sciences and Technology from the University of Coimbra (FCTUC), is one of the authors of the scientific paper “Invasive Californian death caps develop mushrooms unisexually and bisexually”, published in the Nature Communications journal.

The deadly mushroom from the Amanita phalloides species originates from Europe, however, it was inadvertently introduced in the United States of America (USA), where it has expanded, mainly on the West Coast. This research uncovers this European mushroom’s strange sexual life in California and helps to explain the fast dissemination of the fungus.

This research made it possible to “identify that, in California, the fungus is capable of reproducing without a mate, by self-fertilization, an unusual type of sexual reproduction in fungi that was rarely observed outside of the laboratory”, reveals Anne Pringle from the University of Wisconsin-Madison, USA, coordinator and senior author of the study, explaining that “this species normally reproduces bisexually: the mycelia of two different compatible mating specimens fuse and generate mushrooms that contain DNA from both specimens”.

This type of reproduction still happens in Europe. The research team sequenced European mushrooms’ DNA, including several Portuguese populations, and discovered that these contained two sets of genetic material, one from each parent. However, in California, where this species’ mushrooms were observed for the first time in the early 20^th century, the fungus appears to be doing something quite different.

“DNA from some of the mushrooms from California contained only a set of genetic material, suggesting that each one had originated from a single specimen. It is not very clear how this is done”, observe the authors of this research, proposing that “Amanita phalloides somehow bypasses the genetic controls that guarantee that mushrooms can only reproduce after two specimens have fused together”.

“The capacity to self-fertilize can be an advantage when the species reaches a new habitat where there aren’t any compatible mates”, points out Susana C. Gonçalves. Therefore, the authors suggest that unisexuality can help justify the fast dissemination of this species throughout the West Coast of the United States.

“The next step is to find out if other invasive species of fungi are using similar strategies in nature”; concludes.

The scientific paper “Invasive Californian death caps develop mushrooms unisexually and bisexually” can be found HERE.

(Press release written in portuguese by Sara Machado, FCTUC)