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Hemileia Vastatrix
''Hemileia vastatrix'' is a multicellular basidiomycete fungus of the order Pucciniales (previously also known as Uredinales) that causes coffee leaf rust (CLR), a disease affecting the coffee plant. Coffee serves as the obligate host of coffee rust, that is, the rust must have access to and come into physical contact with coffee ('' Coffea sp.'') in order to survive. CLR is one of the most economically important diseases of coffee, worldwide. Previous epidemics have destroyed coffee production of entire countries. In more recent history, an epidemic in Central America in 2012 reduced the region's coffee output by 16%. The primary pathological mechanism of the fungus is a reduction in the plant's ability to derive energy through photosynthesis by covering the leaves with fungus spores and/or causing leaves to drop from the plant. The reduction in photosynthetic ability (plant's metabolism) results in a reduction in quantity and quality of flower and fruit production, whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coffee Rust
''Hemileia vastatrix'' is a multicellular Basidiomycota, basidiomycete fungus of the order Pucciniales (previously also known as Uredinales) that causes coffee leaf rust (CLR), a disease affecting the Coffea, coffee plant. Coffee serves as the obligate host (biology), host of coffee rust, that is, the rust must have access to and come into physical contact with coffee (''Coffea sp.'') in order to survive. CLR is one of the most economically important diseases of coffee, worldwide. Previous epidemics have destroyed coffee production of entire countries. In more recent history, an epidemic in Central America in 2012 reduced the region's coffee output by 16%. The primary pathological mechanism of the fungus is a reduction in the plant's ability to derive energy through photosynthesis by covering the leaves with fungus spores and/or causing leaves to drop from the plant. The reduction in photosynthetic ability (plant's metabolism) results in a reduction in quantity and quality o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telium
Telium, plural telia, are structures produced by Rust (fungus), rust fungi as part of the reproductive cycle. They are typically yellow or orange drying to brown or black and are exclusively a mechanism for the release of teliospores which are released by wind or water to infect the alternate Host (biology), host in the rust life-cycle. The telial stage provides an overwintering strategy in the life cycle of a parasitic heteroecious fungus by producing teliospores; this occurs on cedar trees. A primary aecial stage is spent parasitizing a separate host plant which is a precursor in the life cycle of heteroecious fungi. Teliospores are released from the telia in the spring. The spores can spread many kilometers through the air, however most are spread near the host plant. Host plants There are a number of plants that can be infected by the telial stage. Therefore, the telial stage is considered a pathogen to those plants. A few specific plant pathogenic species are listed here with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual Reproduction
Sexual reproduction is a type of reproduction that involves a complex life cycle in which a gamete ( haploid reproductive cells, such as a sperm or egg cell) with a single set of chromosomes combines with another gamete to produce a zygote that develops into an organism composed of cells with two sets of chromosomes ( diploid). This is typical in animals, though the number of chromosome sets and how that number changes in sexual reproduction varies, especially among plants, fungi, and other eukaryotes. In placental mammals, sperm cells exit the penis through the male urethra and enter the vagina during copulation, while egg cells enter the uterus through the oviduct. Other vertebrates of both sexes possess a cloaca for the release of sperm or egg cells. Sexual reproduction is the most common life cycle in multicellular eukaryotes, such as animals, fungi and plants. Sexual reproduction also occurs in some unicellular eukaryotes. Sexual reproduction does not occur in pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meiosis
Meiosis () is a special type of cell division of germ cells in sexually-reproducing organisms that produces the gametes, the sperm or egg cells. It involves two rounds of division that ultimately result in four cells, each with only one copy of each chromosome (haploid). Additionally, prior to the division, genetic material from the paternal and maternal copies of each chromosome is crossed over, creating new combinations of code on each chromosome. Later on, during fertilisation, the haploid cells produced by meiosis from a male and a female will fuse to create a zygote, a cell with two copies of each chromosome. Errors in meiosis resulting in aneuploidy (an abnormal number of chromosomes) are the leading known cause of miscarriage and the most frequent genetic cause of developmental disabilities. In meiosis, DNA replication is followed by two rounds of cell division to produce four daughter cells, each with half the number of chromosomes as the original parent cell. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autoecious
A heteroecious parasite is one that requires at least two Host (biology), hosts. The ''primary host'' is the host in which the parasite spends its adult life; the other is the ''secondary host''. Both hosts are required for the parasite to complete its life cycle. This can be contrasted with an autoecious parasite which can complete its life cycle on a single host species. Many rust fungi have heteroecious life cycles: In parasitology, heteroxeny, or heteroxenous development, is a synonymous term that characterizes a parasite whose development involves several Host (biology), hosts. Fungal examples * ''Gymnosporangium'' (Cedar-apple rust): the juniper is the primary (teliospore, telial) host and the apple, pear or Crataegus, hawthorn is the secondary (aecial) host. * ''White Pine Blister Rust, Cronartium ribicola'' (White pine blister rust): the primary host are Pinus classification, white pines, and Ribes, currants the secondary. * ''Hemileia vastatrix'' (Coffee rust): the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heteroecious
A heteroecious parasite is one that requires at least two hosts. The ''primary host'' is the host in which the parasite spends its adult life; the other is the ''secondary host''. Both hosts are required for the parasite to complete its life cycle. This can be contrasted with an autoecious parasite which can complete its life cycle on a single host species. Many rust fungi have heteroecious life cycles: In parasitology, heteroxeny, or heteroxenous development, is a synonymous term that characterizes a parasite whose development involves several hosts. Fungal examples * '' Gymnosporangium'' (Cedar-apple rust): the juniper is the primary ( telial) host and the apple, pear Pears are fruits produced and consumed around the world, growing on a tree and harvested in late summer into mid-autumn. The pear tree and shrub are a species of genus ''Pyrus'' , in the Family (biology), family Rosaceae, bearing the Pome, po ... or hawthorn is the secondary ( aecial) host. * '' C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Substomatal Cavity
In plants, the substomatal cavity is the cavity located immediately proximal to the stoma. It acts as a diffusion chamber connected with intercellular air spaces and allows rapid diffusion of carbon dioxide and other gases (such as plant pheromones) in and out of plant cells. References Graham LE, Graham JM, Wilcox LW (2006) Plant Biology (Second Edition). Pearsons Education, USA. See also *Stoma In botany, a stoma (: stomata, from Greek language, Greek ''στόμα'', "mouth"), also called a stomate (: stomates), is a pore found in the Epidermis (botany), epidermis of leaves, stems, and other organs, that controls the rate of gas exc ... * Transpiration stream Plant cells Plant anatomy {{botany-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Appressorium
An appressorium is a specialized cell typical of many fungal plant pathogens that is used to infect host plants. It is a flattened, hyphal "pressing" organ, from which a minute infection peg grows and enters the host, using turgor pressure capable of punching through even Mylar. Following spore attachment and germination on the host surface, the emerging germ tube perceives physical cues such as surface hardness and hydrophobicity, as well as chemical signals including wax monomers that trigger appressorium formation. Appressorium formation begins when the tip of the germ tube ceases polar growth, hooks, and begins to swell. The contents of the spore are then mobilized into the developing appressorium, a septum develops at the neck of the appressorium, and the germ tube and spore collapse and die. As the appressorium matures, it becomes firmly attached to the plant surface and a dense layer of melanin is laid down in the appressorium wall, except across a pore at the plant interfac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spore
In biology, a spore is a unit of sexual reproduction, sexual (in fungi) or asexual reproduction that may be adapted for biological dispersal, dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the Biological life cycle, life cycles of many plants, algae, fungus, fungi and protozoa. They were thought to have appeared as early as the mid-late Ordovician period as an adaptation of early land plants. Bacterial spores are not part of a sexual cycle, but are resistant structures used for survival under unfavourable conditions. Myxozoan spores release amoeboid infectious germs ("amoebulae") into their hosts for parasitic infection, but also reproduce within the hosts through the pairing of two nuclei within the plasmodium, which develops from the amoebula. In plants, spores are usually haploid and unicellular and are produced by meiosis in the sporangium of a diploid sporophyte. In some rare cases, a diploid spore is also p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Germ Pore
A germ pore is a small pore in the outer wall of a fungal spore through which the germ tube exits upon germination. It can be wikt:apical, apical or eccentric in its location, and, on light microscopy, may be visualized as a lighter coloured area on the cell wall. Apical germ pore is mushroom spore which has a pore at one end. Some spores have a hole in the cell wall where the first strand of germinating mycelium emerges. If the cell wall is divided from one end to the other, this is called a germ slit. Commonly the germ pore is at one end of the mushroom spore and is called an apical pore. Mushroom genera with apical germ pores include ''Agrocybe'', ''Panaeolus'', ''Psilocybe'', and ''Pholiota''. See also *mycelium *spore External linksIMA Mycological Glossary: Germ pore Fungal morphology and anatomy {{mycology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biological Life Cycle
In biology, a biological life cycle (or just life cycle when the biological context is clear) is a series of stages of the life of an organism, that begins as a zygote, often in an egg, and concludes as an adult that reproduces, producing an offspring in the form of a new zygote which then itself goes through the same series of stages, the process repeating in a cyclic fashion. "The concept is closely related to those of the life history, Developmental biology, development and ontogeny, but differs from them in stressing renewal." Transitions of form may involve growth, asexual reproduction, or sexual reproduction. In some organisms, different "generations" of the species succeed each other during the life cycle. For Embryophyte, plants and many algae, there are two multicellular stages, and the life cycle is referred to as alternation of generations. The term life history is often used, particularly for organisms such as the red algae which have three multicellular stages (or mor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aecium
An aecium (plural aecia) is a specialised reproductive structure found in some plant pathogenic rust fungi that produce aeciospores. Aecia may also be referred to as "cluster cups". The term aecidium (plural aecidia) is used interchangeably but is not preferred. In some rust fungi such as '' Phragmidium'', aecia lack an outer wall structure (a peridium The peridium is the protective layer that encloses a mass of spores in fungi. This outer covering is a distinctive feature of gasteroid fungi. Description Depending on the species, the peridium may vary from being paper-thin to thick and rubb ...) but instead produce a diffuse aecium called a caeoma.''Fungi''. Lilian E Hawker, 1966, Hutchinson University Library In some species of rust fungi with a life cycle including two different host plants, the binucleate spores produced in the aecia cannot infect the current plant host, but must infect a different plant species. References Fungal morphology and anatomy Reprod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
