Morchella galilaea – Expanded phylogeography and relaxed seasonality of a globally distributed autumnal morel

Abstract

Morchella galilaea is unique among morels by its autumnal fruiting and a worldwide but disjunct distribution, strongly biased towards islands. The drivers of this reversed seasonality and transcontinental dispersal remain poorly understood. New records of M. galilaea from several islands of the Mediterranean, and from the Reunion Island in the Indian Ocean, all unveiled here, invited us to revisit and discuss the biogeography, phenology and ecology of this intriguing morel. Our ecological and molecular findings do not support recent anthropogenic introductions as causal for the tropism of M. galilaea for islands. Instead, we postulate a tentative model of evolution in which the paleotropical origins of the species may be responsible for the release of strict seasonality constraints inherited early during the genus’ evolutionary history.