Phyllactinia guttata
Encyclopedia
Phyllactinia guttata is a species of fungus
in the Erysiphaceae
family; the anamorph of this species is Ovulariopsis moricola. A plant pathogen distributed in temperate
regions, P. guttata causes a powdery mildew
on leaves and stems on a broad range of host plants; many records of infection are from Corylus species, like filbert (Corylus maxima) and hazel (Corylus avellana
). Once thought to be conspecific with Phyllactinia chorisiae, a 1997 study proved that they are in fact separate species.
Microscopically, P. guttata is characterized by large ascomata, long narrow pointed appendages with bulbous swellings at base, 2- or 3-spored asci
with large ascospore
s; the ascomata also have gelatinous cells with tufts of hypha
e somewhat resembling hairs. The cleistothecia are capable of dissemination and attachment to new growing surfaces by means of gelatinous penicillate cells.
, the species went through a number of name changes in the 1800s. Salmon's widely used 1900 monograph on the Erysiphaceae
established the name as Phyllactinia corylea for roughly half a century, until the starting date for the naming of fungi was moved, and the name was established as Phyllactinia guttata.
may be abundant and persistent, or scant and short-lived (evanescent). The cleistothecia can become large (216–245 µm
), with soft wall tissue, and obscure cellular structure and cracks and wrinkles (reticulations).
The cleistothecia typically develop 8–12 easily detachable hyaline
appendages that vary in length from 191–290 µm long. The asci
are 4 to 5 to 20 or more, ovate, supported by small stalk-like structures (pedicellate), with dimensions of 72–83 by 32–40 µm. There are typically 2 spore
s per ascus, sometimes 3 or 4, and they are 31–36 by 21–25 µm.
The cells attached to the upper part of the ascomata that resemble hairs are known as penicillate cells; they are made of foots and filaments. The filaments can gelatinize by absorbing water and are thought to function in helping the ascomata adhere to the surface on which they grow, like the underside of leaves. In P. guttata, the foots are cylindrical, irregular in width, 32–72 by 7.5–25 µm, and divided into 2–10 branchlets in the upper part. Each branchlet is short, bulbous, with filaments being 20–42 µm, somewhat shorter than the foots, which are 2–4 µm wide. The short, bulbous branchlets on the multi-branched upper part of the foots are unique among the Phyllactinia and are a distinguishing taxonomic characteristic of this species.
regions of the world, such as China, India, Iran, Japan, Korea, Turkey, the former USSR, Europe (widely distributed), Canada, and USA. This species can infect a wide variety of hosts in many plant families. Examples include species from the Betulaceae
family (Betula, Carpinus, Corylus, Ostrya
), the Fagaceae
(Castanea
, Fagus
, Quercus) and the Juglandaceae
(Juglans, Platycarya
, Pterocarya). It is also found on the genera Acer, Aesculus
, Aralia
, Asclepias
, Azalea
, Buxus
, Catalpa
, Chionanthus
, Cornus, Frangula, Hedera, Humulus, Paliurus
, Populus, Prunus
, Rhamnus, Ribes
, Salix, Sorbus
, Syringa, and Ulmus. P. guttata is a host for the fungicolous hyphomycete
Cladosporium uredinicola.
Fungus
A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds , as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from plants, animals, and bacteria...
in the Erysiphaceae
Erysiphaceae
The Erysiphaceae are fungal family of the order Erysiphales. The family contains many of the powdery mildews.-Genera:*Arthrocladiella*Blumeria*Brasiliomyces*Bulbomicrosphaera*Bulbouncinula*Caespitotheca...
family; the anamorph of this species is Ovulariopsis moricola. A plant pathogen distributed in temperate
Temperate
In geography, temperate or tepid latitudes of the globe lie between the tropics and the polar circles. The changes in these regions between summer and winter are generally relatively moderate, rather than extreme hot or cold...
regions, P. guttata causes a powdery mildew
Powdery mildew
Powdery mildew is a fungal disease that affects a wide range of plants. Powdery mildew diseases are caused by many different species of fungi in the order Erysiphales. It is one of the easier diseases to spot, as its symptoms are quite distinctive. Infected plants display white powdery spots on the...
on leaves and stems on a broad range of host plants; many records of infection are from Corylus species, like filbert (Corylus maxima) and hazel (Corylus avellana
Corylus avellana
Corylus avellana, the Common Hazel, is a species of hazel native to Europe and western Asia, from the British Isles south to Iberia, Greece, Turkey and Cyprus, north to central Scandinavia, and east to the central Ural Mountains, the Caucasus, and northwestern Iran. It is an important component of...
). Once thought to be conspecific with Phyllactinia chorisiae, a 1997 study proved that they are in fact separate species.
Microscopically, P. guttata is characterized by large ascomata, long narrow pointed appendages with bulbous swellings at base, 2- or 3-spored asci
Ascus
An ascus is the sexual spore-bearing cell produced in ascomycete fungi. On average, asci normally contain eight ascospores, produced by a meiotic cell division followed, in most species, by a mitotic cell division. However, asci in some genera or species can number one , two, four, or multiples...
with large ascospore
Ascospore
An ascospore is a spore contained in an ascus or that was produced inside an ascus. This kind of spore is specific to fungi classified as ascomycetes ....
s; the ascomata also have gelatinous cells with tufts of hypha
Hypha
A hypha is a long, branching filamentous structure of a fungus, and also of unrelated Actinobacteria. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium; yeasts are unicellular fungi that do not grow as hyphae.-Structure:A hypha consists of one or...
e somewhat resembling hairs. The cleistothecia are capable of dissemination and attachment to new growing surfaces by means of gelatinous penicillate cells.
Taxonomy
Originally named in 1801 as Sclerotium erysiphe by Christian Hendrik PersoonChristian Hendrik Persoon
Christiaan Hendrik Persoon was a mycologist who made additions to Linnaeus' mushroom taxonomy.-Early life:...
, the species went through a number of name changes in the 1800s. Salmon's widely used 1900 monograph on the Erysiphaceae
Erysiphaceae
The Erysiphaceae are fungal family of the order Erysiphales. The family contains many of the powdery mildews.-Genera:*Arthrocladiella*Blumeria*Brasiliomyces*Bulbomicrosphaera*Bulbouncinula*Caespitotheca...
established the name as Phyllactinia corylea for roughly half a century, until the starting date for the naming of fungi was moved, and the name was established as Phyllactinia guttata.
Description
The myceliumMycelium
thumb|right|Fungal myceliaMycelium is the vegetative part of a fungus, consisting of a mass of branching, thread-like hyphae. The mass of hyphae is sometimes called shiro, especially within the fairy ring fungi. Fungal colonies composed of mycelia are found in soil and on or within many other...
may be abundant and persistent, or scant and short-lived (evanescent). The cleistothecia can become large (216–245 µm
Micrometre
A micrometer , is by definition 1×10-6 of a meter .In plain English, it means one-millionth of a meter . Its unit symbol in the International System of Units is μm...
), with soft wall tissue, and obscure cellular structure and cracks and wrinkles (reticulations).
Hyaline
The term hyaline denotes a substance with a glass-like appearance.-Histopathology:In histopathological medical usage, a hyaline substance appears glassy and pink after being stained with haematoxylin and eosin — usually it is an acellular, proteinaceous material...
appendages that vary in length from 191–290 µm long. The asci
Ascus
An ascus is the sexual spore-bearing cell produced in ascomycete fungi. On average, asci normally contain eight ascospores, produced by a meiotic cell division followed, in most species, by a mitotic cell division. However, asci in some genera or species can number one , two, four, or multiples...
are 4 to 5 to 20 or more, ovate, supported by small stalk-like structures (pedicellate), with dimensions of 72–83 by 32–40 µm. There are typically 2 spore
Spore
In biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions. Spores form part of the life cycles of many bacteria, plants, algae, fungi and some protozoa. According to scientist Dr...
s per ascus, sometimes 3 or 4, and they are 31–36 by 21–25 µm.
The cells attached to the upper part of the ascomata that resemble hairs are known as penicillate cells; they are made of foots and filaments. The filaments can gelatinize by absorbing water and are thought to function in helping the ascomata adhere to the surface on which they grow, like the underside of leaves. In P. guttata, the foots are cylindrical, irregular in width, 32–72 by 7.5–25 µm, and divided into 2–10 branchlets in the upper part. Each branchlet is short, bulbous, with filaments being 20–42 µm, somewhat shorter than the foots, which are 2–4 µm wide. The short, bulbous branchlets on the multi-branched upper part of the foots are unique among the Phyllactinia and are a distinguishing taxonomic characteristic of this species.
Habitat and distribution
P. guttula is wistributed in temperateTemperate
In geography, temperate or tepid latitudes of the globe lie between the tropics and the polar circles. The changes in these regions between summer and winter are generally relatively moderate, rather than extreme hot or cold...
regions of the world, such as China, India, Iran, Japan, Korea, Turkey, the former USSR, Europe (widely distributed), Canada, and USA. This species can infect a wide variety of hosts in many plant families. Examples include species from the Betulaceae
Betulaceae
Betulaceae, or the Birch Family, includes six genera of deciduous nut-bearing trees and shrubs, including the birches, alders, hazels, hornbeams and hop-hornbeams, numbering about 130 species...
family (Betula, Carpinus, Corylus, Ostrya
Ostrya
Ostrya is a genus of eight to ten small deciduous trees belonging to the birch family Betulaceae. Its common name is Hophornbeam in American English and Hop-hornbeam in British English. It may also be called ironwood, a name shared with a number of other plants.The genus is native in southern...
), the Fagaceae
Fagaceae
The family Fagaceae, or beech family, comprises about 900 species of both evergreen and deciduous trees and shrubs, which are characterized by alternate simple leaves with pinnate venation, unisexual flowers in the form of catkins, and fruit in the form of cup-like nuts. Fagaceous leaves are often...
(Castanea
Castanea
Castanea can mean:* Castanea , a plant genus including the chestnuts and chinkapins* Castanea, Pennsylvania, a census-designated place * Castanea Township, Pennsylvania, which surrounds the CDP of the same name...
, Fagus
Beech
Beech is a genus of ten species of deciduous trees in the family Fagaceae, native to temperate Europe, Asia and North America.-Habit:...
, Quercus) and the Juglandaceae
Juglandaceae
The Juglandaceae, also known as the Walnut Family, is a family of trees, or sometimes shrubs, in the order Fagales. Various members of this family are native to the Americas, Eurasia, and Southeast Asia....
(Juglans, Platycarya
Platycarya
Platycarya is a genus of flowering plants in the family Juglandaceae, usually treated as comprising a single species Platycarya strobilacea, though one to two additional species are accepted by some authors. It is native to eastern Asia in China, Korea, and Japan.It is a deciduous tree growing to...
, Pterocarya). It is also found on the genera Acer, Aesculus
Aesculus
The genus Aesculus comprises 13-19 species of woody trees and shrubs native to the temperate northern hemisphere, with 6 species native to North America and 7-13 species native to Eurasia; there are also several hybrids. Species are deciduous or evergreen...
, Aralia
Aralia
Aralia , or Spikenard, is a genus of the plant family Araliaceae, consisting of 68 accepted species of deciduous or evergreen trees, shrubs, and rhizomatous herbaceous perennials. The genus is native to Asia and the Americas, with most species occurring in mountain woodlands...
, Asclepias
Asclepias
Asclepias L. , the milkweeds, is a genus of herbaceous perennial, dicotyledonous plants that contains over 140 known species...
, Azalea
Azalea
Azaleas are flowering shrubs comprising two of the eight subgenera of the genus Rhododendron, Pentanthera and Tsutsuji . Azaleas bloom in spring, their flowers often lasting several weeks...
, Buxus
Buxus
Buxus is a genus of about 70 species in the family Buxaceae. Common names include box or boxwood ....
, Catalpa
Catalpa
Catalpa, commonly called catalpa or catawba, is a genus of flowering plants in the trumpet vine family, Bignoniaceae, native to warm temperate regions of North America, the Caribbean, and East Asia....
, Chionanthus
Chionanthus
Chionanthus is a genus of about 80 species of flowering plants in the family Oleaceae.The genus has a wide distribution primarily in the tropics and subtropics, but with two species extending north into temperate regions, one in eastern Asia and one in eastern North America...
, Cornus, Frangula, Hedera, Humulus, Paliurus
Paliurus
Paliurus is a genus of flowering plants in the family Rhamnaceae. The eight species are native to warm, dry regions of Eurasia and North Africa from Morocco and Spain east to Japan and Taiwan.-Description:...
, Populus, Prunus
Prunus
Prunus is a genus of trees and shrubs, which includes the plums, cherries, peaches, apricots and almonds. There are around 430 species spread throughout the northern temperate regions of the globe. Many members of the genus are widely cultivated for fruit and ornament.-Botany:Members of the genus...
, Rhamnus, Ribes
Ribes
Ribes is a genus of about 150 species of flowering plants native throughout the temperate regions of the Northern Hemisphere. It is usually treated as the only genus in the family Grossulariaceae. Seven subgenera are recognized....
, Salix, Sorbus
Sorbus
Sorbus is a genus of about 100–200 species of trees and shrubs in the subfamily Maloideae of the Rose family Rosaceae. Species of Sorbus are commonly known as whitebeam, rowan, service tree, and mountain ash...
, Syringa, and Ulmus. P. guttata is a host for the fungicolous hyphomycete
Hyphomycetes
Hyphomycetes is an obsolete class of fungi in the equally obsolete phylum Deuteromycota that lack fruiting bodies. Most hyphomycetes have now been assigned to the Ascomycota, mainly as a result of DNA sequencing, but many remain unassigned...
Cladosporium uredinicola.
External links
- Index Fungorum Synonyms