The online database Maarj<i>AM</i> reveals global and ecosystemic distribution patterns in arbuscular mycorrhizal fungi (Glomeromycota)

TLDR

The authors present MaarjAM, a new database compiling publicly available Glomeromycota DNA sequences and metadata to enable analysis of distribution and richness patterns. The database was constructed by collating SSU rRNA gene sequences and associated metadata from all suitable taxonomic and ecological publications. The database revealed 282 virtual taxa, most with limited distribution, a positive correlation between host taxonomic breadth and geographic range, and highlighted inconsistencies between molecular and traditional taxonomy as well as data gaps in major continents and ecosystems.

Abstract

• Here, we describe a new database, MaarjAM, that summarizes publicly available Glomeromycota DNA sequence data and associated metadata. The goal of the database is to facilitate the description of distribution and richness patterns in this group of fungi. • Small subunit (SSU) rRNA gene sequences and available metadata were collated from all suitable taxonomic and ecological publications. These data have been made accessible in an open-access database (http://maarjam.botany.ut.ee). • Two hundred and eighty-two SSU rRNA gene virtual taxa (VT) were described based on a comprehensive phylogenetic analysis of all collated Glomeromycota sequences. Two-thirds of VT showed limited distribution ranges, occurring in single current or historic continents or climatic zones. Those VT that associated with a taxonomically wide range of host plants also tended to have a wide geographical distribution, and vice versa. No relationships were detected between VT richness and latitude, elevation or vascular plant richness. • The collated Glomeromycota molecular diversity data suggest limited distribution ranges in most Glomeromycota taxa and a positive relationship between the width of a taxon's geographical range and its host taxonomic range. Inconsistencies between molecular and traditional taxonomy of Glomeromycota, and shortage of data from major continents and ecosystems, are highlighted.