Publication Date:
2024-02-08
Description:
Ambrosia beetles farm specialised fungi in sapwood tunnels and use pocket-like organs called mycangia to carry propagules of the fungal cultivars. Ambrosia fungi selectively grow in mycangia, which is central
\nto the symbiosis, but the history of coevolution between fungal cultivars and mycangia is poorly understood. The
\nfungal family Ceratocystidaceae previously included three ambrosial genera (Ambrosiella, Meredithiella, and Phialophoropsis), each farmed by one of three distantly related tribes of ambrosia beetles with unique and relatively
\nlarge mycangium types. Studies on the phylogenetic relationships and evolutionary histories of these three genera
\nwere expanded with the previously unstudied ambrosia fungi associated with a fourth mycangium type, that of the
\ntribe Scolytoplatypodini. Using ITS rDNA barcoding and a concatenated dataset of six loci (28S rDNA, 18S rDNA,
\ntef1-\xce\xb1, tub, mcm7, and rpl1), a comprehensive phylogeny of the family Ceratocystidaceae was developed, including
\nInodoromyces interjectus gen. & sp. nov., a non-ambrosial species that is closely related to the family. Three minor
\nmorphological variants of the pronotal disk mycangium of the Scolytoplatypodini were associated with ambrosia
\nfungi in three respective clades of Ceratocystidaceae: Wolfgangiella gen. nov., Toshionella gen. nov., and Ambrosiella remansi sp. nov. Closely-related species that are not symbionts of ambrosia beetles are accommodated by
\nCatunica adiposa gen. & comb. nov. and Solaloca norvegica gen. & comb. nov. The divergent morphology of the
\nambrosial genera and their phylogenetic placement among non-ambrosial genera suggest three domestication
\nevents in the Ceratocystidaceae. Estimated divergence dates for the ambrosia fungi and mycangia suggest that
\nScolytoplatypodini mycangia may have been the first to acquire Ceratocystidaceae symbionts and other ambrosial
\nfungal genera emerged shortly after the evolution of new mycangium types. There is no evidence of reversion to a
\nnon-ambrosial lifestyle in the mycangial symbionts.
Keywords:
Ecology
;
Evolution
;
Behavior and Systematics
;
14 new taxa
;
Microascales
;
Scolytinae
;
symbiosis
;
two new typifications
Repository Name:
National Museum of Natural History, Netherlands
Type:
info:eu-repo/semantics/article
Format:
application/pdf
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