The Gondwanan connection – Southern temperate Amanita lineages and the description of the first sequestrate species from the Americas

Abstract

Amanita is a diverse and cosmopolitan genus of ectomycorrhizal fungi. We describe Amanita nouhrae sp. nov., a new hypogeous ('truffle-like') species associated with Nothofagus antarctica in northern Patagonia. This constitutes the first report of a sequestrate Amanita from the Americas. Thick-walled basidiospores ornamented on the interior spore wall ('crassospores') were observed consistently in A. nouhrae and its sister epigeous taxon Amanita morenoi, a rarely collected but apparently common species from northern Patagonia that has sometimes been misidentified as the Australian taxon Amanita umbrinella. Nuclear 18S and 28S ribosomal DNA and mitochondrial 16S and 26S DNA placed these two species in a southern temperate clade within subgenus Amanita, together with other South American and Australian species. Based on a dated genus-level phylogeny, we estimate that the southern temperate clade may have originated near the Eocene/Oligocene boundary (ca. 35 Ma ± 10 Ma). This date suggests a broadly distributed ancestor in the Southern Hemisphere, which probably diversified as a result of continental drift, as well as the initiation of the Antarctic glaciation. By comparison, we show that this clade follows an exceptional biogeographic pattern within a genus otherwise seemingly dominated by Northern Hemisphere dispersal.

The saprotrophic Pleurotus ostreatus species complex: late Eocene origin in East Asia, multiple dispersal, and complex speciation

“…Molecular-based biogeographic studies of macrofungi have mainly focused on ectomycorrhizal fungi (EMF) with wide geographic distributions (Cai et al 2014;Feng et al 2012;Han et al 2018;Hibbett and Matheny 2009;Hosaka et al 2008;Sánchez-Ramríez et al 2015;Truong et al 2017). Saprotrophic fungi (SPF) have a worldwide distribution and also play critical roles in ecosystem function, soil health, and human and animal nutrition (Austin et al 2004;McGonigle 1995;Rayner and Boddy 1988;Wolfe et al 2012).…”

Bats, Bat Flies, and Fungi: Exploring Uncharted Waters

“…However, this would be less surprising given a potential Gondwanan origin. Similarly, in another group of fungi (genus Amanita), researchers have identified taxa in southern South America to be grouped with relatives from Australia in a clade dating back to 34.5 million years ago, which fits with the timing of the fragmentation of South American, Australian, and Antarctic Plates (Truong et al 2017).…”

Loose Ends in the Cortinarius Phylogeny: Five New Myxotelamonoid Species Indicate a High Diversity of These Ectomycorrhizal Fungi with South American Nothofagaceae

“…“Southern Gondwana” connections are often explained by the presence of specific host plants in the Southern Hemisphere that are absent in other regions and vice versa [ 56 , 57 , 58 ]. Due to their association with Nothofagaceae forests, Southern Gondwanan connections could also be assumed for several lineages of Cortinarius , as already proposed for other genera of ectomycorrhizal fungi [ 59 , 60 , 61 , 62 ].…”