Meloidogyne arenaria

Last updated

Meloidogyne arenaria
Meloidogyne arenaria at Beta vulgaris (03).jpg
Meloidogyne arenaria on Beta vulgaris (beetroot)
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Nematoda
Class: Secernentea
Order: Tylenchida
Family: Heteroderidae
Genus: Meloidogyne
Species:
M. arenaria
Binomial name
Meloidogyne arenaria
(Neal, 1889)

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". [1] The peanut root knot nematode, M. arenaria is one of the "major" Meloidogyne species because of its worldwide economic importance. [2] M. arenaria is a predominant nematode species in the United States attacking peanut in Alabama, Florida, Georgia, and Texas. [3] The most damaging nematode species for peanut in the USA is M. arenaria race 1 and losses can exceed 50% in severely infested fields. [4] Among the several Meloidogyne species that have been characterized, M. arenaria is the most variable both morphologically and cytologically. [2] In 1949, two races of this nematode had been identified, race 1 which reproduces on peanut and race 2 which cannot do so. [2] However, in a recent study, three races were described (races 1, 2, and 3). [5] 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. [6]

Contents

History

Meloidogyne arenaria has the same history as the other root knot nematodes. Meloidogyne spp were originally grouped together with the cyst nematodes ( Heterodera spp) but they were later separated after they were confirmed to be significantly different from each other. The changes that were made when discovering Meloidogyne spp of nematodes are described below:

Distribution

Crop damage by this nematode is mostly faced in warmer regions and it is rarely found in areas where the average monthly temperatures approach freezing. [2] The peanut root knot nematode, race 1 is found in all areas where peanuts are grown. [8]

Economic importance

The peanut root-knot nematode is the most serious nematode pest of the crop and questionably the most serious soil-borne disease problem. For example, the nematode is present in almost all fields where the crop is grown in Florida and economic damage is estimated to occur in greater than 50% of these fields. Individual peanut fields heavily infested with the root-knot nematode have sustained yield losses greater than 75%. In addition to causing considerable damage alone, it also increases the severity and incidence of other soil-borne diseases such as southern stem rot and Cylindrocladium blackrot. [9] M. arenaria is C-rated pest in California. [7]

Morphology and anatomy

Different development stages of this nematode have unique features that are used to describe them. Among the characters commonly used to define nematode species and populations, morphometric characters have a marked significance. [5]

Females are swollen, pear-shaped pearly white and sedentary. They deposit their eggs in a gelatinous mass, which usually protrudes from galled root tissue. Females of this nematode are completely endoparasitic. [10] Mature females of M. arenaria are identified by the cuticular markings in the perineal area, stylet length, punctations on the cuticle. [7] [10] When describing the morphology of M. arenaria race 1, Eisenback et al. (1981) reported that in females, the dorsal arch is flattened and rounded. The striae in the arch are slightly indented at the lateral lines and generally form a shoulder on the arch. The stylet is very robust and the cone and shaft are broad. The labial disc and lips are dumb bell shaped and it has large lateral lips that are separated from the medial lips and the head region. [11] In a study in Argentina, perineal patterns of 100 females from a population of M. arenaria, race 2 growing on tomato plants were analyzed and moderate morphological variations observed. The overall shape was rounded in most cases, but it was oval-shaped in a small proportion (4%). Forty-six percent of females showed low dorsal arch while 38% depicted a high dorsal arc, while the rest were intermediate. Lines in the post-anal region were smooth or wavy, continuous or broken, occasionally forming shoulders (18% of females). Wings were generally not observed. Phasmids were visible in 25% of the patterns and the mean distance between them was 24.33 ± 1.61 mm. Only seven out of one hundred females presented perineal patterns with lateral lines weakly demarcated by forked striae. Adult females were pyriform and lacking a terminal protuberance in the posterior area of the body. The female body lengths ranged between 465 mm and 1,129 mm. The excretory pore of the females was located closer to the base of the stylet than to the median bulb, at approximately 2-stylet lengths, in agreement with a typical M. arenaria specimen. The stylet was dorsally curved. [5]

Second stage juveniles of this nematode are short (400–600 micrometers) with very short stylets (10-15micrometers). The stylet is lightly sclerotized with indistinct Knobs. The cephalic framework is also weakly sclerotized. The esophageal gland overlaps the intestine ventrally and the tail tapers to a pointed tip with a clear terminus [10] In a study, second stage juveniles (J2s) averaged 458.51 ± 20.48 mm in length and 15.35 ± 0.76 mm in width. The rectum was undilated. Tail length (from anus to posterior end) was 56.21 ± 2.78 mm and the tail tip was rounded. [5]

Males of M. arenaria are long (1.0 to 2.0 mm). The stylet is short and has distinct knobs. The esophageal gland overlaps the intestine ventrally. The tail is short and rounded and has no bursa. Spicules open a short distance from the tail tip. [10] The males also have a head cap that is low and slopes posteriorly with 2 or 3 incomplete annulations around the head region. The stylet is pointed and the lumen opening has a small protuberance on the ventral side. [11] From their study, Garcı´a and Sa´nchez-Puerta, (2012) also reported that the mean length of the male body was 1.6 ± 0.31 mm. The head of the males was flat to concave and showed a moderately elevated labial disc. The males also had four lateral lines, which were easily observed. [5]

Symptoms of root knot disease of peanut

These nematodes cause symptoms both on leaves and roots. Foliar symptoms of root-knot disease may be expressed at any time during the growing season. These symptoms of nematode damage on peanut plants range from stunting, yellowing, wilting and even plant death. [9] Ferris (1999–2012), also reported that nematodes cause yellowing; mid-day wilting; symptoms of water and nutrient stress; and sometimes death, especially if the nematode is interacting with other organisms. [7] They can appear in a peanut crop beginning about 100 days after planting or after periods of dry hot weather. Areas of root-knot nematode damaged peanut are usually round to oblong in shape, and rows of infected plants may never overlap as those of healthy plants. It is common for plants to wilt and eventually die in areas where nematode populations are high. [9]

Root symptoms are similar to those caused by all nematodes including a reduction in number of feeder roots and root stunting, but root knot nematodes cause unique symptoms on roots and pods. Nematodes cause galls (knots) to form on both roots and pods of the peanut, and these galls are highly diagnostic for root-knot nematode presence compared to other nematodes affecting peanut. The presence of galls on roots, pegs and pods appears as single or multiple wart-like growths that may or may not be discolored. As root knot nematode infection progresses, and generally later in the season, secondary root and pod rots cause further damage and eventual death of the plants. [9]

Many soil-borne fungi, especially Sclerotium rolfsii (which causes southern stem rot) and Sclerotinia minor (which causes Sclerotinia blight), will infect the weakened peanut plants and cause more plant death. Root knot nematode infection of the peg weakens the peg so that it breaks during harvest, contributing to additional yield losses because the detached pods are then left in the soil. Infection of the pods leads to a decline in yield quality. [3]

The damage threshold, or the initial nematode population density at which peanut yields begin to decline, has been reported to be in the range of 1 to 10 eggs and second stage juveniles per 500 cm3 soil for M. arenaria on susceptible peanut cultivars.

Reproduction and life cycle

Reproduction occurs mitotically by parthenogenesis and the species has chromosome numbers that range from 30 to 50 [2] The life cycle of all Meloidoigyne spp is similar but they have different temperature requirements. At temperatures ranging from 32.8 to 39.50C, M. arenaria reached the egg laying stage in about 21 days on peanut and completed its life cycle in 32 days. The population levels increased faster from a starting level of 10 juveniles per plant that from 1000 or 10,000 per plant. [8]

Adult females deposit eggs into a protective gelatinous matrix, near or just outside the root surface. A single female lays about 500 to 1,500 eggs during her life, which lasts about two to three months. Eggs hatch only under favorable conditions, such as adequate moisture and warm temperatures. Root knot nematode development begins inside the egg. After the completion of embryogenesis, the first-stage juvenile remains inside the egg until it molts into the second stage juvenile. The first stage juvenile (J1) lacks a stylet. Second stage juveniles (J2) hatch from the egg and move freely in the soil in quest for a suitable host plant. Once they find suitable host and enter the root with the help of the stylet, they start to feed within 24 hours, inducing giant cells to form. J2s then molt thrice (to J3, J4 and then the adult) before they mature in to adults. Adult males remain vermiform and get out of the root while females swell and obtain the pyriform/round shape. Females lay eggs in the gelatinous matrix which hatch again and the cycle is repeated if environmental conditions are favorable. [12] The length of the life cycle depends on environmental factors mostly temperature and host status. It may take about 1 month to complete the life cycle. The nematodes also have a very high reproductive rate. [1]

Feeding behavior

Just like the other root knot nematodes, to be able to feed within the host, this nematode must establish an interaction with the plant. J2s are attracted to the root tip in the zone of elongation and the areas of lateral root emergence. Initially it was reported that they are attracted by CO2, and apparently by small molecules that are dialysable – perhaps amino acids. Recent studies suggest that the attraction may not be to CO2 but to lower pH resulting from carbonic acid formed from the CO2 in solution. [7]

The second juvenile (J2) penetrates zone of elongation by mechanical (stylet thrusts) and probably chemical (cellulase and pectinase) means. It moves between, rather than through, cortical cells towards root apex, turns at the meristem, and migrates back to the vascular cylinder in the zone of cell differentiation. [7] Once the J2 is in the root, they migrate intracellularly to the provascular cells and begin to parasitize cells within 24 hours. The nematode initiates formation of the giant cell (also called a nurse cell) from potential vascular tissue. Sub ventral gland become prominent after penetrating the root, and it could be playing a role of secreting enzymes that play a role in the formation of the giant cell which is a large cell with several nuclei. Giant cell are very large in size (100 fold increase), with reduced vacuoles and they are multinucleate containing about 40 to 100 nuclei. The female feeds from the giant cell as it expands further posteriorly accumulating eggs. After formation of the giant cells, gall development occurs though these two events are separate. Galls result from hypertrophy and hyperplasia of the cells around the giant cells. Growth regulators (IAA) are thought to have a role in cell enlargement since they increases cell wall plasticity. [7]

Host range

M. arenaria parasitizes peanut, vegetables, grasses, fruit ornamentals and tobacco. [1] The root-knot nematode, M. arenaria can infect almost every plant family. [5] While characterizing the host range of the peanut root knot nematode, López-Pérez et al., 2011, reported that the most frequent hosts of the peanut root knot nematode were vegetables, fruit trees, tobacco, grapevine, and weeds. [6]

Management

Promising ongoing research and other issues

Points to ponder

See also

Related Research Articles

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.

<i>Meloidogyne incognita</i> Nematode worm, plant disease, many hosts

Meloidogyne incognita, 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.

<span class="mw-page-title-main">Soybean cyst nematode</span> Species of roundworm

The soybean cyst nematode (SCN), Heterodera glycines, is the most devastating pest to soybean crop yields in the U.S., targeting the roots of soybean and other legume plants. When infection is severe SCNs cause stunting, yellowing, impaired canopy development, and yield loss. The symptoms caused by SCNs can go easily unrecognized by farmers—in some cases there are no warning symptoms before a loss of 40% of the yield. Due to the slight stunting and yellowing, many farmers may mistake these symptoms as environmental problems when in fact they are SCNs. Another symptom of SCNs that may affect farmers' yields is stunted roots with fewer nitrogen-fixing nodules. Due to the fact that soybean cyst nematodes can only move a few centimeters in the soil by themselves, they mostly are spread via tillage or plant transplants. This area of infection will look patchy and nonuniform making diagnosis more difficult for farmers. They can be seen in the roots of summer soybean plants if the roots are taken out very carefully and gently washed with water. The egg masses should be seen as bright white or yellow "pearls" on the roots. The later the roots are pulled the harder it will be to diagnose due to the SCNs female dying and turning a much darker color, forming a "cyst". The best way to know if a field is infected by soybean cyst nematodes is to take a soil sample to a nematologist.

<span class="mw-page-title-main">Potato cyst nematode</span> Genus of roundworms that live on potato roots

Potato root nematodes or potato cyst nematodes (PCN) are 1-mm long roundworms belonging to the genus Globodera, which comprises around 12 species. They live on the roots of plants of the family Solanaceae, such as potatoes and tomatoes. PCN cause growth retardation and, at very high population densities, damage to the roots and early senescence of plants. The nematode is not indigenous to Europe but originates from the Andes. Fields are free from PCN until an introduction occurs, after which the typical patches, or hotspots, occur on the farmland. These patches can become full field infestations when unchecked. Yield reductions can average up to 60% at high population densities.

<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.

Paratrichodorus minor is a species of nematode in the family Trichodoridae, the stubby-root nematodes. It occurs in tropical and subtropical regions of the world. It damages plants by feeding on the roots and it is a vector of plant viruses. It is a pest of some agricultural crops.

<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>Pratylenchus penetrans</i> Species of roundworm

Pratylenchus penetrans is a species of nematode in the genus Pratylenchus, the lesion nematodes. It occurs in temperate regions worldwide, regions between the subtropics and the polar circles. It is an animal that inhabits the roots of a wide variety of plants and results in necrotic lesions on the roots. Symptoms of P. penetrans make it hard to distinguish from other plant pathogens; only an assay of soil can conclusively diagnose a nematode problem in the field. P. penetrans is physically very similar to other nematode species, but is characterized by its highly distinctive mouthpiece. P. penetrans uses its highly modified mouth organs to rupture the outer surface of subterranean plant root structures. It will then enter into the root interior and feed on the plant tissue inside. P. penetrans is considered to be a crop parasite and farmers will often treat their soil with various pesticides in an attempt to eliminate the damage caused by an infestation. In doing this, farmers will also eliminate many of the beneficial soil fauna, which will lead to an overall degradation of soil quality in the future. Alternative, more environmentally sustainable methods to control P. penetrans populations may be possible in certain regions.

Heterodera carotae is a plant pathogenic nematode commonly known as the carrot root nematode or carrot cyst nematode. It is found in Europe, Cyprus and India and is considered an invasive species in the United States. It causes damage to carrot crops and is very specific in its choice of hosts, only infecting Daucus carota and Daucus pulcherrima.

<i>Heterodera schachtii</i> Species of roundworm

Heterodera schachtii, the beet cyst eelworm or sugarbeet nematode, is a plant pathogenic nematode. It infects more than 200 different plants including economically important crops such as sugar beets, cabbage, broccoli, and radish. H. schachtii is found worldwide. Affected plants are marked by stunted growth, wilting, yellowing, decreased yields, and death. While there are many methods of control, crop rotation with non-susceptible plants is preferred.

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.

<i>Paratylenchus hamatus</i> Species of roundworm

Paratylenchus hamatus, the fig pin nematode, is a species of migratory plant endoparasites, that causes lesions on plant roots resulting in symptoms of chlorosis, wilting and ultimately yield losses. They move and feed on different parts of host tissue throughout their life cycle in order to find enough susceptible host tissue to survive and reproduce. A wide range of host plant species are susceptible to the fig pin nematode, including many valuable fruit and vegetable crops such as figs, carrots and celery. They are also commonly found associated with woody perennials in California. P. hamatus inhabits soils in both Europe and North America, and was originally isolated from fig in central California in 1950.

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.

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.

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.

Globodera tabacum, commonly known as a tobacco cyst nematode, is a plant parasitic nematode that mainly infests the tobacco plant, but also plants in family Solanaceae.

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.

Heterodera zeae, the corn cyst nematode (CCN), is a plant parasitic nematode that feeds on Zea mays (maize/corn). The CCN has a limited economic impact worldwide due to its high soil temperature requirements.

References

  1. 1 2 3 Howard Ferris. "Meloidogyne arenaria". Archived from the original on 2007-06-30..
  2. 1 2 3 4 5 Chitwood; Neal (1949). "Meloidogyne arenaria".
  3. 1 2 3 4 5 6 J. L. Starr; E. R. Morgan. "Management of the Peanut Root-knot Nematode, Meloidogyne arenaria, with Host Resistance". Department of Plant Pathology, Texas Agricultural Experiment Station, Texas A&M University.
  4. ↑ 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.
  5. 1 2 3 4 5 6 Laura Evangelina Garci´a,1 Mari´a Virginia Sa´ nchez-Puerta, 2012. Characterization of a Root-Knot Nematode Population of Meloidogyne arenaria from Tupungato (Mendoza, Argentina)
  6. 1 2 J. A. López-Pérez , M. Escuer , M. A. Díez-Rojo, L. Robertson, A. Piedra Buena, J. López-Cepero, and A. Bello, 2011. Host range of Meloidogyne arenaria (Neal, 1889) Chitwood, 1949 (Nematoda: Meloidogynidae) in Spain.
  7. 1 2 3 4 5 6 7 Howard Ferris (2012). "Meloidogyne". Archived from the original on 2017-09-09.
  8. 1 2 K. Evans, D.L. Trudgill, J. M. Webster, 1993. Plant parasitic Nematodes in Temperate Agriculture pp 228–231.
  9. 1 2 3 4 5 6 7 8 Jim Rich and Barry Tillman, 2009. Root-Knot Nematode Resistance in Peanut.
  10. 1 2 3 4 Eisenback, J. D 1998. Plant and nematode interactions 1998 pp. 37–63. Morphology and systematics. Department of Plant Pathology, Physiology and Weed Science, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA Edited by Barker, K. R.; Pederson, G.A.; and Windham, G. L. Agronomy series No. 36. ISBN   0-89118-136-9. Record Number 20013030208.
  11. 1 2 Eisenback, J.D.; Hirschmann, H.; Sasser, J.N.; A.C.Triantaphyllou (1981). "A Guide to the Four Most Common Species of Root-Knot Nematodes, (Meloidogyne species) with a pictorial key" (PDF). Depts. Plant Pathol. and Genetics and U.S. Agency for International Development, Raleigh, NC.
  12. ↑ Siddharth Tiwari and, Jon D. Eisenback, Roger R. Youngman, 2009. Root-knot Nematode in Field Corn Department of Entomology, Virginia Tech 2Department of Plant Pathology, Physiology, and Weed Science, Virginia Tech 3Extension Entomologist, Virginia Tech
  13. ↑ "Chemical Methods of Nematode Management". Archived from the original on 2017-10-05.
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.