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Xylella
''Xylella fastidiosa'' is an aerobic, Gram-negative bacterium, Gram-negative bacterium of the genus ''Xylella''. It is a plant pathogen, that grows in the water transport tissues of plants (Xylem, xylem vessels) and is transmitted exclusively by xylem sap-feeding insects such as Sharpshooter (insect), sharpshooters and Aphrophoridae, spittlebugs. Many plant diseases are due to infections of ''X. fastidiosa'', including bacterial leaf scorch, oleander leaf scorch, coffee leaf scorch (CLS), alfalfa dwarf, phony peach disease, and the economically important Pierce's disease of grapes (PD), olive quick decline syndrome (OQDS), and citrus variegated chlorosis (CVC). While the largest outbreaks of ''X. fastidiosa''–related diseases have occurred in the Americas and Europe, this pathogen has also been found in Taiwan, Israel, and a few other countries worldwide. ''Xylella fastidiosa'' can infect an extremely wide range of plants, many of which do not show any symptoms of disease. Dise ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xylella
''Xylella fastidiosa'' is an aerobic, Gram-negative bacterium, Gram-negative bacterium of the genus ''Xylella''. It is a plant pathogen, that grows in the water transport tissues of plants (Xylem, xylem vessels) and is transmitted exclusively by xylem sap-feeding insects such as Sharpshooter (insect), sharpshooters and Aphrophoridae, spittlebugs. Many plant diseases are due to infections of ''X. fastidiosa'', including bacterial leaf scorch, oleander leaf scorch, coffee leaf scorch (CLS), alfalfa dwarf, phony peach disease, and the economically important Pierce's disease of grapes (PD), olive quick decline syndrome (OQDS), and citrus variegated chlorosis (CVC). While the largest outbreaks of ''X. fastidiosa''–related diseases have occurred in the Americas and Europe, this pathogen has also been found in Taiwan, Israel, and a few other countries worldwide. ''Xylella fastidiosa'' can infect an extremely wide range of plants, many of which do not show any symptoms of disease. Dise ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olive Quick Decline Syndrome
Olive quick decline syndrome (OQDS) (in Italian: ''Complesso da Disseccamento Rapido dell'Olivo'', CDRO or CoDiRo) is a wasting disease of olive trees which causes wikt:dieback, dieback of the leaves, twigs and branches so that the trees no longer produce crops of olives. The main cause is a strain of the bacterium, ''Xylella fastidiosa'', which is spread by plant-sucking insects such as the meadow froghopper. The bacteria restrict the flow of sap within the tree and so choke its extremities. __TOC__ Impact The disease particularly affects olive groves in Southern Italy. It was first detected in Italy in 2013, in the Salento, Salento Peninsula; by late 2013, it was estimated that approximately 8,000 hectares were affected. As of 2020, the disease was threatening olive groves and oil production in Italy, Greece, and Spain, which together account for 95% of European oil production. One 2020 model predicts a potential economic impact of the disease for Italy over 50 years betwee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xanthomonadales
The Xanthomonadales are a bacterial order within the Gammaproteobacteria. They are one of the largest groups of bacterial phytopathogens, harbouring species such as ''Xanthomonas citri'', ''Xanthomonas euvesicatoria'', ''Xanthomonas oryzae'' and ''Xylella fastidiosa''. These bacteria affect agriculturally important plants including tomatoes, bananas, citrus plants, rice, and coffee. Many species within the order are also human pathogens. Species within the genus ''Stenotrophomonas'' are multidrug resistant opportunistic pathogens that are responsible for nosocomial infections in immunodeficient patients. Characteristics The Xanthomonadales are gram-negative, catalase positive, non-spore forming obligate aerobes.Saddler GS, Bradbury JF (2005) Order III. Xanthomonadales ord. nov. In: Bergey’s Manual of Systematic Bacteriology. pp. 63-122. Eds Brenner DJ, Krieg NR, Staley JT, Garrity GM, Boone, Vos P, Goodfellow M, Rainey FA, Schleifer K-H Springer-: Austin. Members belonging to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xanthomonadaceae
Xanthomonadaceae is a family of Pseudomonadota within the Xanthomonadales The Xanthomonadales are a bacterial order within the Gammaproteobacteria. They are one of the largest groups of bacterial phytopathogens, harbouring species such as ''Xanthomonas citri'', '' Xanthomonas euvesicatoria'', ''Xanthomonas oryzae'' a ... order. It was previously known as Lysobacteraceae. References External links National J.P. Euzéby: List of Prokaryotic names with Standing in Nomenclature (LPSN) {{gammaproteobacteria-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacterial Leaf Scorch
Bacterial leaf scorch (commonly abbreviated BLS, also called bacterial leaf spot) is a disease state affecting many crops, caused mainly by the xylem-plugging bacterium ''Xylella fastidiosa''. It can be mistaken for ordinary ''leaf scorch'' caused by cultural practices such as over-fertilization. Hosts BLS can be found on a wide variety of hosts, ranging from ornamental trees (elm, maple, oak) and shrubs, to crop species including blueberry and almond. Bacterial spot of peppers and tomatoes Bacterial spot of peppers and tomatoes is caused by the bacteria ''Xanthomonas campestris'' pv. ''vesicatoria''. Bacterial spot of peaches Bacterial spot of peaches is caused by the bacteria ''Xanthomonas campestris'' pv. ''pruni''. Spots may form on the leaves and they can be mistaken for ''peach scab'', which is caused by a fungus. Bacterial spot of pecans Symptoms An irregular browning leaf margin which may or may not be bordered by a pale halo.http://www.usna.usda.gov/Rese ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sharpshooter (insect)
The name sharpshooter is used to refer to any of various genera and species of large leafhoppers in the tribe Proconiini of the family Cicadellidae. As with all cicadellids, they have piercing-sucking mouthparts and closely spaced rows of fine spines on their hind legs. The nymphs feed by inserting their needle-like mouthparts into the xylem of the small stems on the plant where the eggs were deposited; the adults have wings and are highly mobile, and most feed on a variety of different plant species. Both nymphs and adults filter a huge volume of dilute liquid through their digestive system to extract the trace nutrients, and much of the water and carbohydrates are squirted forcibly away from the body in a fine stream of droplets, thus earning them their common name. This group includes a few species which are plant pests, the most serious of which is ''Homalodisca vitripennis'' (the "Glassy-winged sharpshooter"). A microbial plant parasite, ''Xylella fastidiosa'', is carried b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gammaproteobacteria
Gammaproteobacteria is a class of bacteria in the phylum Pseudomonadota (synonym Proteobacteria). It contains about 250 genera, which makes it the most genera-rich taxon of the Prokaryotes. Several medically, ecologically, and scientifically important groups of bacteria belong to this class. It is composed by all Gram-negative microbes and is the most phylogenetically and physiologically diverse class of Proteobacteria. These microorganisms can live in several terrestrial and marine environments, in which they play various important roles, including ''extreme environments'' such as hydrothermal vents. They generally have different shapes - rods, curved rods, cocci, spirilla, and filaments and include free living bacteria, biofilm formers, commensals and symbionts, some also have the distinctive trait of being bioluminescent. Metabolisms found in the different genera are very different; there are both aerobic and anaerobic (obligate or facultative) species, chemolithoautotrophic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gram-negative Bacterium
Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wall sandwiched between an inner cytoplasmic cell membrane and a bacterial outer membrane. Gram-negative bacteria are found in virtually all environments on Earth that support life. The gram-negative bacteria include the model organism ''Escherichia coli'', as well as many pathogenic bacteria, such as ''Pseudomonas aeruginosa'', ''Chlamydia trachomatis'', and ''Yersinia pestis''. They are a significant medical challenge as their outer membrane protects them from many antibiotics (including penicillin), detergents that would normally damage the inner cell membrane, and lysozyme, an antimicrobial enzyme produced by animals that forms part of the innate immune system. Additionally, the outer leaflet of this membrane comprises a complex lipo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biofilm
A biofilm comprises any syntrophic consortium of microorganisms in which cells stick to each other and often also to a surface. These adherent cells become embedded within a slimy extracellular matrix that is composed of extracellular polymeric substances (EPSs). The cells within the biofilm produce the EPS components, which are typically a polymeric conglomeration of extracellular polysaccharides, proteins, lipids and DNA. Because they have three-dimensional structure and represent a community lifestyle for microorganisms, they have been metaphorically described as "cities for microbes". Biofilms may form on living or non-living surfaces and can be prevalent in natural, industrial, and hospital settings. They may constitute a microbiome or be a portion of it. The microbial cells growing in a biofilm are physiologically distinct from planktonic cells of the same organism, which, by contrast, are single cells that may float or swim in a liquid medium. Biofilms can form ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drupe
In botany, a drupe (or stone fruit) is an indehiscent fruit in which an outer fleshy part (exocarp, or skin, and mesocarp, or flesh) surrounds a single shell (the ''pit'', ''stone'', or '' pyrena'') of hardened endocarp with a seed (''kernel'') inside. These fruits usually develop from a single carpel, and mostly from flowers with superior ovaries (polypyrenous drupes are exceptions). The definitive characteristic of a drupe is that the hard, lignified stone is derived from the ovary wall of the flower. In an aggregate fruit, which is composed of small, individual drupes (such as a raspberry), each individual is termed a drupelet, and may together form an aggregate fruit. Such fruits are often termed ''berries'', although botanists use a different definition of ''berry''. Other fleshy fruits may have a stony enclosure that comes from the seed coat surrounding the seed, but such fruits are not drupes. Flowering plants that produce drupes include coffee, jujube, mango, oli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grafting
Grafting or graftage is a horticultural technique whereby tissues of plants are joined so as to continue their growth together. The upper part of the combined plant is called the scion () while the lower part is called the rootstock. The success of this joining requires that the vascular tissues grow together and such joining is called inosculation. The technique is most commonly used in asexual propagation of commercially grown plants for the horticultural and agricultural trades. In most cases, one plant is selected for its roots and this is called the stock or rootstock. The other plant is selected for its stems, leaves, flowers, or fruits and is called the scion or cion. The scion contains the desired genes to be duplicated in future production by the stock/scion plant. In stem grafting, a common grafting method, a shoot of a selected, desired plant cultivar is grafted onto the stock of another type. In another common form called bud grafting, a dormant side bud is gra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seed
A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiosperm plants. Seeds are the product of the ripened ovule, after the embryo sac is fertilized by sperm from pollen, forming a zygote. The embryo within a seed develops from the zygote, and grows within the mother plant to a certain size before growth is halted. The seed coat arises from the integuments of the ovule. Seeds have been an important development in the reproduction and success of vegetable gymnosperm and angiosperm plants, relative to more primitive plants such as ferns, mosses and liverworts, which do not have seeds and use water-dependent means to propagate themselves. Seed plants now dominate biological niches on land, from forests to grasslands both in hot and cold climates. The term "seed" also has a general me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
