''Xenodevriesia strelitziicola'' is a
pathogenic
In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a ger ...
ascomycete
Ascomycota is a phylum of the kingdom Fungi that, together with the Basidiomycota, forms the subkingdom Dikarya. Its members are commonly known as the sac fungi or ascomycetes. It is the largest phylum of Fungi, with over 64,000 species. The d ...
fungus in the
class
Class or The Class may refer to:
Common uses not otherwise categorized
* Class (biology), a taxonomic rank
* Class (knowledge representation), a collection of individuals or objects
* Class (philosophy), an analytical concept used differently ...
Dothideomycetes
Dothideomycetes is the largest and most diverse class of ascomycete fungi. It comprises 11 orders 90 families, 1300 genera and over 19,000 known species. Traditionally, most of its members were included in the loculoascomycetes, which is not p ...
that infects the
South Africa
South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring count ...
n plant ''
Strelitzia
''Strelitzia'' is a genus of five species of perennial plants, native to South Africa. It belongs to the plant family Strelitziaceae. The genus is named after Queen Charlotte of the United Kingdom, who was born a princess of the house of Meckl ...
''.
It is the only species of the
monotypic
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...
''Xenodevriesia'' and
family
Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...
Xenodevriesiaceae.
Morphology and reproduction
''Xenodevriesia''
mycelium
Mycelium (plural mycelia) is a root-like structure of a fungus consisting of a mass of branching, thread-like hyphae. Fungal colonies composed of mycelium are found in and on soil and many other substrates. A typical single spore germinates in ...
consists of medium brown, smooth, septate, branched
hyphae
A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium.
Structure
A hypha consists of one or ...
. The
conidiophores
A conidium ( ; ), sometimes termed an asexual chlamydospore or chlamydoconidium (), is an asexual, non-motile spore of a fungus. The word ''conidium'' comes from the Ancient Greek word for dust, ('). They are also called mitospores due to the ...
are
dimorphic
Dimorphism or dimorphic may refer to:
Science
* Dimorphic root systems, plant roots with two distinctive forms for two separate functions
* Sexual dimorphism, a phenotypic difference between males and females of the same species
* Nuclear dimorp ...
: there are microconidiophores and macroconidiophores.
:The microconidiophores are reduced to conidiogenous cells (i.e. capable of generating
conidia
A conidium ( ; ), sometimes termed an asexual chlamydospore or chlamydoconidium (), is an asexual, non-motile spore of a fungus. The word ''conidium'' comes from the Ancient Greek word for dust, ('). They are also called mitospores due to th ...
) on hyphae that are erect, cylindrical, medium brown in color, smooth, with truncated ends and proliferating
sympodially
Sympodial growth is a bifurcating branching pattern where one branch develops more strongly than the other, resulting in the stronger branches forming the primary shoot and the weaker branches appearing laterally. A sympodium, also referred to a ...
. The conidiogenous cells appear at terminal or lateral locations on top of branched conidiophores; they are also medium brown in color, smooth and cylindrical, and also grow sympodially.
:The macroconidiophores are erect, cylindrical, between straight and sinuous in shape, medium brown in color, smooth, and unbranched or branched only above.
The
conidia
A conidium ( ; ), sometimes termed an asexual chlamydospore or chlamydoconidium (), is an asexual, non-motile spore of a fungus. The word ''conidium'' comes from the Ancient Greek word for dust, ('). They are also called mitospores due to th ...
themselves are smooth, guttulate (i.e. spores containing one or more oil-like globules),
between subcylindrical and narrowly obclavate in shape, with an apex obtuse or truncate and a truncate base; they occur in branched chains that are widest at the basal septum. The
hila Hila may refer to:
*plural form of Hilum
*Village in Israel: Mitzpe Hila
*Hila (given name), in Hebrew
* For the Islamic concept of "stratagem", see Ḥiyal
*Hila, Ambon, the town on the Indonesian island of Ambon where Fort Amsterdam was sited. ...
are inconspicuous or somewhat darkened and thickened, and aren't
refractive
In physics, refraction is the redirection of a wave as it passes from one medium to another. The redirection can be caused by the wave's change in speed or by a change in the medium. Refraction of light is the most commonly observed phenomen ...
.
There has been no observation of
chlamydospores
A chlamydospore is the thick-walled large resting spore of several kinds of fungi, including Ascomycota such as '' Candida'', Basidiomycota such as '' Panus'', and various Mortierellales species. It is the life-stage which survives in unfavourable ...
.
In particular, ''X. strelitziicola'' presents hyphae measuring 2–3 µm in width; microconidiophores measuring 4–7 x 2–3 µm; conidiogenous cells measuiring 7–15 x 2.5–3 µm; macroconidiophores measuring measuring 30–100 x 2.5–3 µm; and
conidia
A conidium ( ; ), sometimes termed an asexual chlamydospore or chlamydoconidium (), is an asexual, non-motile spore of a fungus. The word ''conidium'' comes from the Ancient Greek word for dust, ('). They are also called mitospores due to th ...
with
hila Hila may refer to:
*plural form of Hilum
*Village in Israel: Mitzpe Hila
*Hila (given name), in Hebrew
* For the Islamic concept of "stratagem", see Ḥiyal
*Hila, Ambon, the town on the Indonesian island of Ambon where Fort Amsterdam was sited. ...
that are 1-1.5 µm wide.
Taxonomy and etymology
First described in 2009, the species was placed in the genus ''
Devriesia'', located in the family
Teratosphaeriaceae
Teratosphaeriaceae is a family of fungi in the order Capnodiales.
History
In 2007, this family was recognized as distinct from the genus ''Mycosphaerella'', where it had previously been located, based on phylogenies constructed with the Large S ...
, under the name ''Devriesia strelitziicola'', in which the
epithet
An epithet (, ), also byname, is a descriptive term (word or phrase) known for accompanying or occurring in place of a name and having entered common usage. It has various shades of meaning when applied to seemingly real or fictitious people, di ...
is a reference to the host ''
Strelitzia
''Strelitzia'' is a genus of five species of perennial plants, native to South Africa. It belongs to the plant family Strelitziaceae. The genus is named after Queen Charlotte of the United Kingdom, who was born a princess of the house of Meckl ...
''.
In 2019 it was moved to its own genus ''Xenodevriesia'' and its own family
Xenodevriesiaceae
''Xenodevriesia strelitziicola'' is a pathogenic ascomycete fungus in the class (biology), class Dothideomycetes that infects the South African plant ''Strelitzia''. It is the only species of the monotypic genus (biology), genus ''Xenodevriesia'' ...
, after a
phylogenetic analysis
In biology
Biology is the scientific study of life. It is a natural science with a broad scope but has several unifying themes that tie it together as a single, coherent field. For instance, all organisms are made up of cells that pro ...
of the entire
Dothideomycetes
Dothideomycetes is the largest and most diverse class of ascomycete fungi. It comprises 11 orders 90 families, 1300 genera and over 19,000 known species. Traditionally, most of its members were included in the loculoascomycetes, which is not p ...
class showed its independence from the genus ''
Devriesia''.
References
{{Taxonbar, from=Q114364017, ncbi=706560
Fungi described in 2019
Capnodiales