Dijigiella
From Wikipedia, the free encyclopedia
| Dijigiella | |
|---|---|
Scientific classification  | |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Lecanoromycetes |
| Order: | Teloschistales |
| Family: | Teloschistaceae |
| Genus: | Dijigiella S.Y.Kondr. & Lőkös (2017) |
| Type species | |
| Dijigiella kaernefeltiana S.Y.Kondr. (2017) | |
| Species | |
Dijigiella is a small genus of bark-dwelling lichens in the family Teloschistaceae.[1] It currently comprises two species. The genus was established in 2017 on the basis of DNA sequence data from Australian material that formed its own evolutionary branch, although later work has suggested that Dijigiella may not represent a distinct lineage and could be better merged with the related genus Teuvoahtiana. Both known species produce small, bright yellow to orange disc-shaped fruiting bodies on tree bark, often growing in dense clusters that are more conspicuous than the thin, greyish thallus beneath them. The genus is currently known only from Australia, where it occurs on the bark of shrubs and trees in open, dry habitats.
Dijigiella was introduced by Sergey Kondratyuk and László Lőkös in a 2017 revision of the family that used DNA sequences from three different genes (nuclear ITS, nuclear LSU and mitochondrial SSU) to redraw relationships within the group. In those analyses Dijigiella formed its own branch within the subfamily Brownlielloideae, separate from superficially similar genera such as Marchantiana that belong to a different subfamily. The genus was circumscribed to accommodate a small, well-supported lineage informally referred to as the Dijigiella kaernefeltiana group, and currently contains two Australian species, D. kaernefeltiana and D. subaggregata, which together define its morphological and molecular concept. Both species share a similar crustose growth form and bright yellow to orange fruiting bodies, and they group together in the combined three-gene phylogeny as a distinct branch of the Brownlielloideae. The authors expect that additional species will later be placed in Dijigiella, and note that several sorediate (powdery-reproducing) crusts from Australia, for which DNA data were not yet available, may belong to this lineage once sequenced.[2]
A later family-wide analysis of Teloschistaceae by Karina Wilk and co-workers raised problems with the original placement of Dijigiella in the newly created subfamily Brownlielloideae. They showed that Brownlielloideae had been defined using a mixed, or "chimeric", set of DNA sequences, with some of the sequences in fact belonging to quite different lichen families such as Umbilicariaceae, Acarosporaceae and members of the order Chaetothyriales. When those foreign sequences were removed and the phylogeny was recalculated using only verified Teloschistaceae data, the supposed Brownlielloideae species no longer formed a single natural group: instead they were scattered across the three established subfamilies, and the type genus Brownliella fell back into Teloschistoideae, making Brownlielloideae an artificial group and a synonym of that subfamily. In the corrected tree, the genuine sequences of Dijigiella do not form their own separate branch at all, but sit within the subfamily Xanthorioideae as part of a strongly supported Teuvoahtiana clade; on this basis Wilk and colleagues regarded Dijigiella as a putative synonym of Teuvoahtiana.[3] Other recent studies likewise placed Dijigiella in the Xanthorioideae, where it falls in the same well-supported clade as Teuvoahtiana, in line with the view that the two generic names represent the same lineage.[4][5]