Meloidogyne chitwoodi
(columbia root-knot nematode)

Pictures

Top of page

Identity

Top of page

Preferred Scientific Name

• Meloidogyne chitwoodi Golden, O'Bannon, Santo & Finley, 1980

Preferred Common Name

• columbia root-knot nematode

International Common Names

• French: nématode cécidogène de columbia

EPPO code

• MELGCH (Meloidogyne chitwoodi)

Taxonomic Tree

Top of page

• Domain: Eukaryota
•     Kingdom: Metazoa
•         Phylum: Nematoda
•             Family: Meloidogynidae
•                 Genus: Meloidogyne
•                     Species: Meloidogyne chitwoodi

Notes on Taxonomy and Nomenclature

Top of page References to Meloidogyne chitwoodi B-type in van Meggelen et al. (1994) refer to M. fallax (Karssen, 1996).

Description

Top of page Adult males and the second-stage juveniles are vermiform, motile animals, similar in general appearance to free-living soil nematodes. Females are characteristically pear-shaped, pearly-white and sedentary. The male is 887-1268 µm in length and 22-37 µm in width with a slight taper at each end. The tail is short, 4.7-9.0 µm and rounded. Cuticular annules are distinct and are more prominent near each end. The female is 430-740 µm in length and 344-518 µm in width. Second-stage juveniles are 336-417 µm in length and 12.5-15.5 µm in width, tail short, 39-47 µm, scarcely tapered and hyaline. Eggs are 79-92 µm in length and 40-46 µm in width.

Distribution

Top of page

M. chitwoodi was first described from the Pacific Northwest of the USA in 1980, its common name deriving from the Columbia River between Oregon and Washington states. It is not clear whether this is its area of origin. It was first detected in the EPPO region in the 1980s, in the Netherlands, but a review of old illustrations and old specimens of Meloidogyne suggests that it may have occurred earlier (in the 1930s) and may have been present throughout the intervening period (OEPP/EPPO, 1991). It is possible that M. chitwoodi has a wider distribution, undetected, in Europe than is currently known; the question is now actively under investigation.

A record for Wyoming, USA, was incorrectly included in CABI/EPPO (2000). The record for Virginia, USA, has been changed to 'Absent, confirmed by survey' following surveys conducted by Virginia Department of Agriculture and Consumer Services (2007-2010) and the Department of Plant Pathology, Physiology and Weed Science, Virginia Tech.

Distribution Table

Top of page

The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.

Risk of Introduction

Top of page M. chitwoodi has been added to the EC Plant Health Directive 77/93/EEC.

A comparison of the air temperatures found in Finland with those found across the present distribution of the pest indicated that the nematode could survive and produce two generations per year in the southern part of Finland. Baker and Dickens (1993) concluded from their PRA that M. chitwoodi would be likely to produce three generations in the UK. They did not feel capable of predicting the likely economic impact of the pest, as this could depend on a number of other unknown factors such as soil wetness, varietal susceptibility and quality control thresholds. A recent PRA for Germany (Braasch et al., 1996) led to the conclusion that M. chitwoodi was most likely to be damaging on potatoes in the north-west of the country, in the area adjoining the Netherlands. Countries further south in the EPPO region would provide climatic conditions suitable for as many as four generations per year.

Potato crops would be most at risk from M. chitwoodi in the EPPO region. For a number of reasons, it represents a greater threat than other Meloidogyne species already widespread in the EPPO region, in particular M. hapla with which it often forms mixed populations. M. chitwoodi is less easily controlled by nematicides, it has a wider host range, it produces more severe tuber symptoms and is tolerant of lower soil temperatures. In fact, the soil temperature requirements for population development of M. chitwoodi are similar to those of Globodera rostochiensis (Tiilikkala et al., 1995), suggesting that the former species could occupy the same geographical distribution as the latter.

Hosts/Species Affected

Top of page M. chitwoodi has a wide host range among several plant families (Santo et al., 1980; O'Bannon et al., 1982), including crop plants and common weed species. Potatoes and tomatoes are good hosts, while barley, maize, oats, sugarbeet, wheat (Triticum aestivum) and various Poaceae (grasses and weeds) will maintain the nematode.

Moderate to poor hosts occur in the Brassicaceae, Cucurbitaceae, Fabaceae, Lamiaceae, Liliaceae, Umbelliferae and Vitaceae.

Fourie et al. (1998), working with a South African population of M. chitwoodi, reported Lycopersicon esculentum, Brassica rapa, Eragrostis tef and Lolium multiflorum as supporting high populations, whereas Eragrostis curvula, Arachis hypogaea and Zea mays were poor hosts.

Korthals et al. (2000) assessed host plant suitability at two sites in the Netherlands. Population growth of M. chitwoodi was greatest in potato, rye and summer wheat while nematodes in sugarbeet, hemp, perennial ryegrass and Tagetes patula remained equivalent to those of fallow. Because of poor reproduction, they recommended perennial ryegrass as a cover crop after cereals, maize, carrots or potatoes.

Lucerne is a good host for race 2 but not for race 1 (see Biology and Ecology for information on races), whereas carrots are a non-host for race 2 but a good host for race 1. Ferris et al. (1994a,b), investigating suitable crops for rotation with potato in the presence of race 1 in the USA, recommend Amaranthus, lucerne, rape (Brassica napus var. oleifera), Raphanus sativus var. oleifera and safflower (Carthamus tinctorius). In the Netherlands, host crops recorded to be attacked by M. chitwoodi are carrots, cereals, maize, peas, Phaseolus vulgaris, potatoes, Scorzonera hispanica, sugarbeet and tomatoes (OEPP/EPPO, 1991).

Recent studies have expanded information on the host range of M. chitwoodi (e.g. Brinkman et al., 1996; Griffin and Rumbaugh, 1996). Nijs et al. (2004) presented the results of experiments performed in the Netherlands and provided information on the host status of many plants together with an assessment of their potential phytosanitary risk.

Host Plants and Other Plants Affected

Top of page

Growth Stages

Top of page Pre-emergence, Seedling stage, Vegetative growing stage

Symptoms

Top of page Symptoms of M. chitwoodi vary according to host, population density of the nematode and environmental conditions. Above-ground symptoms are often not obvious but may consist of varying degrees of stunting, lack of vigour and a tendency to wilt under moisture stress, all leading to reduced yield. The galls produced on potato tubers by M. chitwoodi differ from those caused by other species of Meloidogyne. M. hapla, for example, forms small but distinct galls (together with extensive root proliferation) while M. incognita forms large, easily noticeable galls. The symptoms caused by M. chitwoodi are often not easily detected and are more apparent in some cultivars than in others; tubers may, in some cases, be heavily infected without visible symptoms. When present, the galls appear as small raised swellings on the tuber surface above the developing nematodes. A number of galls may be concentrated on one area of the tuber or single galls may be scattered near eyes or lesions. Internal tissue below the gall is necrotic and brownish. Adult females are visible just below the surface as glistening, white, pear-shaped bodies surrounded by a brownish layer of host tissue. Potato roots may also be infected, but this is difficult to detect without a magnifying lens, as little or no galling occurs, even in heavy infestations. The spherical bodies of females may protrude from the surface of small rootlets surrounded posteriorly by a large egg-filled sac which becomes dark-brown with age.

In other crops, root galls and reduced root production decrease yields and marketability. Gall formation occurs on most cereals but is more noticeable on wheat and oats than on barley or maize. In tomatoes, M. chitwoodi produces root galls in some cultivars but not in others.

List of Symptoms/Signs

Top of page

Biology and Ecology

Top of page The life cycle of M. chitwoodi takes approximately 3-4 weeks under favourable conditions. Juveniles hatch from eggs in soil or on the root surface. Second-stage juveniles (the infective stage) penetrate root tips through unsuberized epidermal cells or wounds and move into the cortical region. Soon after entry, nematodes stimulate giant cell and gall formation in the host tissue. Necrotic lesions occur in the cortex. Juveniles then swell to become sausage-shaped, stop feeding and undergo three rapid successive moults to become adult males or females. Adult males have slender, vermiform bodies; they leave the root and are found free in the rhizosphere or near the protruding body of the female. However, as in the case of other Meloidogyne spp., it is probable that males are largely functionless and reproduction is nearly always parthenogenetic. Adult females have characteristically pear-shaped, pearly-white bodies and they are found embedded in host tissue. Eggs are laid by the female in a gelatinous sac near the root surface. In potato tubers, modified host cells form a protective layer or 'basket' around the egg mass and the juveniles as they hatch. The egg shell itself is hyaline with no visible markings.

M. chitwoodi passes the winter as eggs or juveniles and can survive extended periods of sub-zero temperatures. M. chitwoodi needs a temperature of 4°C for hatching and penetrating roots, and 6°C for development. Charchar and Santo (2001) reported on the effect of temperature on embryonic development and hatching of M. chitwoodi in Brazil. M. chitwoodi requires 600-800 degree-days to complete the first generation, whilst subsequent generations require 500-600 degree-days. Studies on potato in Oregon, USA, during 1992-1994 indicated that rapid population increase occurred after 1200 degree-days (Ingham and Rykbost, 1995). M. hapla requires a similar number of degree-days for development but does not begin development until temperatures rise above 10°C. Population dynamics in relation to degree-day accumulation have been considered by Pinkerton et al. (1991). M. chitwoodi was found to be more pathogenic at 25°C than at 30°C in glasshouse tests performed on yellow sweet clover (Griffin and Jensen, 1997). Brommer and Molendijk (2001) reported that there were at least two generations per year in fields naturally infected with M. chitwoodi in the Netherlands.

Several races of M. chitwoodi have been described, distinguished by slight differences in host range. The first two, known as race 1 and race 2, were in particular distinguished with regard to carrot and lucerne (Santo and Pinkerton, 1985; Mojtahedi et al., 1988). Race 3 has recently been described in California, USA (Mojtahedi et al., 1994). The nematode found in the Netherlands previously named M. chitwoodi B-type has been redescribed as a new species (M. fallax) (Karssen, 1996). Current research is attempting to clarify the position regarding races, Beek et al. (1999) proposing a pathotype scheme to describe intraspecific variation in pathogenicity.

Natural enemies

Top of page

Notes on Natural Enemies

Top of page Predatory mites (Hypoaspis aculeifer) were observed feeding on egg-masses of this nematode on tomato roots in Utah, USA (Inserra and Davis, 1983).

M. chitwoodi was relatively susceptible to the nematode-trapping fungi Monacrosporium ellipsosporum and M. cionopagum, compared with Heterodera schachtii, in laboratory tests (Jaffee and Muldoon, 1995). Jacobsen (2002) reviewed biological control of potato pathogens. Wishart et al. (2004) reported attachment of the spores of Pasteuria penetrans and P. nishizawae to juveniles of M. chitwoodi, M. fallax and M. hapla.

Pathway Vectors

Top of page

Plant Trade

Top of page

Plant parts not known to carry the pest in trade/transport
Bark
Bulbs/Tubers/Corms/Rhizomes
Flowers/Inflorescences/Cones/Calyx
Fruits (inc. pods)
Leaves
Stems (above ground)/Shoots/Trunks/Branches
True seeds (inc. grain)
Wood

Impact

Top of page M. chitwoodi reduces the market value of potatoes as a result of internal necrosis and external galling. Necrotic spots in the flesh of tubers of as little as 5% of a crop make it commercially unacceptable. Overall yields of tubers are also reduced. This species is considered to be the major nematode pest of potatoes in the Pacific Northwest states of the USA and the annual predicted loss there would be ca $40 million if control measures were not applied (Santo, 1994). No information is available on the economic impact of this pest in European countries.

Effects on other crops are not as marked nor as well documented, but yields of cereals (wheat, barley, oats and maize) have been shown to be significantly reduced by infestation (Santo and O'Bannon, 1981).

In the Netherlands, M. chitwoodi has recently been found to have damaged potato crops (and certain vegetables) in a limited area in the east of the country. This damage is apparently associated with sandy soils and a succession of warm summers. It is possible that M. chitwoodi has been present in the area for many years, undetected because it caused no significant damage (see Geographical Distribution).

M. chitwoodi has also caused damage to potatoes in Germany (Muller et al., 1996). The multiplication rate and damage probability of M. chitwoodi seems to depend mainly on weather conditions in spring and temperature accumulation during the vegetative period (Braasch et al., 1996).

Chaves and Torres (2000) reported the presence of M. chitwoodi on golf courses in Buenos Aires province, Argentina. Chaves and Torres (2001) reported the presence of M. chitwoodi in potato seed producing areas in Argentina. The nematode occurred in 12.5% of the samples taken.

Diagnosis

Top of page M. chitwoodi has been distinguished from M. fallax by esterase and malate dehydrogenase patterns (Karssen, 1996) and DNA methods (Petersen and Vrain, 1996; Williamson et al., 1997; Zijlstra et al., 1997). A number of molecular based methodologies have been developed to characterize the species and to help differentiate it from related root-knot nematodes (Castagnone-Sereno et al., 1998, 1999; Castagnone-Sereno, 2000; Zijlstra, 2000; Fourie et al., 2001; Wishart et al., 2002; Fargette et al., 2005; Skantar and Carta, 2005).

Detection and Inspection

Top of page

The presence of M. chitwoodi in infested soil can be determined by sampling and extraction of the second-stage juveniles, using a standard nematode extraction procedure for free-living nematodes of this size. External symptoms on tubers are obvious in the case of heavy infestations but, where nematode numbers are low or in the early stages of infection, such symptoms are not obvious. Clearing and staining of the tissues can show the presence of nematodes (Hooper, 1986) but this can be a laborious procedure. Storage of lightly infested tubers may lead to the development of obvious external symptoms.

Means of Movement and Dispersal

M. chitwoodi has very limited potential for natural movement; only second-stage juveniles can move in the soil and, at most, only a few tens of centimetres. The most likely method of introducing M. chitwoodi into a new area is through the movement of infected or contaminated planting material. Infected host plants or host products such as bulbs or tubers can easily transport the nematode. The movement of non-host seedling transplants, nursery stock, machinery or other products which are contaminated with soil infested with M. chitwoodi could also result in spread. Infective larvae of this genus have been known to persist for more than one year in the absence of host plants. Nematode movement can also be facilitated by contaminated irrigation water.

Detection based on host plant symptoms, and identification by morphological and molecular methods are detailed in OEPP/EPPO (2009).

Similarities to Other Species/Conditions

Top of page M. chitwoodi closely resembles M. hapla; it can be distinguished from this and other species by the perineal pattern, the appearance of vesicles or vesicle-like structures in the median bulb of the adult female and by the short, blunt, larval tail which has a hyaline, rounded (not tapered) terminus (Golden et al., 1980; Nyczepir et al., 1982; Jepson, 1985).

M. chitwoodi differs from M. fallax by having smaller female and male stylet length, presence of small, irregular outlined male and female stylet knobs, male labial disk not elevated, shorter juvenile body-, tail-, and hyaline tail length, different hyaline tail shape, hemizonid position, esterase and malate dehydrogenase patterns (Karssen, 1996).

Schemes have been described to differentiate M. chitwoodi from M. hapla, M. microtyla and M. incognita by differential host tests (Townshend et al., 1984), and also to distinguish the two races of M. chitwoodi (Mojtahedi et al., 1988). Biochemical methods have also been used. A diagnostic DNA probe which distinguishes M. chitwoodi from M. hapla has been developed by Piotte et al. (1995) and Wishart et al. (2002) used a PCR-based technique involving the ribosomal intergenic spacer. Recently, M. chitwoodi has been distinguished from M. fallax by DNA methods (Petersen and Vrain, 1996; Williamson et al., 1997; Zijlstra et al., 1997; Castagnone-Sereno et al., 1999; Castagnone-Sereno, 2000; Zijlstra, 2000; Wishart et al., 2002).

Prevention and Control

Top of page

Chemical Control

Control measures currently used against other root-knot nematodes have proved to be less effective against M. chitwoodi. In north-western USA, crop failures in several potato fields have been attributed to M. chitwoodi despite the use of spring soil fumigations.
Cultural Control and Sanitary Methods

Recent work on sugarbeet suggests that late drilling and reduced irrigation can play a part in reducing damage to crops (Heijbroek, 1996).

Crop rotation with cereals is often used to reduce populations of M. hapla. However, M. chitwoodi reproduces well on wheat, oats, barley and maize. Therefore, rotation with any of these crops will favour a build-up rather than a decrease of M. chitwoodi populations in infested soils. There are, however, other crops which will reduce populations (see Host Range) which can be used in rotations. Brinkman et al. (1996) suggested that chicory cultivars (Cichorium intybus), Dahlia (cv. Vuurvogel) and borage (Borago officinalis) supported low populations of M. chitwoodi and can offer alternatives in crop rotations. However, further studies are necessary to collect more information on crops which can be used in rotation to reduce nematode populations.

Some success has been achieved by the incorporation of green manure into the soil, which reduces population densities of M. chitwoodi (Mojtahedi et al., 1993a, b; Suloiman and Hafez, 1996).

Measures similar to those for potato cyst nematodes (EPPO/CABI, 1992) would appear relevant, i.e. that consignments of rooted plants should come from areas where the pest does not occur or from fields found free from the pest. Suitable survey and test methods have still to be established. Freedom from M. chitwoodi should be specifically assured by certification schemes for seed potatoes.

Host-Plant Resistance

Potato cultivars differ in their tolerance of M. chitwoodi (van Riel, 1993). There is interest in breeding for host resistance to M. chitwoodi, for example, in potatoes, using resistance from Solanum bulbocastanum and other sources (Brown et al., 1991; Austin et al., 1993; Janssen et al., 1997) and cereals (Jensen and Griffin, 1994). Yu (2001) and Yu and Lewellen (2004) registered nematode-resistant sugarbeet germplasm; Zoon et al. (2002) discussed durable resistance against M. chitwoodi and M. fallax whilst Brown et al. (1999, 2003, 2004) investigated resistance to M. chitwoodi in potato and evaluated several wild Solanum species as sources of resistance. Tovar-Soto et al. (1997) reported on the response of five potato genotypes to M. chitwoodi race 2 in Mexico. Berthou et al. (2003) characterized virulence in populations of M. chitwoodi by challenging with Capsicum annuum line PM217. Their results demonstrated great polymorphism in M. chitwoodi populations and the existence of a major gene in pepper controlling a specific resistance against some nematode populations.

IPM Programmes

Guidelines for integrated pest management in potatoes are still being devised in those countries affected by this M. chitwoodi (Ferris et al., 1994a,b; Santo, 1994; Hafez et al., 1997).

References

Top of page

Anon, 2005. Meloidogyne chitwoodi and Meloidogyne fallax. Bulletin OEPP, 34(2): 315-320

Austin S, Pohlman JD, Brown CR, Mojtahedi H, Santo GS, Douches DS, Helgeson JP, 1993. Interspecific somatic hybridization between Solanum tuberosum L. and S. bulbocastanum Dun. as a means of transferring nematode resistance. American Potato Journal, 70(6):485-495; 36 ref

Baker RHA, Dickens JSW, 1993. Practical problems in pest risk assessment. In: Ebbels DL, ed. Plant Health and the European Single Market. Farnham, UK: BCPC. pp 209-220

Beek JGvan der, Maas PWT, Janssen GJW, Zijlstra C, Silfhout CHvan, 1999. A pathotype system to describe intraspecific variation in pathogenicity of Meloidogyne chitwoodi. Journal of Nematology, 31(4):386-392; 30 ref

Berthou F, Palloix A, Mugniery D, 2003. Characterisation of virulence in populations of Meloidogyne chitwoodi and evidence for a resistance gene in pepper Capsicum annuum L. line PM 217. Nematology, 5(3): 383-390

Braasch H, Wittchen U, Unger JG, 1996. Establishment potential and damage probability of Meloidogyne chitwoodi in Germany. Bulletin OEPP, 26(3/4):495-509; 21 ref

Brinkman H, Goossens JJM, Riel HRvan, 1996. Comparative host suitability of selected crop plants to Meloidogyne chitwoodi Golden et al. 1980 and M. fallax Karssen 1996. Anzeiger fu^umlaut~r Scha^umlaut~dlingskunde, Pflanzenschutz, Umweltschutz, 69(6):127-129; 13 ref

Brinkman H, van Riel HR, 1990. In: Jaarboek 1989-1990. Wageningen, Netherlands: Directie Gewasbescherming, Plantenziektenkundige Dienst

Brommer E, Molendijk LPG, 2001. Population development of the root-knot nematodes Meloidogyne chitwoodi and M. fallax in potato. Gewasbescherming, 32(6):148-150; 2 ref

Brown CR, Mojtahedi H, Bamberg J, 2004. Evaluation of Solanum fendleri as a source of resistance to Meloidogyne chitwoodi. American Journal of Potato Research, 81(6): 415-419

Brown CR, Mojtahedi H, Santo GS, 1991. Resistance to Columbia root-knot nematode in Solanum ssp. and in hybrids of S. hougasii with tetraploid cultivated potato. American Potato Journal, 68(7):445-452; 17 ref

Brown CR, Mojtahedi H, Santo GS, 1999. Genetic analysis of resistance to Meloidogyne chitwoodi introgressed from Solanum hougasii into cultivated potato. Journal of Nematology, 31(3):264-271; 25 ref

Brown CR, Mojtahedi H, Santo GS, 2003. Characteristics of resistance to Columbia root-knot nematode introgressed from several Mexican and North American wild potato species. Acta Horticulturae, 619: 117-125

CABI/EPPO, 1998. Distribution maps of quarantine pests for Europe (edited by Smith IM, Charles LMF). Wallingford, UK: CAB International, xviii + 768 pp

CABI/EPPO, 2000. Meloidogyne chitwoodi. Distribution Maps of Plant Diseases, Map No. 803. Wallingford, UK: CAB International

CABI/EPPO, 2012. Meloidogyne chitwoodi. [Distribution map]. Distribution Maps of Plant Diseases, No.April. Wallingford, UK: CABI, Map 803 (Edition 2)

Castagnone-Sereno P, 2000. Use of satellite DNA for specific diagnosis of the quarantine root-knot nematodes Meloidogyne chitwoodi and M. fallax. Bulletin OEPP, 30(3/4):581-584; 11 ref

Castagnone-Sereno P, Leroy F, Bongiovanni M, Zijlstra C, Abad P, 1999. Specific diagnosis of two root-knot nematodes, Meloidogyne chitwoodi and M. fallax, with satellite DNA probes. Phytopathology, 89(5):380-384; 21 ref

Castagnone-Sereno P, Semblat JP, Leroy F, Abad P, 1998. A new AluI satellite DNA in the root-knot nematode Meloidogyne fallax: relationships with satellites from the sympatric species M. hapla and M. chitwoodi. Molecular Biology and Evolution, 15(9):1115-1122; 37 ref

Charchar JM, Santo GS, 2001. Effect of temperature on the embryogenic development and hatching of Meloidogyne chitwoodi races 1 and 2 and M. hapla. Nematologia Brasileira, 25(1):71-77; 13 ref

Charchar JM, Santo GS, 2008. Generation time and tuber infection by Meloidogyne chitwoodi race 1 and M. hapla on 'Russet Burbank' potato in field microplots. Nematologia Brasileira, 32(4):333-337

Chaves E, Torres MS, 2000. Nematode fauna associated with golf courses in the south-eastern region of the Buenos Aires province. Revista de la Facultad de Agronomi^acute~a (Universidad de Buenos Aires), 20(3):379-386; 31 ref

Chaves E, Torres MS, 2001. Potato parasitic nematodes in the seed potato producing areas of Argentina. Revista de la Facultad de Agronomi^acute~a (Universidad de Buenos Aires), 21(3):245-259; 37 ref

Eisenback JD, Stromberg EL, McCoy MS, 1986. First report of the Columbia root knot nematode (Meloidogyne chitwoodi) in Virginia. Plant Disease, 70:801

EPPO Reporting Service, 1991. Meloidogyne chitwoodi present. FAO Plant Protection Bulletin, 39(4):187

EPPO, 1997. Selected items from the EPPO Reporting Service of January 1997. EPPO Reporting Service, 97/001-97/003

EPPO, 2009. Meloidogyne chitwoodi and Meloidogyne fallax. Bulletin OEPP/EPPO Bulletin, 39(1):5-17. http://www.blackwell-synergy.com/loi/epp

EPPO, 2011. EPPO Reporting Service. EPPO Reporting Service. Paris, France: EPPO. http://archives.eppo.org/EPPOReporting/Reporting_Archives.htm

EPPO, 2014. PQR database. Paris, France: European and Mediterranean Plant Protection Organization. http://www.eppo.int/DATABASES/pqr/pqr.htm

EPPO, 2018. EPPO Global Database (available online). https://gd.eppo.int

Fargette M, Lollier V, Phillips M, Blok V, Frutos R, 2005. AFLP analysis of the genetic diversity of Meloidogyne chitwoodi and M. fallax, major agricultural pests. Comptes Rendus Biologies, 328(5):455-462. http://www.sciencedirect.com/science/journal/16310691

Ferris H, Carlson HL, Viglierchio DR, Westerdahl BB, Wu FW, Anderson CE, Juurma A, Kirby DW, 1994. Host status of selected crops to Meloidogyne chitwoodi. Journal of Nematology, 25(4 Supp):849-857; 25 ref

Ferris H, Carlson HL, Westerdahl BB, 1994. Nematode population changes under crop rotation sequences: consequences for potato production. Agronomy Journal, 86(2):340-348; 27 ref

Fourie H, Zijlstra C, McDonald AH, 1998. ITS-PCR sequence-based identification of Meloidogyne chitwoodi from Mooi River, South Africa, and screening of crops for host suitability. African Plant Protection, 4(2):107-111; 27 ref

Fourie H, Zijlstra C, McDonald AH, 2001. Identification of root-knot nematode species occurring in South Africa using the SCAR-PCR technique. Nematology, 3(7):675-680; 11 ref

Golden AM, O'Bannon JH, Santo GS, Finley AM, 1980. Description and SEM observations of Meloidogyne chitwoodi n.sp. (Meloidogynidae), a root-knot nematode on potato in the Pacific Northwest. Journal of Nematology, 12(4):319-327

Griffin GD, Jensen KB, 1997. Importance of temperature in the pathology of Meloidogyne hapla and M. chitwoodi on legumes. Journal of Nematology, 29(1):112-116; 14 ref

Griffin GD, Rumbaugh MD, 1996. Host suitability of twelve Leguminosae species to populations of Meloidogyne hapla and M. chitwoodi. Journal of Nematology, 28(3):400-405; 24 ref

Hafez SL, Al-Rehiayani S, Weiser GC, 1997. New concepts in management systems for potato nematodes in Idaho. Proceedings of the First International Workshop of Afro-Asian Nematologists Menoufiya University, Egypt, 8-13 June, 1997., 33-38

Hafez SL, Sundararaj P, 2002. Efficacy of chemical nematicides for the management of Meloidogyne chitwoodi on potato. International Journal of Nematology, 12(1):76-78; 11 ref

Hafez SL, Sundararaj P, 2002. Evaluation of autumn or spring applications of ethoprop for the management of Meloidogyne chitwoodi on potato. Nematologia Mediterranea, 30(2):181-183; 10 ref

Heijbroek W, 1996. The influence of soil type, tillage and cultural measures on the effect of root knot and cyst nematodes on sugar-beet root growth. In: Proceedings of the 59th IIRB Congress, Brussels, Belgium: 239-252

Heinicke, 1993. Catch crops and nematode control. Kartoffelbau, 44(7):300

Hooper DJ, 1986. Preserving and staining nematodes in plant tissues. In: Southey JF, ed. Laboratory methods for work with plant and soil nematodes. London, UK: HMSO

Ingham RE, Rykbost KA, 1995. Relationship between seasonal population growth of Columbia Root-Knot Nematode and soil degree days in potato. American Potato Journal, 72 (10):631

Inserra RN, Davis DW, 1983. Hypoaspis nr. aculeifer: a mite predacious on root-knot and cyst nematodes. Journal of Nematology, 15(2):324-325

IPPC, 2013. Meloidogyne chitwoodii never found in Denmark. IPPC Official Pest Report, No. DNK-14/1. Rome, Italy: FAO. https://www.ippc.int/

Jacobsen B, 2002. Biological control of potato pathogens. Biological control of crop diseases, 179-189; 56 ref

Jaffee BA, Muldoon AE, 1995. Susceptibility of root-knot and cyst nematodes to the nematode-trapping fungi Monacrosporium ellipsosporum and M. cionopagum. Soil Biology & Biochemistry, 27(8):1083-1090; 22 ref

Janssen GJW, Norel Avan, Janssen R, Hoogendoorn J, 1997. Dominant and additive resistance to the root-knot nematodes Meloidogyne chitwoodi and M. fallax in Central American Solanum species. Theoretical and Applied Genetics, 94(5):692-700; 31 ref

Jensen KB, Griffin GD, 1994. Resistance of diploid Triticeae species and accessions to the Columbia root-knot nematode, Meloidogyne. Journal of Nematology, 26(4 Supp.):635-639; 17 ref

Karssen G, 1996. Description of Meloidogyne fallax n. sp. (Nematoda : Heteroderidae), a root-knot nematode from The Netherlands. Fundamental and Applied Nematology, 19(6):593-599; 14 ref

Korthals GW, 2001. Maize root-knot nematode Meloidogyne chitwoodi: prevention and control. PPO-Bulletin Akkerbouw, No.1:30-33

Korthals GW, Brommer E, Molendijk LPG, 2000. Meloidogyne chitwoodi and Meloidogyne fallax a threat to potato production?. World potato congress: Proceedings of the Fourth World Potato Congress, Amsterdam, The Netherlands, 4-6 September, 2000, 207-208

Meggelen JCvan, Karssen G, Janssen GJW, Verkerk-Bakker B, Janssen R, 1994. A new race of Meloidogyne chitwoodi Golden, O'Bannon, Santo & Finley, 1980?. Fundamental and Applied Nematology, 17(1):93; 5 ref

Mnller J, Sturhan D, Rumpenhorst HJ, Braasch H, Unger JG, 1996. On the occurrence of a root-knot nematode (Meloidogyne chitwoodi) new to Germany. Nachrichtenblatt des Deutschen Pflanzenschutzdienstes, 48(6):126-131; 41 ref

Mojtahedi H, Santo GS, Brown CR, Ferris H, Williamson V, 1994. A new host race of Meloidogyne chitwoodi from California. Plant Disease, 78(10):1010; 1 ref

Mojtahedi H, Santo GS, Ingham RE, 1993. Suppression of Meloidogyne chitwoodi with sudangrass cultivars as green manure. Journal of Nematology, 25(2):303-311; 25 ref

Mojtahedi H, Santo GS, Wilson JH, 1988. Host tests to differentiate Meloidogyne chitwoodi races 1 and 2 and M. hapla. Journal of Nematology 20, 468-473

Mojtahedi H, Santo GS, Wilson JH, Hang AN, 1993. Managing Meloidogyne chitwoodi on potato with rapeseed as green manure. Plant Disease, 77(1):42-46; 21 ref

Nijs LJMF den, Brinkman H, Sommen ATC van der, 2004. A Dutch contribution to knowledge on phytosanitary risk and host status of various crops for Meloidogyne chitwoodi Golden et al., 1980 and M. fallax Karssen, 1996: an overview. Nematology, 6(3): 303-312

Nyczepir AP, O'Bannon JH, Santo GS, Finley AM, 1982. Incidence and distinguishing characteristics of Meloidogyne chitwoodi and M. hapla in potato from the northwestern United States. Journal of Nematology, 14(3):347-353

O'Bannon JH, Santo GS, Nyczepir AP, 1982. Host range of the Columbia root-knot nematode. Plant Disease, 66(11):1045-1048

Petersen DJ, Vrain TC, 1996. Rapid identification of Meloidogyne chitwoodi, M. hapla, and M. fallax using PCR primers to amplify their ribosomal intergenic spacer. Fundamental and Applied Nematology, 19(6):601-605; 23 ref

Pinkerton JN, Santo GS, Mojtahedi H, 1991. Population dynamics of Meloidogyne chitwoodi on Russet Burbank potatoes in relation to degree-day accumulation. Journal of Nematology, 23(3):283-290; 20 ref

Pinkerton JN, Santo GS, Ponti RP, Wilson JH, 1986. Control of Meloidogyne chitwoodi in commercially grown Russet Burbank potatoes. Plant Disease 70, 860-863

Piotte C, Castagnone-Sereno P, Bongiovanni M, Dalmasso A, Abad P, 1995. Analysis of a satellite DNA from Meloidogyne hapla and its use as a diagnostic probe. Phytopathology, 85(4):458-462; 25 ref

Riel HRvan, 1993. Comparison of potato cultivars in relation to their level of external symptoms on tubers caused by Meloidogyne chitwoodi. Mededelingen van de Faculteit Landbouwwetenschappen, Universiteit Gent, 58(2B):737-742; [^italic~Paper presented at the 45th International Symposium of Crop Protection, Gent, May 4, 1993.^roman~]; 9 ref

Santo GS, 1994. Biology and management of root-knot nematodes on potato in the Pacific Northwest. In: Zehner GW, Powelson ML, Jansson RK, Raman KV, eds. Advances in potato pest biology and management. St. Paul, USA: APS Press. pp. 193-201

Santo GS, O'Bannon JH, 1981. Pathogenicity of the Columbia root-knot nematode (Meloidogyne chitwoodi) on wheat, corn, oat and barley. Journal of Nematology, 13(4):548-550

Santo GS, O'Bannon JH, Finley AM, Golden AM, 1980. Occurrence and host range of a new root-knot nematode (Meloidogyne chitwoodi) in the Pacific northwest. Plant Disease, 64(10):951-952

Santo GS, Pinkerton JN, 1985. A second race of Meloidogyne chitwoodi discovered in Washington State. Plant Disease 69, 361

Skantar AM, Carta LK, 2005. Multiple displacement amplification (MDA) of total genomic DNA from Meloidogyne spp. and comparison to crude DNA extracts in PCR of ITS1, 28S D2-D3 rDNA and Hsp90. Nematology, 7(2): 285-293

Smith IM, McNamara DG, Scott PR, Holderness M, 1997. Quarantine pests for Europe. Second Edition. Data sheets on quarantine pests for the European Union and for the European and Mediterranean Plant Protection Organization. Quarantine pests for Europe. Second Edition. Data sheets on quarantine pests for the European Union and for the European and Mediterranean Plant Protection Organization., Ed. 2:vii + 1425 pp.; many ref

Suloiman AR, Hafez S, 1996. Suppression of Columbia root-knot nematode, Meloidogyne chitwoodi, race 2, with selected green manure crops. American Potato Journal 73(8): 387

Szalanski AL, Mullin PG, Harris TS, Powers TO, 2001. First report of Columbia root knot nematode (Meloidogyne chitwoodi) in potato in Texas. Plant Disease, 85(4):442; 2 ref

Thomas SH, Sanderson SA, Handoo ZA, 2001. First report of Columbia root-knot nematode (Meloidogyne chitwoodi) in potato in New Mexico. Plant Disease, 85(8):924; 1 ref

Tiilikkala K, Carter T, Heikinheimo M, VenSlSinen A, 1995. Pest risk analysis of Meloidogyne chitwoodi for Finland. Bulletin OEPP, 25(3):419-435; 54 ref

Tovar Soto A, Prado Vera ICdel, Zavaleta Mejfa EZ, Cadena Hinojosa M, Martfnez Garza A, 1997. Response of five genotypes of potato (Solanum tuberosum L.) to the Mexican populations of Meloidogyne incognita race 1 and M. chitwoodi race 2, under two temperature regimes. Revista Mexicana de Fitopatologi^acute~a, 15(1):22-25; 21 ref

Townshend JL, Potter JW, Davidson TR, 1984. Some monocotyledonous and dicotyledonous hosts of Meloidogyne microtyla. Plant Disease, 68(1):7-10

Walters SA, Barker KR, 1994. Current distribution of five major Meloidogyne species in the United States. Plant Disease, 78(8):772-774; 20 ref

Williamson VM, Caswell-Chen EP, Westerdahl BB, Wu FF, Caryl G, 1997. A PCR assay to identify and distinguish single juveniles of Meloidogyne hapla and M. chitwoodi. Journal of Nematology, 29(1):9-15; 19 ref

Wishart J, Blok VC, Phillips MS, Davies KG, 2004. Pasteuria penetrans and P. nishizawae attachment to Meloidogyne chitwoodi, M. fallax and M. hapla. Nematology, 6(4): 507-510

Wishart J, Phillips MS, Blok VC, 2002. Ribosomal intergenic spacer: a polymerase chain reaction diagnostic for Meloidogyne chitwoodi, M. fallax, and M. hapla. Phytopathology, 92(8):884-892; 45 ref

Wishart J, Phillips, MS, Paterson A, Blok VC, 2003. Comparison of gene expression in Solanum bulbocastanum infected with virulent and avirulent isolates of Meloidogyne chitwoodi. Plant Protection Science, 38(Special 2): 721-722

Yu MH, 2001. Registration of M6-1 root-knot nematode resistant sugarbeet germplasm. Crop Science, 41(1):278-279; 4 ref

Yu MH, Lewellen RT, 2004. Registration of root-knot nematode-resistant sugarbeet germplasm M6-2. Crop Science, 44(4): 1502-1503

Zijlstra C, 2000. Reliable identification of the quarantine root-knot nematodes Meloidogyne chitwoodi and M. fallax by PCR-based techniques. Bulletin OEPP, 30(3/4):575-579; 9 ref

Zijlstra C, Uenk BJ, Silfhout CHvan, 1997. A reliable, precise method to differentiate species of root-knot nematodes in mixtures on the basis of ITS-RFLPs. Fundamental and Applied Nematology, 20(1):59-63; 17 ref

Zoon FC, Golinowski W, Janssen R, Mugniery D, Phillips MS, Schlathoelter M, Smant G, Kruijssen lL van, Beek JG van der, 2002. Durable resistance against Meloidogyne chitwoodi and M. fallaz. Plant Protection Science, 38: 711-713

Distribution Maps

Top of page