In the "1KFG: Deep Sequencing of Ecologically-relevant Dikarya"
project (CSP1974), we are sequencing keystone lineages of
plant-interacting fungi and saprophytic fungi that are of special
ecological importance for understanding terrestrial ecosystems. In
addition, comparative genome analysis with saprotrophic,
mycorrhizal and pathogenic fungi will provide new insights into the
specific and conserved adaptations associated with each fungal
lifestyle.
Ischnoderma benzoinum
IVC119
This polypore is wide-spread in the conifer forests of boreal and
north temperate Eurasia. It inhabits dead conifer trunks and causes
white rot. In Europe, Picea abies is the favorite host.
The annual fruiting bodies often emit a pleasant, fruity
smell.
Ischnoderma is a small genus, with only two commonly
recognized, very similar species. They belong to the Polyporales
(Agaricomycetes, Basidiomycota) and represent an isolated lineage
within the order, labelled as the family Ischnodermataceae.
Phylogenetic analysis of Justo et al. (2017) placed the origin of
their lineage at the base of the Polyporales family tree, though
with no support. The position of this genus and family is important
in understanding evolution in the Polyporales. This order is
arguably the single most important group containing both white and
brown rot fungi. Describing the genetic basis of wood decomposition
systems in various lineages will benefit the evolutionary
reconstruction, as well as practical application, of fungal wood
decomposition ability.
Although morphologically Ischnoderma are no different
from other Polyporales, they do exhibit a rare combination of
characters, being white rot fungi with a bipolar mating system
(Nobles 1965). Most Polyporales have a tetrapolar mating system,
and most species with a bipolar system are brown rot fungi such as
Fomitopsidaceae (Ryvarden 1991; Nobles 1971; Nakasone 1990). It is
unclear why rot type and mating system seem to correlate - it may
be a coincidence that the ancestor of brown rots happened to be
bipolar, or there may be other biological processes behind this
trend. Ischnoderma is not a unique genus in this sense -
for instance Bjerkandera and Phlebia s.s. are
also bipolar - but since it represents a basal lineage it could
offer an interesting perspective to the evolution of mating systems
in the Polyporales.
The genome strain (IVC 119) derives from a hyphal transplant of a
fruiting body (leg. Ilya Viner 2020_22), collected in Helsinki,
Finland, on Picea abies.
Researchers who wish to publish analyses using data from
unpublished CSP genomes are respectfully required to contact the PI
and JGI to avoid potential conflicts on data use and coordinate
other publications with the CSP master paper(s).
References:
- Justo A, Miettinen O, Floudas D, Ortiz-Santana B, Sjökvist E, Lindner D, Nakasone K, Niemelä T, Larsson K-H, Ryvarden L, Hibbett DS (2017) A revised family-level classification of the Polyporales (Basidiomycota). Fungal Biol 121 (9):798-824. doi:10.1016/j.funbio.2017.05.010
- Nakasone KK (1990) Cultural studies and identification of wood-inhabiting Corticiaceaea and selected hymenomycetes from North America. Mycologia Memoir 15:1-412
- Nobles MK (1965) Identification of cultures of wood-inhabiting Hymenomycetes. Canadian Journal of Botany 43 (9):1097-1139
- Nobles MK (1971) Cultural characters as a guide to the taxonomy of the Polyporaceae. In:Petersen RH (ed) Evolution in the higher Basidiomycetes. The University of Tennessee Press, Knoxville, pp 169-196
- Ryvarden L (1991) Genera of polypores. Nomenclature and taxonomy. Synopsis Fungorum 5:1-363