Will the Globodera pallida epidemic signal the end of the seed potato industry in Scotland?

2021 ◽  
pp. 333-339
Author(s):  
Jon Pickup
Keyword(s):  
Potato Cultivar ◽  
Population Level ◽  
Potato Production ◽  
Potato Industry ◽  
Globodera Pallida ◽  
Future Research ◽  
Potato Cyst Nematodes ◽  
Cyst Nematodes ◽  
Pests And Diseases ◽  
Management Optimization

Abstract Among pests and diseases of potatoes, British potato growers consider potato cyst nematodes (PCN: Globodera pallida and G. rostochiensis) to cause the most damage. By feeding on the roots, PCN stunt plant growth, adversely affecting yields, tuber size and skin finish. Yield losses depend on the population level of the PCN in the soil, the soil type and the tolerance of the potato cultivar to the nematode damage. The increase in G. pallida has been most marked in the county of Angus, traditionally the part of Scotland most intensively cultivated with potatoes. The incidence of G. pallida in Angus is estimated as 9% of the area used for potato production, accounting for 68% of the total area of G. pallida infested land in Scotland. This chapter discusses the economic importance, host range, distribution, symptoms of damage, biology and life cycle, recommended integrated nematode management, and management optimization of PCN in Scotland. Future research requirements are also mentioned.

Effector gene vap1-based DGGE fingerprinting to assess variation within and among Globodera species and populations

Nematology ◽  
2019 ◽  
Vol 21 (10) ◽  
pp. 1023-1036
Author(s):  
Rasha Haj Nuaima ◽  
James M. Mwangi ◽  
Sebastian Kiewnick ◽  
Holger Heuer
Keyword(s):  
Temporal Change ◽  
Allelic Variation ◽  
Management Strategies ◽  
Population Level ◽  
Globodera Pallida ◽  
Potato Cyst Nematodes ◽  
Gene Variants ◽  
Adaptive Potential ◽  
Cyst Nematodes ◽  
Effector Gene

Summary Population-level genetic tools to study the epidemiology of potato cyst nematodes (PCN) are needed to evaluate their adaptive potential and validate management strategies. The effector gene vap1 is essential in early infection by PCN. We expected high allelic variation due to diversifying selection. A technique was developed specifically to amplify vap1 fragments of PCN, and electrophoretically separate variants in a denaturing gradient (DGGE). Sequenced gene variants differed in intron as well as exon regions. Siblings were more similar in vap1 pattern than juveniles from different cysts. Nearly all juveniles analysed had unique patterns with up to ten or five vap1 variants for Globodera pallida or G. rostochiensis, respectively. Patterns differed significantly among populations, with similarities increasing from between-species, within-species to within-pathotype comparisons. In conclusion, the method is suitable to determine the similarity of heterogeneous PCN populations for studies on their temporal change and spread.

scholarly journals Taxonomy, Morphological and Molecular Identification of the Potato Cyst Nematodes, Globodera pallida and G. rostochiensis

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 184
Author(s):  
John Wainer ◽  
Quang Dinh
Keyword(s):  
Life Cycle ◽  
Molecular Identification ◽  
Soil Sampling ◽  
Globodera Pallida ◽  
Potato Cyst Nematodes ◽  
Cyst Nematodes ◽  
Primary Focus

The scope of this paper is limited to the taxonomy, detection, and reliable morphological and molecular identification of the potato cyst nematodes (PCN) Globodera pallida and G. rostochiensis. It describes the nomenclature, hosts, life cycle, pathotypes, and symptoms of the two species. It also provides detailed instructions for soil sampling and extraction of cysts from soil. The primary focus of the paper is the presentation of accurate and effective methods to identify the two principal PCN species.

scholarly journals Occurrence and molecular characterization of cyst nematode species (Globodera spp.) associated with potato crops in Colombia

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0241256
Author(s):  
Daniela Vallejo ◽  
Diego A. Rojas ◽  
John A. Martinez ◽  
Sergio Marchant ◽  
Claudia M. Holguin ◽  
...  
Keyword(s):  
Management Strategies ◽  
Nematode Species ◽  
Globodera Pallida ◽  
Rrna Gene ◽  
Potato Cyst Nematodes ◽  
28S Rrna ◽  
Cyst Nematodes ◽  
Nucleotide Substitutions ◽  
Internal Transcribed Spacer Region ◽  
The Status

Potato cyst nematodes (PCN) from the genus Globodera spp. cause major losses in the potato (Solanum tuberosum) industry worldwide. Despite their importance, at present little is known about the status of this plant pathogen in cultivated potatoes in Colombia. In this study, a total of 589 samples collected from 75 geographic localities in nine potato producing regions of Colombia (Cundinamarca, Boyacá, Antioquia, Nariño, Santander, Norte de Santander, Tolima, Caldas and Cauca) were assayed for the presence of potato cyst nematodes. Fifty-seven percent of samples tested positive for PCN. Based on phylogenetic analysis of the internal transcribed spacer region (ITS1-5.8S-ITS2) of the rRNA gene and D2-D3 expansion segments of the 28S rRNA gene, all populations but one were identified as Globodera pallida. Sequences of G. pallida from Colombia formed a monophyletic group closely related to Peruvian populations, with the lowest average number of nucleotide substitutions per site (Dxy = 0.002) and net nucleotide substitutions per site (Da = 0.001), when compared to G. pallida populations from Europe, South and North America. A single sample formed a well-supported subclade along with G. rostochiensis and G. tabacum from Japan, USA and Argentina. To our knowledge this is the first comprehensive survey of Globodera populations from Colombia that includes genetic data. Our findings on species diversity and phylogenetic relationships of Globodera populations from Colombia may help elucidate the status and distribution of Globodera species, and lead to the development of accurate management strategies for the potato cyst nematodes.

scholarly journals Study of European and Czech populations of potato cyst nematodes (Globodera rostochiensis and G. pallida) by RAPD method

2011 ◽  
Vol 50 (No. 2) ◽  
pp. 70-74 ◽  
Author(s):  
P. Sedlák ◽  
M. Melounová ◽  
S. Skupinová ◽  
P. Vejl ◽  
J. Domkářová
Keyword(s):  
Animal Species ◽  
Molecular Genetic ◽  
Globodera Rostochiensis ◽  
Globodera Pallida ◽  
Genetic Identification ◽  
Potato Cyst Nematodes ◽  
Cyst Nematodes ◽  
Genetic Dissimilarity ◽  
Solanaceous Plants ◽  
Molecular Genetic Identification

Potato cyst nematodes (PCN) are the big problem in worldwide planting of potatoes and another Solanaceous plants. Identification of individual pathotypes according to international scheme is very demanding but a very important part of the phytosanitary process to control these pests. Molecular genetic identification of different plant and animal species or individuals is a very interesting way at the present time and let’s hope that it will be important in future. This report presents results of the RAPD study of nine different real PCN populations. There were five Globodera rostochiensis populations and four G. pallida populations. Pathotypes Ro2, Ro2/3, Ro4, Ro5, Pa2 and Pa3 were from European populations; population Ro1 and X were of Czech provenance. Genetics variable of these populations was described by a set of six decameric primers (OPA 07, OPG 03, OPG 05, OPG 08, OPG 10 and OPG 13). Genetic dissimilarity was by Gel Manager for Windows evaluated. Detectable differences behind all populations were found and the dendrogram was compiled. The unknown population X was sorted into group of Globodera pallida species subgroup of Pa2 consequently.

scholarly journals Variability of D2/D3 segment sequences of several populations and pathotypes of potato cyst nematodes (Globodera rostochiensis, Globodera pallida)

2010 ◽  
Vol 46 (No. 4) ◽  
pp. 171-180 ◽  
Author(s):  
O. Douda ◽  
M. Zouhar ◽  
E. Nováková ◽  
J. Mazáková ◽  
P. Ryšánek
Keyword(s):  
Dna Analysis ◽  
Pcr Amplification ◽  
Globodera Rostochiensis ◽  
Globodera Pallida ◽  
Potato Cyst Nematodes ◽  
Cyst Nematodes ◽  
Routine Diagnostics ◽  
Pair Comparisons ◽  
Single Fragment ◽  
Direct Management

Potato cyst nematodes (Globodera rostochiensis, Globodera pallida) remain a key pest in the main potato growing regions of the Czech Republic. Due to difficult direct management and presence of diverse pathotypes attacking different potato cultivars the rapid and reliable diagnostics is of crucial importance. Currently, efforts are aimed at a description of different pathotypes based on DNA analysis. The main objective of this study was to evaluate the homogeneity of sequences of D2/D3 segments of the 28S rDNA gene obtained from 3 populations of G. rostochiensis and 5 populations of G. pallida and estimate their value for diagnostic purposes. PCR amplification yielded a single fragment of the length of 700 bp approximately in all populations. The alignment score of the vast majority of all pair comparisons of G. rostochiensis and G. pallida populations varied from 98 to 99. In total 14 point deletions and 3 substitutions were observed. The variability of D2/D3 segments of potato cyst nematodes is rather low and this DNA region can be used for diagnostics on a species level because more differences were found after comparing with G. tabacum and G. millefolii sequences obtained from Gene Bank; however the applicability of D2/D3 sequences to routine diagnostics of potato cyst nematodes could be complicated by its similarity to corresponding sequences of the nematode G. artemisiae.

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

Plant Disease ◽  
2014 ◽  
Vol 98 (4) ◽  
pp. 575-575 ◽  
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.

Quantification of viable eggs of the potato cyst nematodes (Globodera spp.) using either trehalose or RNA-specific Real-Time PCR

Nematology ◽  
2014 ◽  
Vol 16 (10) ◽  
pp. 1219-1232 ◽  
Author(s):  
Johanna E. Beniers ◽  
Thomas H. Been ◽  
Odette Mendes ◽  
Marga P.E. van Gent-Pelzer ◽  
Theo A.J. van der Lee
Keyword(s):  
Real Time ◽  
Visual Inspection ◽  
Membrane Integrity ◽  
Globodera Pallida ◽  
Potato Cyst Nematodes ◽  
Original Sample ◽  
Rt Pcr ◽  
Cyst Nematodes ◽  
Pcr Assay ◽  
Field Samples

Two novel methods for the quantitative estimation of the number of viable eggs of the potato cyst nematodes (Globodera pallida and G. rostochiensis) were tested and compared with visual inspection. One is based on the loss of membrane integrity upon death and uses trehalose (a disaccharide) as a marker, the second test exploits the rapid degeneration of mRNA upon decease with a RNA-specific Real-Time Polymerase Chain Reaction (RT-PCR) assay. The viability of eggs in suspensions with different numbers of eggs was determined morphologically and was compared with both trehalose and elongation-factor-1-alpha (EF1α) mRNA measurements. The trehalose assay provided results that were close to those of the visual assessment using a microscope but only when samples contained low numbers of eggs. The lowest detectable value is 1.1 egg in the original sample and small differences in the number of viable eggs can be detected. Unfortunately, trehalose measurements reached a saturation limit at 1 cyst 10 μl−1; therefore, samples with nematode numbers above 262 eggs have to be diluted. The presence of dead cysts did not have a negative effect on the trehalose measurements. However, the use of egg suspensions instead of encysted eggs improved both the trehalose absorbance and the reliability of the measurements. When cysts were exposed to a treatment with allylisothiocyanate, the trehalose measurement detected the presence of more viable eggs than a hatching assay. The RT-PCR assay required a minimum of 30 eggs before detection occurred but can detect up to 8000 eggs in a 25 μl sample, which is an advantage when samples with high PCN infestations have to be processed. However, the confidence intervals (CI) of the RT-PCR assay are larger than those of the trehalose assay, which results in a high variation of single measurements. For example, at a density of 210 eggs in the original sample the 95% CI for the trehalose assay covers 191-228 eggs, and the 95% CI for the RT-PCR assay for G. pallida lies between 73 and 602 eggs and for G. rostochiensis between 59 and 745 eggs. Trials with field samples using both methods supported the laboratory tests. 95% of the field samples tested with the trehalose assay lie within the CI of the standard curve compared to 58% of the RT-PCR tested samples for G. pallida. The measurements of the field samples of G. pallida and G. rostochiensis populations using both methods resulted in larger numbers of viable eggs being detected compared to a hatching test. Neither of the investigated methods in their current state of development is optimal for use as a substitute for the visual inspection used in monitoring labs. The variance of the RT-PCR assay is too high if used for quantitative monitoring; the density range of eggs that can be detected using the trehalose assay is too small.

The effect of mycorrhization of potato roots on the hatching chemicals active towards the potato cyst nematodes, Globodera pallida and G. rostochiensis

Nematology ◽  
2004 ◽  
Vol 6 (3) ◽  
pp. 335-342 ◽  
Author(s):  
Aileen Ryan ◽  
Peter Jones
Keyword(s):  
Liquid Chromatography ◽  
Cyst Nematode ◽  
Globodera Pallida ◽  
Potato Cyst Nematodes ◽  
Cyst Nematodes ◽  
Potato Root ◽  
Potato Plants ◽  
Nitrogen Concentrations ◽  
Mycorrhizal Plants ◽  
Species Specific

AbstractComparison of potato root leachates (PRL) collected from the roots of mycorrhizal (using the mixed-isolate inoculum, Vaminoc) and non-mycorrhizal potato cv. Golden Wonder confirmed that mycorrhization caused a significant increase in hatching activity towards Globodera pallida but not G. rostochiensis. After fractionating the leachates by low pressure molecular exclusion/anion exchange liquid chromatography, several potato cyst nematode (PCN) species-specific hatching factors (HF) were found only in PRL from mycorrhizal plants. Leachate from mycorrhizal plants also contained more of several of those HF common to PRL from both mycorrhizal and non-mycorrhizal plants. Significantly more hatching factor stimulants (HS) active towards both PCN species were found in the PRL from mycorrhizal than from non-mycorrhizal plants; several HS were specific to mycorrhizal plants. No differences (quantitative or qualitative) were observed in hatching inhibitor (HI) levels between PRL from mycorrhizal and non-mycorrhizal plants. Mycorrhization of potato plants resulted in a 20% increase in carbon but a 48% decrease in nitrogen concentrations of the PRL compared to that from the non-mycorrhizal plants.

The effects of α-solanine and zinc sulphate on the behaviour of potato cyst nematodes Globodera rostochiensis and G. pallida

Nematology ◽  
2015 ◽  
Vol 17 (9) ◽  
pp. 1105-1111 ◽  
Author(s):  
Vincas Būda ◽  
Rasa Čepulytė-Rakauskienė
Keyword(s):  
Host Plants ◽  
Zinc Sulphate ◽  
Globodera Rostochiensis ◽  
Globodera Pallida ◽  
The Other ◽  
Potato Cyst Nematodes ◽  
Water Control ◽  
Cyst Nematodes ◽  
Second Stage ◽  
Testing Period

Two behavioural assays were carried out: one on the attraction of potato cyst nematodes (PCN), Globodera rostochiensis and G. pallida, to solanaceae-specific secondary metabolite α-solanine, the other on the effect of ZnSO4 (a compound known to suppress chemoreceptors). The first assay demonstrated that α-solanine was attractive to second-stage juveniles (J2) of PCN; G. pallida was attracted to concentrations of 10−4 M and 10−5 M, whereas G. rostochiensis was attracted to 10−5 M. Globodera pallida reacted faster than G. rostochiensis to the same concentration of α-solanine. As α-solanine is produced by host plants of PCN, this compound is attributed to kairomones. The response to α-solanine of nematodes pre-exposed to a 3 mM ZnSO4 solution was significantly suppressed compared to that of water control. The effect was observed throughout the whole testing period (30 min). This is the first evidence that both α-solanine and ZnSO4 can affect the behaviour of hatched J2 of PCN.

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