Meloidogyne incognita

Last updated

Meloidogyne incognita
A juvenile root-knot nematode (Meloidogyne incognita) penetrates a tomato root - USDA-ARS.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Nematoda
Class: Secernentea
Order: Tylenchida
Family: Heteroderidae
Genus: Meloidogyne
Species:
M. incognita
Binomial name
Meloidogyne incognita
(Kofoid & White, 1919)

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.

Contents

M. incognita can move along shallower temperature gradients (0.001 °C/cm) than any other known organism, [1] an example of thermotaxis. The response is complicated and thought to allow the nematodes to move toward an appropriate level in soil, [2] while they search for chemical cues that can guide them to specific roots. [3] [4] [5]

Distribution

Meloidogyne incognita is widely spread around the globe and found in many different soil types. [6]

Host

Meloidogyne incognita is probably the most economically important plant-parasitic nematode species among the tropical and subtropical regions. This nematode is extremely polyphagous, attacking both monocotyledons and dicotyledons. It is estimated that more than 3,000 plant species can be affected. [6] [7] [8] It is a common cause of severe disease in the staple crop cassava (Manihot esculenta). [9] It produces severe galling and thus yield loss. [9]

Symptoms

Plants affected by M. incognita present above ground symptoms of water- and nutrient-stress, yellowing, wilting, and stunting. Below ground galling on roots, bulbs, tubers is the typical symptom. Plant death may occur in high infestation level. [6] [8]

Morphology

Females of M. incognita are pear-shaped with no posterior protuberance. Their stylet ranges from 15 to 16 μm long, and knobs are rounded and offset. Perineal pattern is oval to rounded, typically with high dorsal arch, striae usually wavy, and lateral field absent or weakly demarcated. Males have a not offset head with an elevated labial disc without lateral lips (usually). Their stylet ranges from 23 to 26 μm long, and knobs are rounded to oval and offset. Juveniles' second stage body size ranges from 350 to 450 μm long. Their tail has a rounded tip and ranges from 43 to 65 μm in length with a 6 to 14 μm long hyaline region. [7] [10] [11]

Life cycle

Within the egg, the first molt occurs and a juvenile first state (J1) becomes a juvenile second stage (J2). Under favorable conditions (temperature, moisture, host stimulus) the J2 hatches, reaches and penetrates the host root. Root tips are the primary infection court. Once inside the roots, J2 migrate through cortical tissues towards the vascular zone where they establish a permanent feeding site called giant cell. At this point the nematode enlarges acquire a "sausage" shape and becomes sedentary. Three more molts occur, J2 becomes J3, J4 and then adult. M. incognita is sexually dimorphic. Females acquire a globose shaped body while males become vermiform and leave the roots. Upon maturity females lay eggs into a gelatinous mass that protect them against unfavorable environmental conditions, and the life cycle is repeated. It takes 37 days at 21 °C (70 °F) for M. incognita to complete its life cycle. [7] [10] [11]

Management

Management of M. incognita depends primarily on the crop being affected and relies on multiple strategies such as cultural, biological and chemical control. Among the cultural control crop rotation with nonhost or resistant varieties can be used to keep the nematode population at tolerable levels. Also, usage of organic amendments and antagonistic crops such as Crotalaria spectabilis (Leguminosae) and several Tagetes species (Asteraceae) is effective against this nematode. Some fungi that parasitize eggs, for example Paecilomyces lilacinus , have been using as a biological control. There are several nematicides out in the market for controlling M. incognita. [6] [7] [8]

See also

Related Research Articles

Thermotaxis is a behavior in which an organism directs its locomotion up or down a gradient of temperature.

Northern root-knot nematode 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.

<span class="mw-page-title-main">Root-knot nematode</span> Genus of parasitic worms

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 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.

<i>Radopholus similis</i> Species of roundworm

Radopholus similis is a species of nematode known commonly as the burrowing nematode. It is a parasite of plants, and it is a pest of many agricultural crops. It is an especially important pest of bananas, and it can be found on coconut, avocado, coffee, sugarcane, other grasses, and ornamentals. It is a migratory endoparasite of roots, causing lesions that form cankers. Infected plants experience malnutrition.

Belonolaimus longicaudatus is a common parasite of grasses and other plant crops and products. It is the most destructive nematode pest of turf grass, and it also attacks a wide range of fruit, vegetable, and fiber crops such as citrus, cotton, ornamentals, and forage. The sting nematode is a migratory ectoparasite of roots. It is well established in many golf courses and presents a problem in turf management. The sting nematode is only present in very sandy soils. It cannot reproduce in heavier or clay soils.

<i>Rotylenchulus reniformis</i> Species of roundworm

Rotylenchulus reniformis, the reniform nematode, is a species of parasitic nematode of plants with a worldwide distribution in the tropical and subtropical regions.

<i>Meloidogyne arenaria</i> Species of roundworm

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. Among the several Meloidogyne species that have been characterized, M. arenaria is the most variable both morphologically and cytologically. In 1949, two races of this nematode had been identified, race 1 which reproduces on peanut and race 2 which cannot do so. However, in a recent study, three races were described. López-Pérez et al (2011) had also studied populations of M. arenaria race 2, which reproduces on tomato plants carrying the Mi gene and race 3, which reproduces on both resistant pepper and tomato.

<i>Meloidogyne javanica</i> Species of roundworm

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).

<i>Meloidogyne chitwoodi</i> Species of roundworm

Meloidogyne chitwoodi is a plant pathogenic root-knot nematode that is a crop pest of potatoes, carrots, and black salsify. Root-knot nematodes such as M. chitwoodi cause the production of root-knot galls when their larvae infect the plant's roots and capture nutrients stored in the roots.

Anguina tritici is a plant pathogenic nematode.

Hirschmanniella oryzae, i.e. rice root nematode (RRN), is among the major pests of rice and is the most common plant-parasitic nematode found on irrigated rice. Recent modifications in cultivation practices have led to a substantial increase in rice production, which has been accompanied by heightened levels of RRN. The proportional increases in RRN with rice production can be explained by the nematode's impeccable adaptation towards constantly flooded conditions in which irrigated rice is often being grown.

Meloidogyne brevicauda is a plant-parasitic nematode. It is also called tea root-knot nematode, mature tea nematode or Indian root-knot nematode. It is a member of the root-knot nematodes, which was identified by C. A. Loos in 1953 in Sri Lanka.

There are many plant-parasitic species in the root-knot nematode genus (Meloidogyne) that attack coffee such as M. incognita, M. arenaria, M. exigua, M. javanica and M. coffeicola. Study has already shown interspecific variability coffee, in which show how this species can be adapting to new hosts and environments.

<i>Anguina agrostis</i> Species of roundworm

Anguina agrostis is a plant pathogenic nematode.

Heterodera sacchari, the sugarcane cyst nematode, mitotic parthenogenic sedentary endoparasitic nematode. This plant-parasitic nematode infects the roots of sugarcane, and the female nematode eventually becomes a thick-walled cyst filled with eggs. Aboveground symptoms are species specific and are similar to those caused by other Heterodera species. Symptoms include: stunted and chlorotic plants, and reduced root growth. Seedlings may be killed in heavily infested soils.

<i>Pratylenchus</i> Genus of roundworms

Pratylenchus is a genus of nematodes known commonly as lesion nematodes. They are parasitic on plants and are responsible for root lesion disease on many taxa of host plants in temperate regions around the world. Lesion nematodes are migratory endoparasites that feed and reproduce in the root and move around, unlike the cyst or root-knot nematodes, which may stay in one place. They usually only feed on the cortex of the root. Species are distinguished primarily by the morphology of the stylets.

<i>Meloidogyne enterolobii</i> Species of tree

Meloidogyne enterolobii was originally described from a population collected from the pacara earpod tree in China in 1983. In 2001 it was reported for the first time in the continental USA in Florida. M. enterolobii is now considered one of the most important root-knot nematode species because of its ability of reproducing on root-knot nematode-resistant bell pepper and other economically important crops.

<i>Purpureocillium lilacinum</i> Species of fungus

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 8 to 38 °C for a few isolates, with optimal growth in the range 26 to 30 °C. 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.

Pratylenchus alleni is a migratory endoparasitic nematode, living inside of plant roots and feeding on parenchyma cells in the root cortex. P. alleni is an obligate biotroph, meaning it must have a living host in order to survive. Due to their incredibly broad host range, Pratylenchus species fall third in total economic impact, finishing just behind cyst nematodes and root knot nematodes (Meloidogyne). In Canada, it was isolated for the first time in 2011 in a soybean field.

Mononchoides fortidens, of the order Diplogasterida, is a free-living predacious nematode that feeds on both nematodes and bacteria . The predatory behavior of this nematode presents the opportunity to use it as a bio-control agent against other plant parasitic nematodes. It has been shown to have a preference for the second stage juveniles of Meloidogyne incognita.

References

  1. ↑ Pline, Diez, and Dusenbery, J. Nematology, 20:605-608 (1988). Extremely sensitive thermotaxis of the nematode Meloidogyne incognita.
  2. ↑ Dusenbery, D.B. Biological Cybernetics, 60:431-437 (1989). A simple animal can use a complex stimulus pattern to find a location.
  3. ↑ Pline and Dusenbery. 1987. Responses of the plant-parasitic nematode Meloidogyne incognita to carbon dioxide determined by video camera-computer tracking. Journal of Chemical Ecology. 13 : 873-888.
  4. ↑ Dusenbery. 1987. The theoretical range over which bacteria and nematodes locate plant roots using carbon dioxide. Journal of Chemical Ecology. 13 : 1617-1624.
  5. ↑ Diez and Dusenbery. 1989. Repellent of root-knot nematodes from the exudate of host roots. Journal of Chemical Ecology. 15:2445-2455.
  6. 1 2 3 4 Centre for Agriculture and Bioscience International (CABI). "Meloidogyne incognita (root-knot nematode)".
  7. 1 2 3 4 Perry, R.N.; Starr, J.L. (2009). Root-Knot Nematodes. London: Centre for Agriculture and Bioscience International (CABI). ISBN   9781845934927.
  8. 1 2 3 Gasparin, Ruben. "Root-Knot Nematode".
  9. 1 2
  10. 1 2 Sasser, J.N.; Carter, C.C. (1985). An Advanced Treatise on Meloidogyne. Vol. 1. Raleigh: North Carolina State University Graphics. ISBN   0931901014.
  11. 1 2 Perry, R.N.; Moens, Maurice (2013). Plant Nematology. Centre for Agriculture and Bioscience International (CABI). ISBN   9781780641515.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.