First insights into the phylogeny of the order Cribrariales (Amoebozoa, Myxomycetes), with the definite exclusion of the genus Enteridium.

Abstract

The order Cribrariales is among the least studied higher groups in the Myxomycetes, with numerous taxonomic problems and scarce molecular data available in public databases. Of the three genera currently accepted, viz. Cribraria, Lindbladia, and Enteridium, the last one shows a set of morphological characters clearly disagreeing with the two former ones. Using a representative sampling and two unlinked loci (nuclear and mitochondrial SSU), we assessed the phylogenetic relationships in the bright-spored Myxomycetes (Lucisporomycetidae) and concluded that the genus Enteridium must be excluded from the order Cribrariales and placed instead within the order Trichiales, family Dianemataceae. We provide detailed explanations of why this genus has been misclassified in previous studies, and define its morphological and molecular boundaries, performing two necessary new combinations. On the other hand, the phylogeny of the order Cribrariales s.str. shows three main lineages that are distinguished as three subgenera, viz. C. subg. Cribraria, C. subg. Dictydium, and C. subg. Ionokylixsubg. nov., the first one including the genus Lindbladia deeply nested and therefore treated as a heterotypic synonym of Cribraria.