Long evolutionary history of Glomeraceae explains wide distribution and diversity of AMF associated to the mycoheterotroph Arachnitis uniflora Phil. (Corsiaceae).

ACOSTA M. C.; BIDARTONDO, M.; COFRÉ, N.; SÉRSIC, A.N.; RENNY, M.; DOMÍNGUEZ, L.

ANNALS OF BOTANY

OXFORD UNIV PRESS

Lugar: Oxford; Año: 2017

0305-7364

Background and Aims. Molecular tools allow to understand that not allmycoheterotrophs are extreme specialists; indeed, some mycoheterotrophic plantshave the ability to associate with more than one fungal family. We identified fungal DNA taxa associated with Arachnitis uniflora across its geographic range, and tested the role of historical events and current environmental, geographical and altitudinal variables on the fungal genetic diversity.Methods. We sampled fungi of A. uniflora in 25 sites, obtained 104 fungal DNAsequences from the 18S ribosomal rDNA gene. Phylogenetic relationships werereconstructed; genetic diversity was calculated and main divergences divergentlineages were dated. Phylogeographic analysis was performed with the mainfungal clade. Fungal diversity associations with environmental factors wereexplored.Key results. Three Glomeromycotan families were found, though Glomeraceaewas the dominant symbiont, building a main clade (Arachnitis clade) originatedaround the Upper Cretaceous, which retrieved 20 haplotypes. High geneticdiversity was found in Bolivia and both in northern and southern Patagonia, which was also associated with temperature, rainfall and soil features.Conclusions. Fungal genetic diversity and its distribution were explained by both, an ancient evolutionary history of Glomeraceae, and micro-scale environmental conditions in a geographical mosaic pattern. New fungiThe two families not previously found in A. uniflora would may represent facultative associations.