A Spatial Analysis of the Potato Cyst Nematode Globodera pallida in Idaho

The potato cyst nematode Globodera pallida is a globally regulated and quarantine potato pest. It was detected for the first time in the United States in the state of Idaho in 2006. A spatial analysis was performed to (i) understand the spatial arrangement of fields infested with G. pallida in southern Idaho using spatial point pattern analysis, and (ii) evaluate the potential threat of G. pallida for entry to new areas using spatial interpolation techniques. Data point locations, cyst numbers and egg viability values for each infested field were collected by USDA-APHIS during 2006 to 2014. Results showed the presence of spatially clustered fields infested with G. pallida (P = 0.003). We determined that the spread of G. pallida grew in diameter from the original center of infestation toward the southwest as an ellipsoidal-shaped cluster. Based on the aggregated spatial pattern of distribution, we determined that G. pallida spread followed a contagion effect scenario, where nearby infested fields contributed to the infestation of new fields, probably through soil contaminated agricultural equipment or tubers. We determined that the presence of G. pallida in southern Idaho is unlikely to be associated with new introductions from outside the state of Idaho. The aggregation pattern of fields infested with G. pallida, with an average of 4,263 cysts/ha and egg viability of 25%, facilitates quarantine activities and confines the propagation of this pest to a small area, which in 2017 was estimated to be 1,233 ha. The tools and methods provided in this study facilitate comprehensive approaches to improve G. pallida control and eradication programs as well as to raise public awareness of the problems surrounding this economically important potato pest.

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Weed Hosts of Globodera pallida from Idaho

Plant Disease ◽

10.1094/pdis-94-7-0918b ◽

2010 ◽

Vol 94 (7) ◽

pp. 918-918 ◽

Cited By ~ 6

Author(s):

R. A. Boydston ◽

H. Mojtahedi ◽

C. Bates ◽

R. Zemetra ◽

C. R. Brown

Keyword(s):

Sandy Loam ◽

The United States ◽

Amaranthus Retroflexus ◽

Cyst Nematode ◽

Russet Burbank ◽

Potato Cyst Nematode ◽

Globodera Pallida ◽

Weed Species ◽

Initial Inoculum ◽

Hairy Nightshade

The potato cyst nematode, Globodera pallida (PCN), a restricted pest in the United States, was first reported in Bingham and Bonneville counties of Idaho in 2006 (1). The U.S. government and Idaho State Department of Agriculture hope to eradicate it from infested fields. Eradicating PCN will require depriving the nematodes of their hosts over a protracted time period. Functional eradication might be achieved with relatively high, proven to be efficacious dosages of soil fumigants. The presence of host weeds of PCN can play a significant role in the success of the eradication program. To determine the host status of common weeds found in potato fields of the Pacific Northwest, host suitability tests were conducted in a secured greenhouse located at the University of Idaho at Moscow. Reproduction of PCN on nine weeds including hairy nightshade (Solanum physalifolium formerly S. sarrachoides) and cutleaf nightshade (S. triflorum) (biotypes from Idaho and Washington), black nightshade (S. nigrum) (Washington biotype), bittersweet nightshade (S. dulcamara) (Idaho biotype), redroot pigweed (Amaranthus retroflexus), kochia (Kochia scoparia), and common lambsquarters (Chenopodium album) were compared with reproduction on Desiree, Russet Burbank (known hosts), and Santé (poor host) potatoes (S. tuberosum). Plants were grown in 10-cm-diameter clay pots containing sandy loam soil previously fumigated with methyl bromide and inoculated with 10 to 150 cysts that were either collected from infested fields or raised in the secured greenhouse (ample diapause period elapsed). Treatments were replicated five times and each trial lasted 3 months. Cysts were extracted from soil with a Fenwick can, and the reproductive factor (RF = final cyst count ÷ initial inoculum) was determined. While both biotypes of hairy nightshade were suitable hosts of PCN (161–668 ÷ 150; RF = >1), cutleaf biotypes, black, and bittersweet nightshades were poor hosts (1–108 ÷ 150; RF = <1). Russet Burbank (77 ÷ 40; RF = 1.9) and Desiree (21–119 ÷ 75; RF = >1) proved to be suitable hosts and Santé (1–20 ÷ 150; RF = <1) a poor host of Idaho PCN. Although some cysts were recovered from pots containing the remaining weed species, they may have been part of the original inoculum. The significance of nightshade species (whether suitable or poor hosts) in eradication of potato cyst nematode from infested fields cannot be overemphasized. Reference: (1) A. M. Skantar et al. J. Nematol. 39:133, 2007.

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A Spatiotemporal Analysis and Dispersal Patterns of the Potato Cyst Nematode Globodera pallida in Idaho

Phytopathology ◽

10.1094/phyto-04-19-0113-r ◽

2020 ◽

Vol 110 (2) ◽

pp. 379-392 ◽

Cited By ~ 1

Author(s):

J. B. Contina ◽

L. M. Dandurand ◽

G. R. Knudsen

Keyword(s):

Cover Crops ◽

Simulation Models ◽

The United States ◽

Cyst Nematode ◽

Potato Cyst Nematode ◽

Globodera Pallida ◽

Spatiotemporal Pattern ◽

Dispersal Pattern ◽

Dispersal Patterns ◽

Nematode Reproduction

The potato cyst nematode Globodera pallida is a globally regulated potato pest. It was detected for the first time in the United States in the state of Idaho in 2006, and as of February 2019, the infestation is limited to 1,326 hectares. G. pallida is a specialized obligate sedentary endoparasite that can survive in the soil for up to 30 years in the absence of its potato host. In highly infested fields, the nematode can reduce tuber yields up to 80% and is spread mainly through the movement of soil, tubers, or farm equipment. The objectives of this study were to describe the spatiotemporal pattern of G. pallida in infested fields and model its dispersal patterns in southeastern Idaho. We used geostatistical tools and simulation models for precise mapping and to describe the relationships between G. pallida incidence and the spatial configurations. We found that the nematode is spatially clustered and prevalent around edges of fields, and its dispersal pattern followed the direction of cultivation. We found that the absence of potato in an infested field significantly reduced the number of cysts sampled each year subsequent to the initial delimitation sampling in 2007. Phytosanitary measures prohibiting the growth of potato contributed to stopping nematode reproduction, and the use of chemical fumigants and biofumigant cover crops contributed to a significant reduction in egg viability. We observed a process of a nonlinear decline in the prevalence of cysts as the distance separation from the primary infestation focus increased. A power law model was used to fit G. pallida dispersal capabilities. This study contributed to describing G. pallida infestation for Idaho. The goal of this study is to provide information on the spatial pattern and landscape ecology of G. pallida in Idaho for policy makers, industry, and researchers as well as facilitate common understandings on the challenges and opportunities for controlling this pest in Idaho.

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An investigation of resistance to the white potato cyst-nematode

The Journal of Agricultural Science ◽

10.1017/s0021859600030094 ◽

1982 ◽

Vol 99 (2) ◽

pp. 325-328 ◽

Cited By ~ 19

Author(s):

M. F. B. Dale ◽

M. S. Phillips

Keyword(s):

Solanum Tuberosum ◽

Major Gene ◽

Cyst Nematode ◽

Potato Cyst Nematode ◽

Globodera Pallida ◽

Screening Methods ◽

Inheritance Of Resistance ◽

White Potato

SUMMARYThe inheritance of resistance to Globodera pallida was studied in seedling progenies derived from Solanum tuberosum ssp. andigena CPC 2802 (H3) and S. vernei and compared with resistance to G. rostochiensis derived from S. tuberosum ssp. andigena CPC 1673(H1). The resistance of CPC 2802 was originally thought to be due to a major gene (H3), but results presented here demonstrate that it and that derived from S. vernei are inherited in a similar manner quite distinct from the major gene inheritance from CPC 1673 (HI). It is concluded that the resistances derived from CPC 2802 and S. vernei are both polygenic in nature. These findings are discussed in relation to breeding policy and screening methods.

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The ability of rhizosphere bacteria isolated from nematode host and non-host plants to influence the hatch in vitro of the two potato cyst nematode species, Globodera rostochiensis and G. pallida

Nematology ◽

10.1163/1568541042360528 ◽

2004 ◽

Vol 6 (3) ◽

pp. 375-387 ◽

Cited By ~ 5

Author(s):

N. Aileen Ryan ◽

Peter Jones

Keyword(s):

Sugar Beet ◽

Host Plant ◽

Host Plants ◽

Nematode Species ◽

Cyst Nematode ◽

Potato Cyst Nematode ◽

Globodera Pallida ◽

Bacterial Isolates ◽

Bacillus Spp

AbstractSeventy bacteria, isolated from the rhizosphere of the potato cyst nematode (PCN) host plant, potato, were cultured in the presence and absence of potato root leachate (PRL) and the resultant culture filtrates were analysed for their ability to affect the hatch in vitro of the two PCN species. Of the isolates tested, nine had a significant effect on PCN hatch. Six affected Globodera pallida hatch and three affected G. rostochiensis hatch. Five of the isolates significantly increased hatch only when cultured in the presence of PRL. Three of the isolates decreased PCN hatch significantly in PRL. Only one isolate increased hatch significantly in the absence of PRL. No isolate affected the hatch of both species. Six of the nine isolates that significantly affected PCN hatch had been pre-selected by culturing on PRL. Bacterial isolates from PCN non-hosts (14 from wheat, 17 from sugar beet) were also tested for hatching activity. The principal effect of the hatch-active isolates from the PCN non-host plants was to increase PCN hatch in the presence of PRL. In contrast to the host bacteria results, the isolates from non-host plants affected only G. rostochiensis hatch (three wheat isolates and four sugar beet isolates significantly increased G. rostochiensis hatch); no such isolate affected G. pallida hatch significantly in the presence of PRL. Ten isolates (32%) from non-host plants had the ability to increase significantly the hatch of PCN in the absence of PRL (eight of these affected G. rostochiensis hatch and four affected G. pallida hatch), compared to only one bacterial isolate (1%) from a host plant. The majority of the isolates from non-hosts produced PCN species-specific effects, as with the bacteria isolated from potatoes, although two wheat isolates increased the hatch of both species significantly in the absence of PRL. Of 20 hatch-active bacterial isolates (from all three plants) identified, 70% were Bacillus spp. Other genera identified were Arthrobacter , Acinetobacter and Staphylococcus .

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The Genomic Impact of Selection for Virulence against Resistance in the Potato Cyst Nematode, Globodera pallida

Genes ◽

10.3390/genes11121429 ◽

2020 ◽

Vol 11 (12) ◽

pp. 1429

Author(s):

Kyriakos Varypatakis ◽

Pierre-Yves Véronneau ◽

Peter Thorpe ◽

Peter J. A. Cock ◽

Joanne Tze-Yin Lim ◽

...

Keyword(s):

Potato Industry ◽

Cyst Nematode ◽

Potato Cyst Nematode ◽

Globodera Pallida ◽

Genomic Islands ◽

Natural Resistance ◽

Management Approach ◽

Resistance Sources ◽

Breeding Programmes ◽

Avr Genes

Although the use of natural resistance is the most effective management approach against the potato cyst nematode (PCN) Globodera pallida, the existence of pathotypes with different virulence characteristics constitutes a constraint towards this goal. Two resistance sources, GpaV (from Solanum vernei) and H3 from S. tuberosum ssp. andigena CPC2802 (from the Commonwealth Potato Collection) are widely used in potato breeding programmes in European potato industry. However, the use of resistant cultivars may drive strong selection towards virulence, which allows the increase in frequency of virulent alleles in the population and therefore, the emergence of highly virulent nematode lineages. This study aimed to identify Avirulence (Avr) genes in G. pallida populations selected for virulence on the above resistance sources, and the genomic impact of selection processes on the nematode. The selection drive in the populations was found to be specific to their genetic background. At the genomic level, 11 genes were found that represent candidate Avr genes. Most of the variant calls determining selection were associated with H3-selected populations, while many of them seem to be organised in genomic islands facilitating selection evolution. These phenotypic and genomic findings combined with histological studies performed revealed potential mechanisms underlying selection in G. pallida.

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Studies On an Artificially Fragmented Population of Potato Cyst Nematode Globodera Pallida

Nematologica ◽

10.1163/005725998x00069 ◽

1998 ◽

Vol 44 (6) ◽

pp. 655-666 ◽

Cited By ~ 5

Author(s):

B.E. Harrower ◽

A. Ploeg ◽

V.C. Blok ◽

M.S. Phillips

Keyword(s):

Cyst Nematode ◽

Potato Cyst Nematode ◽

Globodera Pallida ◽

Fragmented Population

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Isolation, formulation and antagonistic activity of rhizobacteria toward the potato cyst nematode Globodera pallida

Soil Biology and Biochemistry ◽

10.1016/0038-0717(92)90075-9 ◽

1992 ◽

Vol 24 (6) ◽

pp. 521-526 ◽

Cited By ~ 38

Author(s):

J. Racke ◽

R.A. Sikora

Keyword(s):

Antagonistic Activity ◽

Cyst Nematode ◽

Potato Cyst Nematode ◽

Globodera Pallida

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First Report of the Pale Potato Cyst Nematode Globodera pallida from Bosnia and Herzegovina

Plant Disease ◽

10.1094/pdis-07-13-0739-pdn ◽

2014 ◽

Vol 98 (4) ◽

pp. 575-575 ◽

Cited By ~ 1

Author(s):

B. Nježić ◽

B. Gerič Stare ◽

S. Širca ◽

N. Grujić

Keyword(s):

Bosnia And Herzegovina ◽

Potato Production ◽

Cyst Nematode ◽

Soil Samples ◽

Potato Cyst Nematode ◽

Globodera Pallida ◽

Economic Losses ◽

Cyst Nematodes ◽

Seed Potatoes ◽

Infested Field

Potato cyst nematodes (PCN), the golden cyst nematode Globodera rostochiensis (Woll.) Bahrens, and the pale potato cyst nematode G. pallida (Stone) stand out by their remarkable and efficient parasitic adaptations causing high economic losses in potato production worldwide. They are A2 quarantine pests in EPPO countries as well as in Bosnia and Herzegovina. Up to now, only G. rostochiensis was reported from Bosnia and Herzegovina in 2011 (1). A systematic survey on the presence of PCN on entire territory of Bosnia and Herzegovina started in 2011. During the PCN survey, each year 120 soil samples of 1.5 liters were collected in the Republic of Srpska, one of the two entities of Bosnia and Herzegovina. The samples were collected by soil auger 10 cm in length with a diameter of 1.5 cm consisting of 100 cores. Entire samples were processed by Seinhorst elutriator (4). In autumn of 2012, PCN viable cysts were found in two soil samples originating from one field. From one sample, 12 cysts were extracted, and 2 from another sample. The morphology of cysts and second stage juveniles and molecular analysis established the identity of this species as pale cyst nematode G. pallida (3). In addition, the sequencing of the ribosomal DNA region revealed unequivocal similarity to G. pallida (GenBank Accession No. HF968449), while PCR-RFLP analysis (2) showed European type of G. pallida. The infested field is located in Rogatica, 70 km east of Sarajevo, which is one of the main seed and potato production areas in Bosnia and Herzegovina. The field history revealed that farm-propagated, farm-saved seed potatoes could spread the nematodes to other fields as well. Therefore, 26 additional samples were taken from the fields that belong to the infested field owner and the surrounding fields, but no cysts were found in additional samples. To determine infestation focus and its size, the infested field (1.1 ha) was divided into 46 plots (25 × 10 m) and resampled by taking samples of 60 cores per plot. The detailed sampling of the field revealed a high infestation of 1 cyst per gram of soil in the infestation focus. The high infestation level and the propagation of farm-own seed potatoes suggest that the introduction of G. pallida might have occurred several years ago, probably with imported seed potatoes. The infested field was subjected to the phytosanitary measure of banning potato production for a period of 6 years with the possibility of its prolongation, if cysts with live content are found afterward. It is expected that the nematode is present in other fields due to the farmer's practices of propagating farm-saved seed potatoes and deficient field machinery hygiene. Therefore, the whole area will be intensively monitored for the presence of PCN in the future. An adequate pest management plan will be prepared after PCN pathotype identification. To our knowledge, only one field was found infested with G. pallida during the 3-year PCN survey in Bosnia and Herzegovina. Strict phytosanitary measures for preventing further PCN introductions and spreading should be intensified. References: (1) I. Ostojić et al. Plant Dis. 95:883, 2011. (2) S. Širca et al. Phytopathol. Mediterr. 49:361, 2010. (3) A. M. Skantar et al. J. Nematol. 39:133, 2007. (4) J. van Bezooijen. Methods and Techniques for Nematology, Wageningen University, 2006.

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