Showing papers on "Globodera rostochiensis published in 2015"
TL;DR: A novel role for an apoplastic expansin-like protein in suppressing intra-cellular defense responses is shown, consistent with the scenario whereby potato cyst nematodes secrete effectors that modulate host cell fate and metabolism as well as modifying host cell walls.
Abstract: The potato cyst nematode, Globodera rostochiensis, is an important pest of potato. Like other pathogens, plant parasitic nematodes are presumed to employ effector proteins, secreted into the apoplast as well as the host cytoplasm, to alter plant cellular functions and successfully infect their hosts. We have generated a library of ORFs encoding putative G. rostochiensis putative apoplastic effectors in vectors for expression in planta. These clones were assessed for morphological and developmental effects on plants as well as their ability to induce or suppress plant defenses. Several CLAVATA3/ESR-like proteins induced developmental phenotypes, whereas predicted cell wall-modifying proteins induced necrosis and chlorosis, consistent with roles in cell fate alteration and tissue invasion, respectively. When directed to the apoplast with a signal peptide, two effectors, an ubiquitin extension protein (GrUBCEP12) and an expansin-like protein (GrEXPB2), suppressed defense responses including NB-LRR signaling induced in the cytoplasm. GrEXPB2 also elicited defense response in species- and sequence-specific manner. Our results are consistent with the scenario whereby potato cyst nematodes secrete effectors that modulate host cell fate and metabolism as well as modifying host cell walls. Furthermore, we show a novel role for an apoplastic expansin-like protein in suppressing intra-cellular defense responses.
51 citations
TL;DR: All SPRYSEC proteins tested are able to suppress defense responses induced by NB-LRR proteins as well as cell death induced by elicitors, suggesting that defense repression is a common characteristic of members of this effector protein family.
Abstract: Potato cyst nematodes (PCNs), including Globodera rostochiensis (Woll.), are important pests of potato. Plant parasitic nematodes produce multiple effector proteins, secreted from their stylets, to successfully infect their hosts. These include proteins delivered to the apoplast and to the host cytoplasm. A number of effectors from G. rostochiensis predicted to be delivered to the host cytoplasm have been identified, including several belonging to the secreted SPRY domain (SPRYSEC) family. SPRYSEC proteins are unique to members of the genus Globodera and have been implicated in both the induction and the repression of host defense responses. We have tested the properties of six different G. rostochiensis SPRYSEC proteins by expressing them in Nicotiana benthamiana and N. tabacum. We have found that all SPRYSEC proteins tested are able to suppress defense responses induced by NB-LRR proteins as well as cell death induced by elicitors, suggesting that defense repression is a common characteristic of members of this effector protein family. At the same time, GrSPRYSEC-15 elicited a defense responses in N. tabacum, which was found to be resistant to a virus expressing GrSPRYSEC-15. These results suggest that SPRYSEC proteins may possess characteristics that allow them to be recognized by the plant immune system.
33 citations
TL;DR: Soil amendments with aqueous solutions of vermicompost alone or in combination with urea were more effective than the solid verMicompost used alone, for controlling both species, and had positive effects on plant fresh stem weight and stem height.
Abstract: The addition of organic material to the soil can be an effective alternative to the environmentally unsafe chemical treatments that are used to control plant parasitic nematodes. We evaluated the effects of vermicompost alone, and aqueous solutions of vermicompost (vermicompost tea) either alone or mixed with urea, on the development and survival of two potato-cyst nematodes: Globodera rostochiensis (pathotype Ro1) and G. pallida (pathotype Pa2) and on the growth parameters of the host potato plants. Soil amendments with these materials significantly decreased the number of cysts · 400 g–1 of both species in the soil, the number of eggs and juveniles · cyst–1 of both species, and the number of eggs and juveniles · g–1 of both species in the soil, relative to the untreated controls. The suppressive effect was significantly higher at the highest dose than the lowest treatment dose, for all tested materials. Globodera rostochiensis was more sensitive to all the tested materials than G. pallida. The aqueous solutions of vermicompost alone or in combination with urea were more effective than the solid vermicompost used alone, for controlling both species. Vermicompost and the vermicompost teas had positive effects on plant fresh stem weight and stem height. The application of vermicompost tea instead of the solid vermicompost, substantially decreased the amount of material needed. These amendments are thus promising for the control of potato-cyst nematodes in sustainable agricultural systems.
28 citations
TL;DR: Potato ( Solanum tuberosum ) is the second most important food crop in Kenya after maize (MOA, 2007), however, increased production in Kenya has been constrained by various factors including pests and diseases.
Abstract: Potato ( Solanum tuberosum ) is the second most important food crop in Kenya after maize (MOA, 2007) However, increased production in Kenya has been constrained by various factors including pests and diseases Potato cyst nematode (PCN) is…
28 citations
TL;DR: The results herein presented indicate presence of virus and nematode resistance genes in accessions of the Chilota Potato Genebank, and 99 accessions out of the 271 tested possess the Ryadg resistance gene and 17 accessions have the Rysto resistance gene.
Abstract: Potato Genebank of the Universidad Austral de Chile (UACh) is an important gene bank in Chile. The accessions collected all over the country possess high genetic diversity, present interesting agronomic and cooking traits, and show resistance to biotic and abiotic stress. A particularly interesting subgroup of the gene bank includes the accessions collected in the South of Chile, the Chilota Potato Genebank. The focus of this study is the identification of virus and nematode resistant genes in potatoes (Solatium tuberosum L.), using the RYSC3 and YES3-3B molecular markers. The Potato virus Y(PVY) resistance genes Ryadg and Rysto were identified. Furthermore, the CP60 marker was used to assess the Rx resistance gene that confers resistance to Potato virus X (PVX). In addition, the HC and GRO1-4 markers were utilized to identify the GpaVvrn_QTL and Gro1-4, resistance genes of Globodera pallida and Globodera rostochiensis, respectively. Both G. pallida and G. rostochiensis are Potato Cyst Nematodes (PCN). The plant material used in this study included leaves from 271 accessions of the gene bank. These samples were collected in the field where natural pathogen pressure of potential viruses and diseases exists. ELISA assays were run for field detection of PVY and PVX. However, there have been no previous reports of nematode presence in the plant material. The results herein presented indicate presence of virus and nematode resistance genes in accessions of the Chilota Potato Genebank. In terms of virus resistance, 99 accessions out of the 271 tested possess the Ryadg resistance gene and 17 accessions of these 271 tested have the Rysto resistance gene. Also, 10 accessions showed positive amplification of the Rxl resistant gene marker. As to nematode resistance, 99 accessions have possible resistance to G. pallida and 54 accessions show potential resistance to G. rostochiensis as detected using the available molecular markers.
14 citations
Journal Article•
TL;DR: The life cycle of G. rostochiensis under the climatic conditions of southwestern Quebec was reported, with a minimum of 579 growing degree units (GDU) to complete its life cycle and the first mature cysts were observed 42 to 63 days after planting.
Abstract: In 2006, the golden cyst nematode, Globodera rostochiensis, was discovered in the province of Quebec, Canada. We report here the life cycle of G. rostochiensis under the climatic conditions of southwestern Quebec. Only one full generation was completed per year under these latitudes. On susceptible potato cv. Snowden, G. rostochiensis needed a minimum of 579 growing degree units (GDU) (base 5.9°C) to complete its life cycle and the first mature cysts were observed 42 to 63 days after planting (DAP). In soil, second-stage juveniles (J2) were first observed 14 to 21 DAP, whereas both white females on roots and males in soil appeared synchronously after 35 to 42 days. The duration of the life cycle was affected by temperature but not by soil type. A second wave of hatching systematically occurred later in the season and a second generation of males was observed during the 2011 growth season. No complete second cycle was observed before plant senescence. Climate change and later maturing cultivars/crops could allow the development of a full second generation in the future.
9 citations
TL;DR: 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.
Abstract: 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 tha...
8 citations
TL;DR: The response to α-solanine of nematodes pre-exposed to a 3 mM ZnSO 4 solution was significantly suppressed compared to that of water control and is the first evidence that both α- solanine and Znso 4 can affect the behaviour of hatched J2 of PCN.
Abstract: 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 ZnSO 4 (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 ZnSO 4 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 ZnSO 4 can affect the behaviour of hatched J2 of PCN.
7 citations
01 Jan 2015
TL;DR: The linear regression with lg(X+I) transformation has been used to model the Pi and Pf effect on both, potato height and yield and suggested an interspecies competition.
Abstract: MANEVA, S. and Zl. TRIFONOVA, 2015. Globodera rostochiensis population density effect on potato growth and yield. Regression models estimation. Bulg. J. Agric. Sci., 21: 815–821 Effect of initial population densities (Pi) of Bulgarian population of Globodera rostochiensis on the population dynamics and potato plants growth and yield was investigated in glasshouse and estimated using mathematical models. Potato cv. Nadejda seedlings were inoculated with Pi levels of 0, 0.1, 0.2, 0.5, 1, 2, 4, 8, 16, 32, 64 or 128 second stage juveniles/cm 3 soil. The relation between Pi and final population density (Pf) was linear and DWLS regression described the relation of nematode reproductive index (Ri) and Pi. The linear regression with lg(X+I) transformation has been used to model the Pi and Pf effect on both, potato height and yield. Tolerance limit of potato to G. rostochiensis was between 0.5 and 1 juveniles/cm 3 soil. The reduction of yield was significant different at 1.0 Pi. The model predicted that 4.0 Pi caused 50% yield loss and the maximal yield suppression of 87.6% occurred at 128 Pi. Maximum Ri of 27.0 occurred at 4.0 Pi, suggesting an interspecies competition.
3 citations
19 May 2015
TL;DR: It took 8 the authors weeks of inundation of non-amended soil to reduce nematode survival by 72 %, while in amended soils survival was reduced up to 99.9 % after 4 weeks, and higher concentrations of SCFA and carbon dioxide and lower levels of oxygen were detected in amended treatments.
2 citations
TL;DR: The results suggest the potential exploitation of the cultivar Venezolana Negra in breeding programmes in order to improve pest and disease resistance of potato.
Abstract: In the Canary Islands, a number of old Andean potato introductions have been maintained by farmers and are cultivated there since the sixteenth century Genetic resistance is an inexpensive way to control the main pests and diseases of potato and avoids the use of phytochemicals or other costly protective measures In this study, we have analysed eight Solanum tuberosum subsp andigena and S tuberosum subsp tuberosum accessions, representing old potato varieties from Tenerife Island, for their resistance levels to Phytophthora infestans, Globodera rostochiensis, Globodera pallida and Pectobacterium atrosepticum New resistance sources against P infestans in leaves and P atrosepticum were found, as well as partial resistance to both nematode species The results suggest the potential exploitation of the cultivar Venezolana Negra in breeding programmes in order to improve pest and disease resistance of potato
20 Dec 2015
TL;DR: A distinct DNA marker for Hero A was developed and these new distinct polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) markers were evaluated to evaluate the Detection of the potato cyst nematode resistance gene Hero A in Japanese tomato cultivars by the PCR- RFLP method.
Abstract: Potato cyst nematodes (PCNs) Globodera rostochiensis (Woll.) and G. pallida Stone are major pests of potato growing areas worldwide (Brodie et al., 1998). PCNs are classified into pathotypes on the basis of their ability to multiply on different potato clones. Kort et al. (1977) proposed the International Scheme for Globodera pathotypes in which, among the European populations, five pathotypes within G. rostochiensis and three pathotypes within G. pallida were recognized. In Japan, G. rostochiensis was first found in 1972 within a potato field in Makkari Village, Hokkaido (Yamada et al., 1972). It subsequently spread to other parts of Hokkaido and other districts in Japan. Globodera rostochiensis pathotype Ro1 is the only species and pathotype present in Japan (Kushida and Momota 2005). PCN can also reproduce on tomato and has been reported as a problem for tomato growing regions in Europe (Ellis, 1968; Ellis and Maxon Smith, 1971; Graham, 1966; Hesling and Ellis, 1972; Trifonova et al., 1995). In Hokkaido, it was also reported that PCN was detected in tomato plants (Hokkaido Plant Protection Office, 1997). In good agricultural practice, nematodes are controlled by crop rotation and the use of nematocides and resistant cultivars. The exploitation of host resistance is the most effective and environmentally benign method for managing plant nematodes. Several PCN resistance genes have been characterized genetically within Solanum species and have been exploited successfully in potato breeding (Ross, 1986). For example, the dominant nematode resistance gene H1 from S. tuberosum ssp. andigena (Ellenby, 1954) has been used extensively to provide a high level of durable resistance against G. rostochiensis pathotypes Ro1 and Ro4 within potato cultivars worldwide (Brodie et al., 1998; Ross, 1986). Recently, we found a number of Japanese tomato cultivars with resistance to G. rostochiensis (Uehara et al., 2008). A PCN resistance gene, Hero, was identified in a wild tomato variety, and this gene was introgressed into the tomato breeding line LA1792 (Ellis and MaxonSmith, 1971). Cabrera Poch et al. (2006) reported that the HERO_F2/HERO_R3 primer pair could be used to amplify two closely sized DNA fragments from tomato breeding line LA1792 (resistant) and one fragment from the cultivar Moneymaker (susceptible). Using the HERO_F2/HERO_R3 primer pair, we also confirmed that the tested resistant tomato cultivars in Japan contained the Hero A gene, whereas susceptible cultivars did not (Uehara et al., 2010). When this primer pair was used, however, the two DNA fragments from resistant cultivars were located very close to each other after electrophoresis. Therefore, we tried to develop a distinct DNA marker for Hero A. We then used these new distinct polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) markers to evaluate our Detection of the potato cyst nematode resistance gene Hero A in Japanese tomato cultivars by the PCR-RFLP method
01 Jan 2015
TL;DR: The article presents the results of studying VIR’s potato collection, and the cultivars combining resistance to gold potato cyst nematode with other valuable commercial traits are described.
Abstract: The article presents the results of studying VIR’s potato collection. Following such study, the best cultivars of potato are recommended as source material for breeding programs targeted at basic commercial traits, such as high yield, starch content, resistance to late blight ( Phytophthora infestans (Mont.) de Bary) and Ro1 pathotype of golden potato cyst nematode ( Globodera rostochiensis (Woll.) Behr.). Described here are the cultivars combining resistance to gold potato cyst nematode with other valuable commercial traits. The identified genotypes are recommended to be included in potato breeding programs.
01 Jan 2015
TL;DR: The potato crop in the surveyed area had patches of poor growth with potatoes showing severe stunting, yellowing, wilting and reduced size of the tubers, close examination of the root system showed tiny white, yellow or brownish pinhead size cysts.
Abstract: Surveys targeting the potato crop were conducted during 2014 when soil samples were collected from five potato-growing areas of Nyandarua County leading to the recovery of what appeared to be PCN cysts from cv. Cangi and other unidentified farmer varieties. The potato crop in the surveyed area had patches of poor growth with potatoes showing severe stunting, yellowing, wilting and reduced size of the tubers. Close examination of the root system showed tiny white, yellow or brownish pinhead size cysts. The cysts and second stage juveniles (J2) were extracted from the soil samples and their morphological characteristics examined
Journal Article•
TL;DR: Evaluating the efficacy of bio-fumigation by incorporating chopped residues of radish, cabbage and cauliflower in potato cv.
Abstract: Potato cyst nematodes (PCN) Globodera rostochiensis (Woll) and G. pallida (Stone) hinder the sustainable production of potato in the Nilgiri hills of Tamil Nadu. It remains as a serious endemic pest of potato in this region due to intensive cultivation of potato and favourable climatic conditions. Hence, field experiments were conducted to evaluate the efficacy of bio-fumigation by incorporating chopped residues of radish, cabbage and cauliflower in potato cv. Kufri Giriraj. One set of treatments were covered with transparent polyethylene sheets for 4 weeks before planting and another set was left uncovered. The biofumigants were compared with the chemical nematicide carbofuran @ 2 kg a.i /ha. The treatments were replicated thrice in a randomized block design. The results revealed that all the treatments significantly increased the potato yield and decreased the nematode population. Incorporation of radish leaves @ 1 kg/m 2 and covering with polyethylene sheet recorded maximum growth parameters, yield (25.97 t/ha) and minimum PCN reproduction factor (Rf) 1.21. It was on par with carbofuran treatment which yielded 25.09 t/ha and PCN reproduction factor (Rf) 1.24 and was followed by cabbage and cauliflower residues covered with polyethylene sheet.
TL;DR: The transcriptional activity of R genes was detected not only in roots but also in leaves in the case of both genetic and induced resistance, indicating the development of a systemic defense response of plants to infection.
Abstract: The characteristics of expression of two genes, H1 and Gro1-4, which determine the resistance to the sedentary parasitic nematode Globodera rostochiensis (Wollenweber, 1923) Behrens, 1975, in the resistant (Krepysh) and susceptible (Nevskii) potato cultivars was studied under a short-term exposure to low temperatures. Such treatment of susceptible plants at the early stages of ontogeny led to the activation of expression of H1 and Gro1-4 genes in roots and the H1 gene in leaves. The transcriptional activity of R genes was detected not only in roots but also in leaves (i.e., in tissue remote from the site of direct injury by the nematode) in the case of both genetic and induced resistance, indicating the development of a systemic defense response of plants to infection.
01 Jan 2015
TL;DR: Soil amendments with vermicompost alone or in combination with urea were more effective than the solid vermicomost used alone, for controlling both species, and had positive effects on plant fresh stem weight and stem height.
Abstract: The addition of organic material to the soil can be an effective alternative to the environmentally unsafe chemical treat- ments that are used to control plant parasitic nematodes. We evaluated the effects of vermicompost alone, and aqueous solutions of vermicompost (vermicompost tea) either alone or mixed with urea, on the development and survival of two potato-cyst nematodes: Globodera rostochiensis (pathotype Ro1) and G. pallida (pathotype Pa2) and on the growth parameters of the host potato plants. Soil amendments with these materials significantly decreased the number of cysts · 400 g-1 of both species in the soil, the number of eggs and juveniles · cyst-1 of both species, and the number of eggs and juveniles · g-1 of both species in the soil, relative to the untreated controls. The suppressive effect was significantly higher at the highest dose than the lowest treatment dose, for all tested materials. Globodera rostochiensis was more sensitive to all the tested materials than G. pallida. The aqueous solutions of vermicompost alone or in combination with urea were more effective than the solid vermicompost used alone, for controlling both species. Vermicompost and the vermicompost teas had positive effects on plant fresh stem weight and stem height. The application of vermicompost tea instead of the solid vermicompost, substantially decreased the amount of material needed. These amendments are thus promising for the control of potato-cyst nematodes in sustainable agricultural systems.
TL;DR: In this paper, the results of identification of potato cyst Nematodes (Globodera rostochiensis and G. pallida) were verified using molecular methods.
Abstract: Summary Laboratories of the State Plant Health and Seed Inspection Service to assess the occurrence of the Potato Cyst Nematodes (Globodera rostochiensis and G. pallida) over the period 2009–2013, analysed 213,161 soil samples taken from fields on Polish territory. Viable cysts (ie. containing living eggs and juveniles) from Globodera genus were extracted from 951 soil samples (0.45%). The results of identification of cysts detected in 584 samples (61.41%) were verified using molecular methods. These cysts were preliminary identified to species G. rostochiensis – 547 samples, G. artemisiae – 35 samples and a mixture of two species G. rostochiensis and G. pallida in 1 sample, based on morphometric characters. The result of identification of cysts in one sample was vague. Molecular tests confirmed the results of identification based on morphometric characters. Similarly one of the tested cyst samples where identification results were unclear was finally identified by molecular tests to G. pallida. In addition, cysts detected in the soil attached to two samples of table potatoes originating from Cyprus, were identified to G. rostochiensis and G. pallida species by morphometric characters and with molecular tests.