Gymnosporangium globosum
Gymnosporangium globosum is a plant pathogen that causes cedar-hawthorn rust. Index Fungorum USDA ARS Fungal Database
Gymnosporangium libocedri
Gymnosporangium libocedri is a plant pathogen and rust fungus. It produces orange gelatinous growths on incense cedar in the spring, its secondary hosts include apple, hawthorn, mountain ash, pear and serviceberry. Index Fungorum USDA ARS Fungal Database PNW Plant Disease Handbook
Fungus
A fungus is any member of the 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, separate from the other eukaryotic life kingdoms of plants and animals. A characteristic that places fungi in a different kingdom from plants and some protists is chitin in their cell walls. Similar to animals, fungi are heterotrophs. Fungi do not photosynthesize. Growth is their means of mobility, except for spores, which may travel through the water. Fungi are the principal decomposers in ecological systems; these and other differences place fungi in a single group of related organisms, named the Eumycota, which share a common ancestor, an interpretation, strongly supported by molecular phylogenetics. This fungal group oomycetes; the discipline of biology devoted to the study of fungi is known as mycology. In the past, mycology was regarded as a branch of botany, although it is now known fungi are genetically more related to animals than to plants.
Abundant worldwide, most fungi are inconspicuous because of the small size of their structures, their cryptic lifestyles in soil or on dead matter. Fungi include symbionts of plants, animals, or other fungi and parasites, they may become noticeable when fruiting, either as molds. Fungi perform an essential role in the decomposition of organic matter and have fundamental roles in nutrient cycling and exchange in the environment, they have long been used in the form of mushrooms and truffles. Since the 1940s, fungi have been used for the production of antibiotics, more various enzymes produced by fungi are used industrially and in detergents. Fungi are used as biological pesticides to control weeds, plant diseases and insect pests. Many species produce bioactive compounds called mycotoxins, such as alkaloids and polyketides, that are toxic to animals including humans; the fruiting structures of a few species contain psychotropic compounds and are consumed recreationally or in traditional spiritual ceremonies.
Fungi can break down manufactured materials and buildings, become significant pathogens of humans and other animals. Losses of crops due to fungal diseases or food spoilage can have a large impact on human food supplies and local economies; the fungus kingdom encompasses an enormous diversity of taxa with varied ecologies, life cycle strategies, morphologies ranging from unicellular aquatic chytrids to large mushrooms. However, little is known of the true biodiversity of Kingdom Fungi, estimated at 2.2 million to 3.8 million species. Of these, only about 120,000 have been described, with over 8,000 species known to be detrimental to plants and at least 300 that can be pathogenic to humans. Since the pioneering 18th and 19th century taxonomical works of Carl Linnaeus, Christian Hendrik Persoon, Elias Magnus Fries, fungi have been classified according to their morphology or physiology. Advances in molecular genetics have opened the way for DNA analysis to be incorporated into taxonomy, which has sometimes challenged the historical groupings based on morphology and other traits.
Phylogenetic studies published in the last decade have helped reshape the classification within Kingdom Fungi, divided into one subkingdom, seven phyla, ten subphyla. The English word fungus is directly adopted from the Latin fungus, used in the writings of Horace and Pliny; this in turn is derived from the Greek word sphongos, which refers to the macroscopic structures and morphology of mushrooms and molds. The word mycology is derived from the Greek logos, it denotes the scientific study of fungi. The Latin adjectival form of "mycology" appeared as early as 1796 in a book on the subject by Christiaan Hendrik Persoon; the word appeared in English as early as 1824 in a book by Robert Kaye Greville. In 1836 the English naturalist Miles Joseph Berkeley's publication The English Flora of Sir James Edward Smith, Vol. 5. Refers to mycology as the study of fungi. A group of all the fungi present in a particular area or geographic region is known as mycobiota, e.g. "the mycobiota of Ireland". Before the introduction of molecular methods for phylogenetic analysis, taxonomists considered fungi to be members of the plant kingdom because of similarities in lifestyle: both fungi and plants are immobile, have similarities in general morphology and growth habitat.
Like plants, fungi grow in soil and, in the case of mushrooms, form conspicuous fruit bodies, which sometimes resemble plants such as mosses. The fungi are now considered a separate kingdom, distinct from both plants and animals, from which they appear to have diverged around one billion years ago; some morphological and genetic features are shared with other organisms, while others are unique to the fungi separating them from the other kingdoms: Shared features: With other euka
Romanus Adolf Hedwig
Romanus Adolf Hedwig, sometimes styled as Romano Adolpho Hedwigio or R. A. H. was a German botanist best known for his studies into pteridophytes, spermatophytes and bryology. He is the son of notable bryologist Johann Hedwig; the standard author abbreviation R. Hedw. is used to indicate this person as the author when citing a botanical name. Romanus worked with his father, illustrating the publication Filicum genera et species recentiori methodo accomodatae analytice descriptae in 1799. Following in his late father's footsteps, he was appointed as the Professor of Botany at the University of Leipzig in 1801. Romanus became good friends with Augustin Pyramus de Candolle, the two would send correspondences and exchange specimens. Romanus was thanked for his contributions in de Canolle's publication Flore française etc. Upon the death of Romanus in 1806, his personal herbarium was sold with some material being incorporated into his father's collection. Disquisitio ampullularum Lieberkühnii Physico-microscopica.
Sectio prima etc. Barth. 1797. Tremella nostoch: Commentatio etc. ex officina Bueschelia. 1798. Observationum botanicarum fasciculus primus. in Bibliopolio Schaeferiano. 1802. Genera plantarum secundum characteres differentiales ad Mirbelii editionem revisa et aucta edenda curavit. 1806
Rosaceae
Rosaceae, the rose family, is a medium-sized family of flowering plants, including 4,828 known species in 91 genera. The name is derived from the type genus Rosa. Among the most species-rich genera are Alchemilla, Crataegus, Cotoneaster and Prunus with about 200 species. However, all of these numbers should be seen as estimates – much taxonomic work remains; the family Rosaceae includes herbs and trees. Most species are deciduous, they are most diverse in the Northern Hemisphere. Several economically important products come from the Rosaceae, including many edible fruits and ornamental trees and shrubs; the Rosaceae have a cosmopolitan distribution, but are concentrated in the Northern Hemisphere in regions that are not desert or tropical rainforest. The family was traditionally divided into six subfamilies: Rosoideae, Maloideae, Amygdaloideae and Chrysobalanoideae, most of these were treated as families by various authors. More Chrysobalanoideae was placed in Malpighiales in molecular analyses and Neuradoideae has been assigned to Malvales.
Schulze-Menz, in Engler's Syllabus edited by Melchior recognized Rosoideae, Lyonothamnoideae, Spireoideae and Maloideae. They were diagnosed by the structure of the fruits. More recent work has identified. Hutchinson and Kalkman recognized only tribes. Takhtajan delimited 21 tribes in 10 subfamilies: Filipenduloideae, Ruboideae, Coleogynoideae, Amygdaloideae, Maloideae, Dichotomanthoideae. A more modern model comprises three subfamilies, one of which has remained the same. While the boundaries of the Rosaceae are not disputed, there is not general agreement as to how many genera it contains. Areas of divergent opinion include the treatment of Potentilla s.l. and Sorbus s.l.. Compounding the problem is that apomixis is common in several genera; this results in an uncertainty in the number of species contained in each of these genera, due to the difficulty of dividing apomictic complexes into species. For example, Cotoneaster contains between 70 and 300 species, Rosa around 100, Sorbus 100 to 200 species, Crataegus between 200 and 1,000, Alchemilla around 300 species, Potentilla 500, Rubus hundreds, or even thousands of species.
The phylogenetic relationships between the three subfamilies within Rosaceae are unresolved. There are three competing hypotheses: Amygdaloideae has been identified as the earliest branching subfamily by Chin et al. Li et al. Li et al. and Sun et al.. Most Zhang et al. recovered these relationships using whole plastid genomes: The sister relationship between Dryadoideae and Rosoideae is supported by the following shared morphological characters not found in Amygdaloideae: presence of stipules, separation of the hypanthium from the ovary, the fruits are achenes. Dryadoideae has been identified as the earliest branching subfamily by Potter. Most Xiang et al. recovered these relationships using nuclear transcriptomes: Rosoideae has been identified as the earliest branching subfamily by Morgan et al. Evans, Potter et al. Potter et al. Töpel et al. and Chen et al.. The following is taken from Potter et al.: The sister relationship between Amygdaloideae and Dryadoideae is supported by the following shared biochemical characters not found in Rosoideae: production of cyanogenic glycosides and production of sorbitol.
Rosaceae can be shrubs, or herbaceous plants. The herbs are perennials, but some annuals exist; the leaves are arranged spirally, but have an opposite arrangement in some species. They can be pinnately compound. Compound leaves appear in around 30 genera; the leaf margin is most serrate. Paired stipules are present, are a primitive feature within the family, independently lost in many groups of Amygdaloideae; the stipules are sometimes adnate to the petiole. Glands or extrafloral nectaries may be present on leaf petioles. Spines may be present on the rachis of compound leaves. Flowers of plants in the rose family are described as "showy", they are actinomorphic and always hermaphroditic. Rosaceae have five sepals, five petals, many spirally arranged stamens; the bases of the sepals and stamens are fused together to form a characteristic cup-like structure called a hypanthium. They can be arranged in spikes, or heads; the fruits occur in many varieties and were once considered the main characters for the definition of subfamilies amongst Rosaceae, giving rise to a fundamentally artificial subdivision.
They can be follicles, nuts, achenes and accessory fruits, like the pome of an apple, or the hip of a rose. Many fruits of the family are edible, but their seeds contain amygdalin, which can release cyanide during digestion if the seed is damaged. Identified clades include
Gymnosporangium juniperi-virginianae
Gymnosporangium juniperi-virginianae is a plant pathogen that causes cedar-apple rust. In any location where apples or crabapples and Eastern red-cedar coexist, cedar apple rust can be a destructive or disfiguring disease on both the apples and cedars. Quince and hawthorn are the most common host and many species of juniper can substitute for the Eastern red cedars. On the apple tree, the infections occur on leaves and young twigs; the brightly colored spots produced on the leaves make it easy to identify. Small, pale yellow spots appear on the upper surfaces of the leaves during late April or May on the eastern seaboard of the United States; these spots enlarge and turn orange or red and may show concentric rings of color. Drops of orange liquid may be visible on the spots. In the season, black dots appear on the orange spots on the upper leaf surface. In late summer, tube-like structures develop on the undersurface of the apple leaf. Infected leaves sometimes drop prematurely during drought conditions or when the tree is under additional stress.
Infections on fruit are near the blossom end and are somewhat similar to the leaf lesions. On the Eastern Red Cedar host, the fungus produces reddish-brown galls from 1⁄4–1 inch in diameter; these galls can be mistaken for cone structures by the uninitiated. After reaching a diameter of about 1⁄2 inch, they show many small circular depressions. In the center of each depression is a pimple-like structure. In the spring these structures elongate into orange gelatinous horns; the spore-bearing horns swell during rainy periods in May. The wind carries the microscopic spores to infect apple leaves and young twigs on trees within a radius of several miles of the infected tree. On other species of juniper more common in landscaping and bonsai, the sizes of the infections are reduced. Early in the infection, the galls are small bumps on the woody portions of the plant, they maintain the orange gelatinous form after the first warm rains of spring but on a reduced scale. Understanding of the disease cycle of this rust fungus is necessary for proper identification and control.
Cedar apple rust is caused by the fungi Gymnosporangium or more Gymnosporangium juniperi-virginianae that spend part of their life cycles on Eastern Red Cedars growing near orchards. The complex disease cycle of cedar apple rust, alternating between two host plants, was first delineated by Anders Sandøe Ørsted. On the eastern seaboard of the United States, at the first warm rain of spring, the spore horns become gelatinous masses and produce their teliospores. Wind carries the spores to apple leaves at about the time that apple buds are in the pink or early blossom stage. Upon reaching apple buds or leaves, the spores attach themselves to the young leaves and enter the leaf or fruit tissues. Infection takes place in as little as four hours under favorable conditions. Yellow lesions develop in one to three weeks. In July and August, spores from the apple leaves are produced; the wind carries the spores back to Eastern Red Cedars. The spores land on cedar needle bases or in cracks or crevices of twigs.
There, they produce small, green-brown swellings about the size of a pea. Galls do not produce spores until the second spring. However, mature galls are present every year; this fungus produces four out of five of the spores known to be produced by the class Urediniomycetes during its life cycle. Rust fungi have a complicated life-cycle with up to five types of spores in its life cycle and an alternate host, an "alternate alternate host" as well. Basidiomycetes that have all 5 spore stages and those with less are said to be "macrocyclic" or "microcyclic" respectively; because apples are an economically important crop, control is focused there. Interruption of the disease cycle is the only effective method for control of the cedar apple rust; the recommended method of control is to “remove cedars located within a 1 mile radius” of the apples to interrupt the disease cycle, though this method is practical. For those doing bonsai, it is common to have the trees within feet of each other and on the central eastern seaboard of the United States, Eastern Red Cedar is a common first-growth conifer along roadsides.
There are differences in the susceptibility of various apple varieties.'Jonathan','Rome Beauty','Wealthy' and'York Imperial' are susceptible.'Grimes Golden','Narragansett','Red Delicious','Winesap','Staymans','Redfree','Jonafree' and'Priscilla' are resistant. Crabapples are more susceptible than apples. Resistant crabapples include'Adams','Beverly','Candied Apple','Dolgo','Donald Wyman','Eleyi','Inglis','Indian Summer','Liset','Mt. Arbor', M. persicifolia,'Red Jewel','Robinson','Robusta','Royalty', M. sargentii,'Tina','Snowdrift', and'Special Radiant'. Resistant Crataegus include C. crus-galli, series Intricatae, C. laevigata,'Autumn Glory', C. phaenopyrum, C. pruinosa, C. viridis, and'Winter King'. The resistant varieties are less susceptible to attack, but that does not mean that they are free from an aggressive attack. Fungicide sprays applied in a timely manner are effective against the rust diseases during the apple cycle. Most sprays are applied four times at 7 - starting with pink bud on crabapples.
These applications are to protect the apples from spores being released from the cedar host in mid-spring. If ce
Pucciniomycetes
The Pucciniomycetes are a class of fungi in the Pucciniomycotina subdivision of the Basidiomycota. The class contains 5 orders, 21 families, 190 genera, 8016 species, it includes several important plant pathogens causing forms of fungal rust. Pucciniomycetes develop no basidiocarp, karyogamy occurs in a thick-walled resting spore, meiosis occurs upon germination of teliospore, they have simple septal pores without disc-like spindle pole bodies. Except for a few species, the basidia, when present, are transversally septate. Mannose is the major cell wall carbohydrate, glucose and rhamnose are the less prevalent neutral sugars and xylose is not present
