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Glossary Of Phytopathology
This is a glossary of some of the terms used in phytopathology. Phytopathology is the study of plant diseases. It is a multi-disciplinary science since prerequisites for disease development are the presence of a susceptible host species, a pathogen and the appropriate environmental conditions. This is known as the disease triangle. Because of this interaction, the terminology used in phytopathology often comes from other disciplines including those dealing with the host species ( botany / plant science, plant physiology), the pathogen (bacteriology, mycology, nematology, virology), the environment and disease management practices (agronomy, soil science, meteorology, environmental science, ecology, plant breeding, pesticides, entomology), and areas of study that apply to both the host and pathogen (molecular biology, genetics, molecular genetics). The result is that most phytopathological glossary include terms from these other disciplines in addition to terms ( disease inci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phytopathology
Plant pathology or phytopathology is the scientific study of plant diseases caused by pathogens (infectious organisms) and environmental conditions (physiological factors). Plant pathology involves the study of pathogen identification, disease etiology, disease cycles, economic impact, plant disease epidemiology, plant disease resistance, how plant diseases affect humans and animals, pathosystem genetics, and management of plant diseases. Plant pathogenicity Plant pathogens, organisms that cause infectious plant diseases, include fungus, fungi, oomycetes, bacterium, bacteria, plant virus, viruses, viroids, virus-like organisms, phytoplasmas, protozoa, nematodes and parasitic plants. In most plant pathosystems, virulence depends on hydrolases and enzymes that degrade the cell wall. The vast majority of these act on pectins (for example, pectinesterase, pectate lyase, and pectinases). For microbes, the cell wall polysaccharides are both a food source and a barrier to be over ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetics
Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinians, Augustinian friar working in the 19th century in Brno, was the first to study genetics scientifically. Mendel studied "trait inheritance", patterns in the way traits are handed down from parents to offspring over time. He observed that organisms (pea plants) inherit traits by way of discrete "units of inheritance". This term, still used today, is a somewhat ambiguous definition of what is referred to as a gene. Phenotypic trait, Trait inheritance and Molecular genetics, molecular inheritance mechanisms of genes are still primary principles of genetics in the 21st century, but modern genetics has expanded to study the function and behavior of genes. Gene structure and function, variation, and distribution are studied within the context of the Cell (bi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diploid
Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Here ''sets of chromosomes'' refers to the number of maternal and paternal chromosome copies, respectively, in each homologous chromosome pair—the form in which chromosomes naturally exist. Somatic cells, tissues, and individual organisms can be described according to the number of sets of chromosomes present (the "ploidy level"): monoploid (1 set), diploid (2 sets), triploid (3 sets), tetraploid (4 sets), pentaploid (5 sets), hexaploid (6 sets), heptaploid or septaploid (7 sets), etc. The generic term polyploid is often used to describe cells with three or more sets of chromosomes. Virtually all sexually reproducing organisms are made up of somatic cells that are diploid or greater, but ploidy level may vary widely between different organisms, between different tissues within the same organism, and at different stages in a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlamydospore
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 conditions, such as dry or hot seasons. '' Fusarium oxysporum'' which causes the plant disease Fusarium wilt is one which forms chlamydospores in response to stresses like nutrient depletion. Mycelia of the pathogen can survive in this manner and germinate in favorable conditions. Chlamydospores are usually dark-coloured, spherical, and have a smooth (non-ornamented) surface. They are multicellular, with cells connected by pores in the septae between cells. Chlamydospores are a result of asexual reproduction (in which case they are conidia called chlamydoconidia) or sexual reproduction (rare). Teliospores are special kind of chlamydospores formed by rusts and smuts. File:Candida pseudohyphae, chlamydospores, blastospores.png, Ps ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basidiomycetes
Basidiomycota () is one of two large division (mycology), divisions that, together with the Ascomycota, constitute the subkingdom Dikarya (often referred to as the "higher fungi") within the kingdom Fungi. Members are known as basidiomycetes. More specifically, Basidiomycota includes these groups: agarics, puffballs, Phallaceae, stinkhorns, Bracket fungus, bracket fungi, other polypores, Jelly fungus, jelly fungi, boletes, Cantharellus, chanterelles, Geastraceae, earth stars, Smut (fungus), smuts, Common bunt, bunts, Rust (fungus), rusts, Sporobolomyces, mirror yeasts, and ''Cryptococcus (fungus), Cryptococcus'', the human pathogenic yeast. Basidiomycota are filamentous fungi composed of hyphae (except for Yeast, basidiomycota-yeast) and reproduce sexually via the formation of specialized club-shaped end Cell (biology), cells called Basidium, basidia that normally bear external Meiosis, meiospores (usually four). These specialized spores are called basidiospores. However, some Bas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ascogonium
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Ascocarp
An ascocarp, or ascoma (: ascomata), is the fruiting body ( sporocarp) of an ascomycete phylum fungus. It consists of very tightly interwoven hyphae and millions of embedded 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). Classification The ascocarp is classified according to its placement (in ways not fundamental to the basic taxonomy). It is called ''epigeous'' if it grows above ground, as with the morels, while underground ascocarps, such as truffles, are termed ''hypogeous''. The structure enclosing the hymenium is divided into the types described below (apothecium, cleistothecium, etc.) and this character ''is'' important for the taxonomic classification of the fungus. Apothecia can be relatively large and fleshy, whereas the others are microscopic—about the size of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amphigynous
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Actinomycetota
The Actinomycetota (or Actinobacteria) are a diverse phylum of Gram-positive bacteria with high GC content. They can be terrestrial or aquatic. They are of great importance to land flora because of their contributions to soil systems. In soil they help to decompose the organic matter of dead organisms so the molecules can be taken up anew by plants. While this role is also played by fungi, Actinomycetota are much smaller and likely do not occupy the same ecological niche. In this role the colonies often grow extensive mycelia, as fungi do, and the name of an important order of the phylum, Actinomycetales (the actinomycetes), reflects that they were long believed to be fungi. Some soil actinomycetota (such as '' Frankia'') live symbiotically with the plants whose roots pervade the soil, fixing nitrogen for the plants in exchange for access to some of the plant's saccharides. Other species, such as many members of the genus ''Mycobacterium'', are important pathogens. Beyond th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erumpent
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Acervulus
An acervulus (pl. acervuli) is a small asexual fruiting body that erupts through the epidermis of host plants parasitised by mitosporic fungi of the form order Melanconiales ( Deuteromycota, Coelomycetes). It has the form of a small cushion at the bottom of which short crowded conidiophores are formed. The 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 fo ...s escape through an opening at the top. Sources * Trigiano, Robert Nicholas, Mark Townsend Windham, Alan S. Windham. (2004) ''Plant Pathology: Concepts and Laboratory Exercises.'' CRC Press. pp. 11,129,137. Fungal morphology and anatomy Asexual reproduction {{Plant-morphology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
