scholarly journals Resisting Potato Cyst Nematodes With Resistance

2021 ◽  
Vol 12 ◽  
Author(s):  
Ulrike Gartner ◽  
Ingo Hein ◽  
Lynn H. Brown ◽  
Xinwei Chen ◽  
Sophie Mantelin ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Integrated Management ◽  
Resistant Variety ◽  
Potato Cyst Nematodes ◽  
Concerted Effort ◽  
Cyst Nematodes ◽  
Worldwide Distribution ◽  
Resistant Varieties ◽  
Breeding Programmes ◽  
Effective Component

Potato cyst nematodes (PCN) are economically important pests with a worldwide distribution in all temperate regions where potatoes are grown. Because above ground symptoms are non-specific, and detection of cysts in the soil is determined by the intensity of sampling, infestations are frequently spread before they are recognised. PCN cysts are resilient and persistent; their cargo of eggs can remain viable for over two decades, and thus once introduced PCN are very difficult to eradicate. Various control methods have been proposed, with resistant varieties being a key environmentally friendly and effective component of an integrated management programme. Wild and landrace relatives of cultivated potato have provided a source of PCN resistance genes that have been used in breeding programmes with varying levels of success. Producing a PCN resistant variety requires concerted effort over many years before it reaches what can be the biggest hurdle—commercial acceptance. Recent advances in potato genomics have provided tools to rapidly map resistance genes and to develop molecular markers to aid selection during breeding. This review will focus on the translation of these opportunities into durably PCN resistant varieties.

scholarly journals Soybean cyst nematodes: a destructive threat to soybean production in China

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Deliang Peng ◽  
Ru Jiang ◽  
Huan Peng ◽  
Shiming Liu
Keyword(s):  
Resistance Genes ◽  
Soybean Cyst Nematode ◽  
Integrated Management ◽  
Resistance Breeding ◽  
Research Progress ◽  
Cyst Nematodes ◽  
Soybean Production ◽  
Specific Pcr ◽  
Soybean Cyst Nematodes ◽  
Soybean Resistance

AbstractSoybean cyst nematode (SCN), Heterodera glycines, is one of the most important pests in soybean production worldwide. In China, 11 different races of SCN, including a newly identified race ‘X12’ with super-virulence, have been surveyed and found to be distributed in 22 provinces. Among them, races 1, 3 and 4 are dominant in the two principal soybean-producing areas, Northeast China and Huanghuaihai Valley, causing over 120 million dollars of annual yield loss. Rapid and reliable PCR-based approaches have been developed for the molecular diagnosis of SCN. High-throughput methods for the identification of soybean resistance against SCN are also developed with specific single nucleotide polymorphism markers by using Kompetitive Allele Specific PCR technology. Over 10,000 soybean germplasm sources were evaluated for their SCN resistance, and 28 SCN-resistant soybean accessions were selected to construct an applied core collection, which has been used for soybean breeding in China. Recently, the genome sequences of SCN and soybean are publically available, and two major SCN-resistant genes (rhg1 and Rhg4) have been identified in soybean, which greatly facilitate the researches on SCN virulence and soybean resistance, and also soybean resistance breeding against SCN. However, the management of SCN still faces many bottlenecks, for instance, the single resistance genes in soybean cultivars can be easily overcome by new SCN races; the identified resistance genes are inadequate to meet the practical breeding needs; and our understanding of the mechanisms of SCN virulence and soybean resistance to SCN are limited. SCN is a destructive threat to soybean production throughout the world including China. In this review, the major progress on soybean SCN is summarized, mainly focusing on the recent research progress in SCN, soybean resistance to SCN and integrated management of SCN in China, and aiming at a better understanding of the current SCN research status and prospects for future work.

scholarly journals Preliminary Results Concerning Marker Assisted Selection for Potato Resistance to Phytophthora Infestans

1970 ◽  
Vol 66 (1) ◽  
Author(s):  
Constantin BOTEZ ◽  
Doru PAMFIL ◽  
Abdelmoumen TAOUTAOU ◽  
Erika BALAZS ◽  
Paul RAICA
Keyword(s):  
Molecular Markers ◽  
Late Blight ◽  
Resistance Genes ◽  
Marker Assisted Selection ◽  
Resistant Variety ◽  
Polymorphic Band ◽  
Amplification Product ◽  
Causal Organism ◽  
Resistant Varieties ◽  
Potato Resistance

Phytophtora infestans, the causal organism of late blight, is the most important fungal pathogen of potato. Utilization of resistant variety is the most important strategy of potato late blight control. For creating new resistant varieties Marker Assisted Selection significantly increase the efficiency of this process. RAPD markers offer the advantage that it requires no preliminary information concerning the DNA sequence of the resistance genes or about expression product of these genes. But in this case molecular markers, defined by a certain polymorphism, have to be attributed to resistance genes by a genetic analysis. The simplest method, rely on co segregation or constantly presence of a polymorphic band in the resistant forms that is absent in the susceptible forms. To achieve that two groups of potato accessions originated from USA and Brasov, Romania, were used, represented of resistant differential lines with known R genes. From the seven primers used some gave amplification product only in resistant differential lines but no in sensitive one, amplification product that could be considered as candidate for molecular markers of resistant genes usable for Marker Assisted Selection of potato resistant to P. infestans.

scholarly journals Assessment of resistance of potato hybrids from the Russian Potato Research Center’s collection to Globodera rostochiensis

2021 ◽  
Vol 941 (1) ◽  
pp. 012028
Author(s):  
A K Koroleva ◽  
A B Sivolapova ◽  
M S Voinova ◽  
A S Ivanova ◽  
A A Meleshin ◽  
...  
Keyword(s):  
Molecular Markers ◽  
Globodera Rostochiensis ◽  
Potato Research ◽  
Globodera Pallida ◽  
Potato Cyst Nematodes ◽  
Cyst Nematodes ◽  
Gene Markers ◽  
Resistant Varieties ◽  
The Creation ◽  
Almost All

Abstract The potato cyst nematodes (PCN) Globodera rostochiensis and Globodera pallida are the most common pests feeding on potato roots. These pests have an aggressive distribution dynamic and bring a lot of damage to yield. The study presents results of comprehensively test new potato genotypes for resistance to the golden potato nematode (Globodera rostochiensis), for its further use in breeding and the creation of economically valuable resistant varieties. Almost half of the samples showed laboratory resistance to golden potato nematode, the rest were susceptible. 26 samples have shown the presence of two molecular markers (N146, N19), indicating the presence of H1 gene. Almost all samples showed a correspondence between laboratory resistance and the presence of H1 gene markers.

An evaluation of the implications of virulence in non-European populations of Globodera pallida and G. rostochiensis for potato cultivation in Europe

Nematology ◽  
2012 ◽  
Vol 14 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Sue Hockland ◽  
Björn Niere ◽  
Eric Grenier ◽  
Vivian Blok ◽  
Mark Phillips ◽  
...  
Keyword(s):  
Genetic Variability ◽  
South America ◽  
Integrated Management ◽  
Nematode Species ◽  
Globodera Pallida ◽  
Plant Health ◽  
Potato Cyst Nematodes ◽  
Cyst Nematodes ◽  
Resistant Cultivars ◽  
Council Directive

The potato cyst nematodes Globodera pallida and G. rostochiensis are listed in the EU Plant Health Directive 2000/29/EC and are also subject to the new EU Council Directive 2007/33/EC on the control of potato cyst nematodes, requiring unilateral suppression of these pests in Europe. At the same time there is also pressure to increase world trade in potatoes. Such pressure has to be balanced by the risks involved in the associated spread of these pests and subsequent problems in management. Populations of the potato cyst nematodes from outside Europe, in particular South America, which is considered the origin of G. pallida and G. rostochiensis, pose a risk to those European countries where limited genetic variability of these nematode species has been recorded. The development and usage of resistant cultivars under such conditions has formed a pivotal role in integrated management programmes in Europe. Molecular studies have shown that populations of G. pallida and G. rostochiensis from South America have a different genetic composition from those in Europe. The introduction of such populations would pose a threat to the use of resistant cultivars as a major tool in reducing the potential spread and damage caused by these species. At present, an inability to link precisely genetic variability to the virulence characteristics of a specific nematode population, and quickly identify the virulence status of intercepted populations for inspection purposes, strengthens the case for using plant health legislation to prevent their introduction.

scholarly journals Optimizing Trehalose-Based Quantification of Live Eggs in Potato Cyst Nematodes (Globodera rostochiensis and G. pallida)

Plant Disease ◽  
2015 ◽  
Vol 99 (7) ◽  
pp. 947-953 ◽  
Author(s):  
N. Ebrahimi ◽  
N. Viaene ◽  
M. Moens
Keyword(s):  
Integrated Management ◽  
Visual Assessment ◽  
Assessment Method ◽  
Globodera Rostochiensis ◽  
Potato Cyst Nematodes ◽  
Cyst Nematodes ◽  
Viability Assessment ◽  
Reaction Volumes ◽  
Positive Results

Integrated management of potato cyst nematodes (PCN; Globodera rostochiensis and G. pallida) relies heavily on the determination of cyst population densities in soil as well as the viability of the eggs inside the cysts. This study aimed to optimize a quantitative method to determine the number of viable eggs of PCN based on trehalose present in live eggs. Trehalose was extracted from cysts and from a dilution series of eggs and quantified. More trehalose was detected when cysts were crushed than when left intact. Reaction volumes were adapted to the number of eggs because small reaction volumes hampered an accurate extraction of trehalose. A maximum of 10.5 eggs/μl of reaction volume should be used to obtain a significant linear relationship between detected trehalose content and egg numbers. The sensitivity of the trehalose-based method was evaluated by determining the lowest egg detection limit and was defined as five viable eggs. The reliability of this method was tested by comparing efficacy with that of two commonly used assays, visual assessment and hatching test. The trehalose-based method gave viability results similar to those of the visual assessment, which is time consuming, requires trained personnel, and can involve some subjectivity. The hatching test identified fewer viable eggs than the other two methods. In addition, the viability of dead eggs (heated and naturally dead) was tested. No false-positive results (dead eggs declared viable) were obtained with the trehalose-based method. The robustness of the test was demonstrated by measuring the viability of eggs of PCN in different experiments repeated in time. The viability assessment method based on trehalose proved to be an objective as well as sensitive, reliable, robust, fast, and cheap technique for assessing the number of viable eggs in PCN cysts.

Effects of Various Sewage Sludge Treatment Processes on the Survival of Potato Cyst-Nematodes (Globodera spp.) and the Implications for Disposal

1989 ◽  
Vol 21 (8-9) ◽  
pp. 909-916
Author(s):  
A. M. Spaull ◽  
D. M. McCormack ◽  
E. B. Pike
Keyword(s):  
Anaerobic Digestion ◽  
Potato Cyst Nematodes ◽  
Cyst Nematodes ◽  
Sludge Treatment ◽  
Treatment Processes ◽  
Sewage Sludge Treatment ◽  
Thermophilic Digestion ◽  
C 30 ◽  
Effluent Exposure ◽  
Potato Crops

Samples of sewage sludges, taken over a 12-month period from 9 Scottish sewage works, contained on average 0.24 cysts of Globodera spp. (potato cyst-nematodes) of which 11% were viable. The incidence was not significantly related to season or to the presence of vegetable-processing effluent. Exposure of cysts in sludge to mesophilic anaerobic digestion (35 °C, 30 min) cold anaerobic digestion (9 weeks), pasteurisation (70 °C, 30 min) and aerobic thermophilic digestion (60 °C, ld) reduced viability of eggs within the cysts by almost 100%. Sludges so treated can therefore be considered to be free from infection risk to potato crops, although the non-infective cysts may still be recovered. Treatment with lime at pH 11.5 (20 °C, 24 h), by aerobic stabilisation in an oxidation ditch (7 weeks) and by activated-sludge treatment (5d) did not reduced viability acceptably. Accelerated cold digestion did not reduce viability sufficiently after the usual 15 weeks but rendered eggs completely non-viable after 21 weeks. The results show that even sludge treated to destroy viable cysts should not be applied to land used for growing seed potatoes and subject to testing for freedom from infestation. Treatment destroying viability should increase the acceptability of sludge for ware potato growers, although the numbers of cysts applied in untreated sludge would be unlikely to increase significantly levels of cysts in soils already infested.

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.

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