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Meloidogyne
Root-knot nematodes are plant-parasitic nematodes from the genus ''Meloidogyne''. They exist in soil in areas with hot climates or short winters. About 2000 species of plants worldwide are susceptible to infection by root-knot nematodes and they cause approximately 5% of global crop loss. Root-knot nematode larvae infect plant roots, causing the development of root-knot galls that drain the plant's photosynthate and nutrients. Infection of young plants may be lethal, while infection of mature plants causes decreased yield. Economic impact Root-knot nematodes (''Meloidogyne'' spp.) are one of the three most economically damaging genera of plant-parasitic nematodes on horticultural and field crops. Root-knot nematodes are distributed worldwide, and are obligate parasites of the roots of thousands of plant species, including monocotyledonous and dicotyledonous, herbaceous and woody plants. The genus includes more than 90 species, with some species having several races. Four ''Meloid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meloidogyne Javanica
''Meloidogyne javanica'' is a species of plant-pathogenic nematodes. It is one of the tropical root-knot nematodes and a major agricultural pest in many countries. It has many hosts. ''Meloidogyne javanica'' reproduces by obligatory mitotic parthenogenesis (apomixis). Hosts ''Meloidogyne javanica'' is a nematode pathogen that affects over 770 species of plants (Cabi 2018). The hosts of this pathogen include both weeds and crops of economic importance. Those of economic importance include tea, grapevine, vegetables, fruit trees, cereals, and ornamentals (Cabi 2018). ''Meloidogyne javanica'' is considered an agricultural pest, as it is extremely abundant and damaging (Alford 2012). Symptoms Because there are so many different hosts for this pathogen, the symptoms are very variable. Common symptoms include abnormal leaf color, abnormal leaf form, wilting leaves, galls, swollen roots, reduced root system, dwarfing and senescence (Cabi 2018). This pathogen does the most damage w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meloidogyne Arenaria
''Meloidogyne arenaria'' is a species of plant pathogenic nematodes. This nematode is also known as the ''peanut root knot nematode''. The word "''Meloidogyne''" is derived from two Greek words that mean "apple-shaped" and "female".. The peanut root knot nematode, ''M. arenaria'' is one of the "major" ''Meloidogyne'' species because of its worldwide economic importance. ''M. arenaria'' is a predominant nematode species in the United States attacking peanut in Alabama, Florida, Georgia, and Texas. The most damaging nematode species for peanut in the USA is ''M. arenaria'' race 1 and losses can exceed 50% in severely infested fields.K. Proite, R. Carneiro R. Falcão, A. Gomes S. Leal-Bertioli P. Guimarães and D. Bertioli, 2008. Post-infection development and histopathology of Meloidogyne arenaria race 1 on Arachis spp. Among the several ''Meloidogyne'' species that have been characterized, ''M. arenaria'' is the most variable both morphologically and cytologically. In 1949, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meloidogyne Incognita
''Meloidogyne incognita'' (root-knot nematode, RKN), also known as the southern root-nematode or cotton root-knot nematode is a plant-parasitic roundworm in the family Heteroderidae. This nematode is one of the four most common species worldwide and has numerous hosts. It typically incites large, usually irregular galls on roots as a result of parasitism. ''M. incognita'' can move along shallower temperature gradients (0.001 °C/cm) than any other known organism, an example of thermotaxis. The response is complicated and thought to allow the nematodes to move toward an appropriate level in soil, while they search for chemical cues that can guide them to specific roots.Diez and Dusenbery. 1989. Repellent of root-knot nematodes from the exudate of host roots. Journal of Chemical Ecology. 15:2445-2455. Distribution ''Meloidogyne incognita'' is widely spread around the globe and found in many different soil types. Host ''Meloidogyne incognita'' is probably the most ec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meloidogyne Hapla
Northern root-knot nematode (''Meloidogyne hapla'') is a species of vegetable pathogens which produces tiny galls on around 550 crop and weed species. They invade root tissue after birth. Females are able to lay up to 1,000 eggs at a time in a large egg mass. By surviving harsh winters, they can survive in cold climates (hence, the name, Northern). Hosts and symptoms ''Meloidogyne hapla'' (Northern root-knot nematode) has a wide host range. It is polyphagous and affects over 550 crops and weeds. It feeds on many agricultural and horticultural plants (vegetables, fruits, ornamentals), but few grasses or cereals. A list of known hosts can be found at the bottom of this page. Symptoms can be seen in the roots, leaves, and the overall growth of the infected plant. In roots, there may be stunting, wilting, and the formation of abnormal growths called galls. Galls are usually small and spherical and are situated near many small roots. They are formed when the nematode enters the ro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pasteuria Penetrans
''Pasteuria'' is a genus of mycelial and endospore-forming, nonmotile gram-positive bacteria that are obligate parasites of some nematodes and crustaceans. The genus of ''Pasteuria'' was previously classified within the family Alicyclobacillaceae, but has since been moved to the family Pasteuriaceae. Steps of infection Animals that are susceptible to ''Pasteuria'' become infected when they are exposed to endospores in soil or water. Therefore, ''Pasteuria'' are transmitted horizontally between hosts and when an infected host dies, it releases spores to the soil or sediment. The likelihood of infections is related to the endospore density in the environment and can be affected by temperature. However, the ability of an endospore to attach to and infect a host is highly specific and following contact with a compatible host, ''the Pasteuria'' endospores are activated, penetrate the host's cuticle, proliferate within the host thereby restricting it from reproducing and ultimatel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paecilomyces Lilacinus
''Purpureocillium lilacinum'' is a species of filamentous fungus in the family Ophiocordycipitaceae. It has been isolated from a wide range of habitats, including cultivated and uncultivated soils, forests, grassland, deserts, estuarine sediments and sewage sludge, and insects. It has also been found in nematode eggs, and occasionally from females of root-knot and cyst nematodes. In addition, it has frequently been detected in the rhizosphere of many crops. The species can grow at a wide range of temperatures – from for a few isolates, with optimal growth in the range . It also has a wide pH tolerance and can grow on a variety of substrates. ''P. lilacinum'' has shown promising results for use as a biocontrol agent to control the growth of destructive root-knot nematodes. Taxonomy and phylogeny The species was originally described by American mycologist Charles Thom in 1910, under than name ''Penicillium lilacinum''. Taxonomic synonyms include ''Penicillium amethysti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cassava
''Manihot esculenta'', common name, commonly called cassava, manioc, or yuca (among numerous regional names), is a woody shrub of the spurge family, Euphorbiaceae, native to South America, from Brazil, Paraguay and parts of the Andes. Although a perennial plant, cassava is extensively cultivated in tropical and subtropical regions as an annual crop for its edible starchy tuberous root. Cassava is predominantly consumed in boiled form, but substantial quantities are processed to extract cassava starch, called tapioca, which is used for food, animal feed, and industrial purposes. The Brazilian , and the related ''garri'' of West Africa, is an edible coarse flour obtained by grating cassava roots, pressing moisture off the obtained grated pulp, and finally drying it (and roasting in the case of both and ''garri''). Cassava is the third-largest source of carbohydrates in food in the tropics, after rice and maize, making it an important staple food, staple; more than 500 million pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gall
Galls (from the Latin , 'oak-apple') or ''cecidia'' (from the Greek , anything gushing out) are a kind of swelling growth on the external tissues of plants. Plant galls are abnormal outgrowths of plant tissues, similar to benign tumors or warts in animals. They can be caused by various parasites, from viruses, fungi and bacteria, to other plants, insects and mites. Plant galls can be such highly organized structures that their cause can be determined without the actual agent being identified. This applies particularly to insect and mite plant galls. The study of plant galls is known as cecidology. Anatomy Shape and size Galls develop on various plant organs, providing nutrition and shelter to inducing insects. Galls display vast variation in morphology, size, and wall composition. The size of insect galls can range significantly, from approximately two inches in diameter to less than one-sixteenth of an inch. Some galls are so small that they are merely slightly thick ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nematode
The nematodes ( or ; ; ), roundworms or eelworms constitute the phylum Nematoda. Species in the phylum inhabit a broad range of environments. Most species are free-living, feeding on microorganisms, but many are parasitic. Parasitic worms (helminths) are the cause of soil-transmitted helminthiases. They are classified along with arthropods, tardigrades and other moulting animals in the clade Ecdysozoa. Unlike the flatworms, nematodes have a tubular digestive system, with openings at both ends. Like tardigrades, they have a reduced number of Hox genes, but their sister phylum Nematomorpha has kept the ancestral protostome Hox genotype, which shows that the reduction has occurred within the nematode phylum. Nematode species can be difficult to distinguish from one another. Consequently, estimates of the number of nematode species are uncertain. A 2013 survey of animal biodiversity suggested there are over 25,000. Estimates of the total number of extant species are su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nematode Nodules
The nematodes ( or ; ; ), roundworms or eelworms constitute the phylum Nematoda. Species in the phylum inhabit a broad range of environments. Most species are free-living, feeding on microorganisms, but many are parasitic. Parasitic worms (helminths) are the cause of soil-transmitted helminthiases. They are classified along with arthropods, tardigrades and other moulting animals in the clade Ecdysozoa. Unlike the flatworms, nematodes have a tubular digestive system, with openings at both ends. Like tardigrades, they have a reduced number of Hox genes, but their sister phylum Nematomorpha has kept the ancestral protostome Hox genotype, which shows that the reduction has occurred within the nematode phylum. Nematode species can be difficult to distinguish from one another. Consequently, estimates of the number of nematode species are uncertain. A 2013 survey of animal biodiversity suggested there are over 25,000. Estimates of the total number of extant species are subject to eve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Juglone
Juglone, also called 5-hydroxy-1,4-naphthalenedione (IUPAC) is a phenolic organic compound with the molecular formula C10H6O3. In the food industry, juglone is also known as C.I. Natural Brown 7 and C.I. 75500. It is insoluble in benzene but soluble in dioxane, from which it crystallizes as yellow needles. It is an isomer of lawsone, which is the active dye compound in the henna leaf. Juglone occurs naturally in the leaves, roots, husks, fruit ( the epicarp), and bark of plants in the Juglandaceae family, particularly the black walnut ('' Juglans nigra''), and is toxic or growth-stunting to many types of plants. It is sometimes used as an herbicide, as a dye for cloth and inks, and as a coloring agent for foods and cosmetics. History The allelopathic effects of walnut trees on other plants were observed as far back as the 1st century CE. Juglone itself was first isolated from black walnut in 1856, and was identified as the compound responsible for its allelopathic effect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
