Globodera pallida

 

Contents

 

Rev 12/27/2013

White cyst nematode, Potato cyst nematode Classification Hosts
Morphology and Anatomy Life Cycle
Return to Globodera Menu Economic Importance Damage
Distribution Management
Return to Heteroderidae Menu Feeding  References
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Classification:

      Tylenchida
       Tylenchina
        Tylenchoidea
         Heteroderidae
          Heteroderinae
                  
Globodera pallida
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Morphology and Anatomy:

Females: Cyst stage present. 

Body globose, spheroidal, with a short neck and no terminal cone.

Cuticle thick, with superficial, lace-like pattern; D-layer present. 

Vulva terminal, of medium length. Vulval area circumfenestrate; superficial tubercles near vulva. No anal fenestration, but anus and vulva lying both in a "vulval basin." Underbridge and bullae rarely present. 

All eggs retained in body (no egg-mass).

 

Note: Globodera rostochiensis passes through a yellow stage before rupturing root cortex. Globodera pallida remains creamy white until dying and becoming a brown cyst.
Males: Vermiform; body twisted into a C or S shape. 

Lateral field with four lines. 

Spicules greater than 30 m in length, distally pointed. 

No cloacal tubus. 

Tail short, hemispherical.

Second-stage juveniles: Stylet less than 30 m long.

Lateral field with four lines.

Esophageal glands filling body cavity. 

Tail conical, pointed, with terminal half hyaline.

Phasmids punctiform.

There are some morphological differences between G. pallida and G. rostochiensis; e.g., in juvenile lip region, etc.

 

Several pathotypes of G. rostochiensis exist: British A, Dutch A,B,C.

For G. pallida: British B and E, Dutch D.

Pathotype classifications are based on ability of nematode to reproduce on resistant cultivars.

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Distribution:

Wide distribution in potato-growing regions of Europe. Discovered in Idaho in the US in April, 2006; extent of infestation under investigation..  Molecular diagnosis suggests that the Idaho population is similar to that in parts of Europe which are, in turn, similar to populations in southern Peru near Lake Titicaca (Blok and Phillips, 2012).

Genus probably originated in Peru with Solanum tuberosum and other Solanum spp.

Based on information obtained from the International Potato Center, EPPO, Globodera pallida meeting in Boise Idaho (May, 2006), and literature review, the presence of Potato Cyst Nematode (PCN), Globodera pallida, has been reported in the following countries:

Europe: Austria, Belgium, Croatia, Czechia, Faroe Islands, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Spain, Sweden, Switzerland, United Kingdom.

As of 2006, it is reported as eradicated in Denmark.

Asia: Cyprus, India, Pakistan, Turkey.

Africa: Algeria, Tunisia.

North America: Canada (and now Idaho).

Central America: Panama.

South America: Argentina, Bolivia, Chile, Colombia, Ecuador, Falkland Islands, Peru, Venezuela.

Reports of occurrence in several other countriies are considered invalid or unreliable as of May, 2006.

Other than the discovery in Idaho, G. pallida is not reported from USA.

In 14 of the countries, the races of the nematode have been identified.

In 63% of the countries infested with PCN there are no data about races. 

The International Potato Center in Lima, Peru maintains a worldwide collection of races and offers a free service for species and race identification.

(Matos and Canto-Saenz, 1990; EPPO, 2006)

 

Reported Distribution 2011:  Globodera pallida (Stone) Behrens. Nematoda: Tylenchida: Heteroderidae. Hosts: Solaneceae, especially potato (Solanum tuberosum), tomato (S. lycopersicum) and aubergine (S. melongena). Information is given on the geographical distribution in Europe (Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Faroe Islands, France, Mainland France, Germany, Greece, Crete, Mainland Greece, Hungary, Iceland, Ireland, Italy, Mainland Italy, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Madeira, Mainland Portugal, Romania, Serbia, Slovakia, Spain, Balearic Islands, Canary Islands, Mainland Spain, Sweden, Switzerland, UK, Channel Islands, England and Wales, Northern Ireland, Scotland, Ukraine), Asia (India, Kerala, Tamil Nadu, Iran, Pakistan, Turkey), Africa (Algeria, Tunisia), North America (Canada, Newfoundland, USA, Idaho), Central America and Caribbean (Panama), South America (Argentina, Bolivia, Chile, Colombia, Ecuador, Falkland Islands, Peru, Venezuela), Oceania (New Zealand).

 

 Idaho Infestation (USDA 2013):

In 2006,  Idaho State Department of Agriculture (ISDA) announced the detection of pale cyst nematode (PCN). This was the first detection of the pest in the United States. The nematode cysts were detected during a routine survey of tare soil at an ISDA grading facility in eastern Idaho.

Subsequent 2006 surveying to determine the possible origin and distribution of the pest in Idaho confirmed seven PCN-infested fields totaling 911 acres, all within a one mile radius in Bingham and Bonneville Counties, Idaho.

The PCN-infested fields and an area surrounding the fields were placed under a Federal Domestic Quarantine Order and parallel State Rule in August 2006, establishing restrictions on movement of certain regulated articles from Idaho in order to prevent the spread of PCN.

As a result of continued intensive soil sampling since 2007, an additional twelve PCN-infested fields have been found in Bingham and Bonneville Counties, Idaho. All 19 known infested fields lay within a 5-mile radius. The fields associated with them through shared tenancy, farming practices, equipment, and/or shared borders have been extensively surveyed and regulated.

Since program inception, approximately 50,400 acres have been regulated due to their infestation or association with an infested field.

Noninfested fields have been eligible for federal deregulation following a sequence of soil surveys with no PCN detections.

To date, 37,680 acres have been released from federal regulation; however, some of that acreage was re-regulated due to a new association(s) with an infested field(s).

Currently, 12,744 acres of farmland are regulated, 2,015 acres of which are infested fields.

Eradication treatments in PCN-infested fields have been ongoing since the spring of 2007. Eradication treatments have included methyl bromide fumigation, Telone II fumigation, and planting of biofumigant crops.

Soil testing in infested fields indicates the average viability of eggs within the PCN cysts has declined by more than 99% since eradication treatments began.

To date, eight infested fields have triggered the bioassay stage of evaluating eradication progress when viable eggs were no longer detected in cysts collected from those fields. One of these fields has also successfully completed the bioassay process, enabling it to return to potato production with certain regulatory and survey requirements remaining in place.

Source: USDA, 2013

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Economic Importance:

 A-rated pest in California.

Discovery of G. pallida in Idaho in 2006 caused Japan to ban all fresh US potato imports. Canada, Korea and Mexico banned all fresh potato imports from Idaho, but Mexico and Canada later resumed trade with Idaho farmers.  As of 2010, the Korean and Japanese markets remain closed to Idaho potatoes but negotiations are actively underway to re-gain market access.

On April 19, 2006, officials of USDA’s Animal and Plant Health Inspection Service (APHIS) and the Idaho State Department of Agriculture (ISDA) announced the detection of PCN, a major pest of potato crops. This was the first detection of the pest in the United States. The nematode cysts were detected during a routine survey of tare soil at an ISDA grading facility in eastern Idaho. Subsequent 2006 surveying to determine the possible origin and distribution of the pest in Idaho confirmed seven PCN-infested fields totaling 911 acres, all within a one mile radius in Bingham and Bonneville Counties, Idaho. The PCN-infested fields and an area surrounding the fields were placed under a Federal Domestic Quarantine Order and parallel State Rule in August 2006, establishing restrictions on movement of certain regulated articles from Idaho in order to prevent the spread of PCN.

As a result of continued intensive soil sampling since 2007, an additional twelve PCN-infested fields have been found in Bingham and Bonneville Counties, Idaho. All 19 known infested fields lay within a 5-mile radius. The fields associated with them through shared tenancy, farming practices, equipment, and/or shared borders have been extensively surveyed and regulated.

Since program inception, approximately 50,400 acres have been regulated due to their infestation or association with an infested field. Noninfested fields have been eligible for federal deregulation following a sequence of soil surveys with no PCN detections. To date, 37,680 acres have been released from federal regulation; however, some of that acreage was re-regulated due to a new association(s) with an infested field(s).

Currently, 12,744 acres of farmland are regulated, 2,015 acres of which are infested fields.

Eradication treatments of PCN-infested fields have been ongoing since the spring of 2007. Eradication treatments have included methyl bromide fumigation, Telone II fumigation, and biofumigant plantings. Testing of the top 3 inches of soil in infested fields indicate the average viability of eggs within the PCN cysts have declined by more than 90% since eradication treatments began (USDA-APHIS, 2010, 2013).

 Globodera pallida is progressively competitively replacing G. rostochiensis in Britain (Trudgill et al., 2003) and in Ireland (Devine and Jones, 2003).

 

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Feeding:

Feeding site establishment and development typical of genus.

Nurse cell system is a multinucleate syncytium.

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Hosts:

Very narrow range: potato, tomato, and some weeds.

There are several pathotypes of G. pallida: British B and E, Dutch D.

Pathotype classifications are based on ability of nematode to reproduce on resistant cultivars.

For an extensive list of host plant species and their susceptibility, copy the name

Globodera pallida

select Nemabase and paste the name in the Genus and species box

 

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Life Cycle:

Egg hatch is stimulated by host root diffusate (60-80%) - only about 5% hatch in water. Some eggs do not hatch until subsequent years.

J2 moves into feeder roots, establishes feeding site, and undergoes 3 more molts.

Adult males do not feed. Sex is determined by food supply - males develop in adverse conditions and heavy infestations.

Nematodes reproduce sexually; males are attracted to females by a pheromone sex attractant. Nematodes may mate several times.

Females form cysts containing 200 to 600 eggs, which can stay dormant for up to 30 years while the eggs inside remain viable.

Annual population decline in the absence of a host varies from 18% in cold soils (Scotland) to 50% in warm soils, with an average decline rate about 30% - so population decline follows this pattern: 100-70-50-35-23-etc.

Globodera pallida appears to be more responsive to potato root diffusate than G. rostochiensis.  Consequently, where both species are present, G. pallida reproduces to a greater extent and predominates population levels (Devine and Jones, 2003). The problem is exacerbated when potatoes resistant only to G. rostochiensis are grown.  Available cultivars have only partial resistance to G. pallida and do not prevent its increase. Globodera pallida is progressively replacing G. rostochiensis in Britain (Trudgill et al., 2003). 

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Damage:

The nematodes infest potato roots but do not appear to infest tubers (USDA, 2012).

In Scotland, 1 ton/acre is lost for every 20 eggs/g soil.

Supply of water and nutrients to upper plant is diminished.

Large infestations of G. pallida cause wilting, stunted growth, poor root development, and early plant death. Tuber size is reduced and potato yields may be reduced by 80%.

 

 

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Management:

Crop Sequence:

Continuous cropping of cultivars resistant to G. rostochiensis selects for pathotypes of G. pallida.

Nematicides:

Widely used.

Resistance:

Seeds of three varieties segregating for resistance to two pathotypes of Globodera rostochiensis (Ro1 and Ro2) and two pathotypes of G. pallida (Pa2 and Pa3) have been released by Cornell University and USDA/ARS. The resistance is suitable for North American production.  It was developed in anticipation that pathotypes of G. pallida, which are prevalent in many other potato production areas of the world, are ever introduced into North America. 

The combined resistance in this germplasm is from S. tuberosum ssp andigena and S. vernei. Brodie et al (2000).

Cultivars available in Britain only have partial resistance to G. pallida (Trudgill et al., 2003).

For a list of plant species or cultivars (if any) reported to be immune or to have some level of resistance to this nematode species, copy the name

Globodera pallida

select Nemabase Resistance Search and paste the name in the Genus and species box

Reducing Spread:

As of September 2006, the U.S. Department of Agriculture has issued a potato advisory for a specific area of Southeast Idaho. "People are asked to take precautions when gleaning potatoes missed by the harvester. Agriculture departments have been testing fields in the regulated area. While people are not discouraged from picking potatoes, they should wash off their shoes in between fields to prevent the spread. For more information regarding the regulated area, contact the Potato Cyst Nematode Project Office at 208-351-9857. "

An extensive field sampling program was initiated in Idaho. As of October 2006, seven  infested fields had been identified in Idaho.  The fields are in close proximity to each other.

By the end of 2006, 29,000 soil samples had been tested in a Twin Falls laboratory and at the University of Idaho Nematology Laboratory in Parma. Within the regulated area, 4,000 acres of farm land had been tested.  

The nematode is easily spread by the transport of cysts in soil. This may occur with the movement of soil on farming, construction, and other equipment; infested soil adhering to seed potatoes and other crops; or by transport in river, flood or irrigation water.

Idaho Department of Agriculture applies the following rules regarding Globodera pallida (2008):

INTRASTATE MOVEMENT.

No regulated articles may move within the State of Idaho without complying with the federal regulations, as incorporated by reference in Section 004.01 in this rule. (11-1-07)T

RESTRICTIONS.

01. Movement From a Non-Quarantined Area. Movement of regulated articles from a non-quarantined area is subject to inspection by an inspector. Permits and certifications are not required. (11-1-07)T

02. Movement From a Quarantined Area. Movement of regulated articles from a quarantined area is subject to the provision of Section 02.06.10.015 of this rule. (11-1-07)T

03. Other Restrictions. No potatoes, tomatoes, eggplants or any other known host crops may be planted in the infested fields. Soil must not be moved from the infested fields. Any equipment leaving the infested fields must be sanitized and certified using USDA APHIS approved protocols. (11-1-07)T

04. Seed Potatoes. Seed potatoes may not be grown in a quarantined area. (11-1-07)T

CONDITIONS FOR INTRASTATE OR INTERSTATE MOVEMENT OF REGULATED ARTICLES.

Regulated articles may only be moved intrastate or interstate from a quarantined area by a person under a compliance agreement if accompanied by a certificate or limited permit issued by an inspector in accordance with 7 CFR Part 301 Sections 301.86-4 and 5. (11-1-07)T

INSPECTION, SAMPLING AND TESTING.

In order to accomplish the purposes of this rule, an inspector may enter upon and inspect any public or private premises, lands, means of conveyance, or article of any person within this state, for the purpose of inspecting, surveying, sampling, testing, treating, controlling or destroying any soil, plant or plant material thought to or found to contain or be infested with Potato Cyst Nematode. (11-1-07)T

PENALTIES. Any person violating any of the provisions of these rules will be subject to the penalty provisions of Title 22, Chapter 20, Idaho Code. (11-1-07)T

 

 

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References:

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Copyright 1999 by Howard Ferris.
Revised: December 27, 2013.