Phyllactinia guttata | |
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Various stages in the life cycle of Phyllactinia guttata. Fig 1. Natural size, on chestnut leaf. 2. Perithecium enlarged. 3. Two asci. 4.Three sporidia. 5.Conidia-bearing hyphae. 6.Conidium germinating. | |
Scientific classification | |
Kingdom: | Fungi |
Division: | Ascomycota |
Class: | Leotiomycetes |
Order: | Erysiphales |
Family: | Erysiphaceae |
Genus: | Phyllactinia |
Species: | P. guttata |
Binomial name | |
Phyllactinia guttata (Wallr.) Lév. | |
Synonyms | |
Ovulariopsis moricola |
Phyllactinia guttata is a species of fungus in the family Erysiphaceae; 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. [1]
Microscopically, P. guttata is characterized by large ascomata, long narrow pointed appendages with bulbous swellings at base, 2- or 3-spored asci with large ascospores; the ascomata also have gelatinous cells with tufts of hyphae somewhat resembling hairs. [2] The cleistothecia are capable of dissemination and attachment to new growing surfaces by means of gelatinous penicillate cells.
Originally named in 1801 as Sclerotium erysiphe by Christian Hendrik Persoon, the species went through a number of name changes in the 1800s. Salmon's widely used 1900 monograph on the Erysiphaceae [3] 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. [4]
The mycelium may be abundant and persistent, or scant and short-lived (evanescent). [5] 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 spores per ascus, sometimes 3 or 4, and they are 31–36 by 21–25 μm. [6]
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. [7] 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. [2]
Phyllactinia guttula is distributed throughout temperate 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. [8] 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, Morus, Paliurus , Populus , Prunus , Rhamnus , Ribes , Salix , Sorbus , Syringa , and Ulmus . [9] P. guttata is a host for the fungicolous hyphomycete Cladosporium uredinicola . [10]
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 defining feature of this fungal group is the "ascus", a microscopic sexual structure in which nonmotile spores, called ascospores, are formed. However, some species of the Ascomycota are asexual, meaning that they do not have a sexual cycle and thus do not form asci or ascospores. Familiar examples of sac fungi include morels, truffles, brewer's yeast and baker's yeast, dead man's fingers, and cup fungi. The fungal symbionts in the majority of lichens such as Cladonia belong to the Ascomycota.
An ascocarp, or ascoma, is the fruiting body (sporocarp) of an ascomycete phylum fungus. It consists of very tightly interwoven hyphae and may contain millions of asci, each of which typically contains four to eight ascospores. Ascocarps are most commonly bowl-shaped (apothecia) but may take on a spherical or flask-like form that has a pore opening to release spores (perithecia) or no opening (cleistothecia).
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, with Podosphaera xanthii being the most commonly reported cause. Erysiphe cichoracearum was formerly reported to be the primary causal organism throughout most of the world. Powdery mildew is one of the easier plant diseases to identify, as its symptoms are quite distinctive. Infected plants display white powdery spots on the leaves and stems. The lower leaves are the most affected, but the mildew can appear on any above-ground part of the plant. As the disease progresses, the spots get larger and denser as large numbers of asexual spores are formed, and the mildew may spread up and down the length of the plant.
Erysiphales are an order of ascomycete fungi. The order contains one family, Erysiphaceae. Many of them cause plant diseases called powdery mildew.
Erysiphe betae is a plant pathogen. It is a form of powdery mildew that can affect crops of sugar beet, when it can cause up to a 30% yield loss. The fungus occurs worldwide in all regions where sugar beet is grown and it also infects other edible crops, e.g. beetroot.
Brasiliomyces malachrae is a species of fungus in the family Erysiphaceae. It is a plant pathogen that grows on Gossypium, Lavatera assurgentiflora, Malachra capitata, Malvastrum coromandelianum, and species of Malvaceae. It is found in South America.
Podosphaera pannosa is a plant pathogen. It produces a powdery mildew on members of the rose family.
Erysiphe heraclei is a plant pathogen that causes powdery mildew on several species including dill, carrot and parsley.
Spathularia flavida, commonly known as the yellow earth tongue, the yellow fan, or the fairy fan, is an ascomycete fungus found in coniferous forests of Asia, Europe and North America. It produces a small, fan- or spoon-shaped fruit body with a flat, wavy or lobed cream to yellow colored "head" raised on a white to cream stalk. The height is usually approximately 2–5 cm (0.8–2.0 in), and up to 8 cm (3.1 in). The fungus fruits on the ground in mosses, forest duff or humus, and fruit bodies may occur singly, in large groups, or in fairy rings. The spores produced by the fungus are needle-like, and up to 95 micrometres long. Several varieties have been described that differ largely in their microscopic characteristics. S. flavida has been described by authorities variously as inedible, of unknown edibility, or edible but tough.
Cookeina is a genus of cup fungi in the family Sarcoscyphaceae, members of which may be found in tropical and subtropical regions of the world. Species may be found on fallen branches of angiosperms, trunks, and sometimes on fruits. The Temuans of Peninsular Malaysia are reported to use certain species from this genus as food, and also as a bait for fishing, where it is rubbed against the hook.
Aquamarina is a fungal genus in the class Dothideomycetes. It is a monotypic genus, containing the single marine species Aquamarina speciosa, originally found in North Carolina, and distributed in the Atlantic Coast of the United States. The bluish-green species fruits exclusively in the lower parts of dying culms of the saltmarsh plant Juncus roemerianus.
Sphaerotheca castagnei is a species of ascomycete fungus in the family Erysiphaceae. A plant pathogen, it causes a form of powdery mildew.
Microstoma floccosum is a species in the cup fungus family Sarcoscyphaceae. It is recognizable by its deep funnel-shaped, scarlet-colored fruit bodies bearing white hairs on the exterior. Found in the United States and Asia, it grows on partially buried sticks and twigs of oak trees.
Polytolypa is a monotypic genus of fungus containing the single species Polytolypa hystricis. First classified in the Onygenaceae family, as of 2008 it is considered to be in the Ajellomycetaceae, although there is still uncertainty as to its phylogenetic relationships with other similar genera. This species is only known from a single specimen derived in the laboratory from a specimen of dung of the North American porcupine, Erethizon dorsatum, collected in Ontario, Canada. Polytolypa hystricis contains bioactive compounds that have antifungal activity.
The Loramycetaceae are a family of fungi in the Ascomycota, class Leotiomycetes. This is a monotypic taxon, containing the single genus Loramyces; the genus contains two aquatic species, L. juncicola, named by American mycologist William H. Weston in 1929, and L. macrosporus, first described by C.T. Ingold and B. Chapman in 1952.
Keissleriella rara is a rare species of fungus in the family Lophiostomataceae. The species fruits exclusively on dead or dying standing culms of the saltmarsh plant Juncus roemerianus. It is known only from the Atlantic Coast of North Carolina.
Coccomyces dentatus is a species of fungus in the family Rhytismataceae. A widespread species, particularly in temperate areas, it colonizes the dead fallen leaves of vascular plants, particularly oak and chestnut. The fungus apothecia, which form in the epidermal layer of the leaf host, resemble dark hexagonal spots scattered on a multi-colored mosaic pattern bounded by thin black lines. When mature, the apothecia open by triangular flaps to release spores. The anamorph form of C. dentatus is Tricladiopsis flagelliformis. Lookalike species can be distinguished by the shape of the apothecia, or by microscopic characteristics.
Uncinocarpus reesii is a species of saprotrophic microfungi that grows in soil and on keratinous materials such as hair, feathers and skin. It was the first species to be designated as part of the genus Uncinocarpus, owing in part to its characteristic development of hooked (uncinate) appendages. As the closest non-pathogenic relative of Coccidioides immitis and C. posadasii, it has become a subject of research interest.
Cercophora areolata is a member of the Ascomycota division, and is grouped into the Lasiosphaeriaceae family based on morphology. C. areolata is a coprophilous fungus that has been most recently isolated from porcupine dung. Defining features of C. areolata include: 1) ovoid-conical, glabrous ascomata, 2) black, carbonaceous, areolate peridium and 3) clavate-shaped, single-walled asci. From studies on C. areolata, this fungus produces multiple antifungal compounds, which inhibit other competitor fungi.
Podosphaera filipendulae is a fungal species that belongs to the genus Podosphaera and the order Erysiphaceae. It was first described with meadowsweet as the host plant.