scholarly journals Phytonematodes as a limiting biotic factor of agricultural production in the world (review)

2021 ◽  
Author(s):  
K. A. Kalatur ◽  
L. A. Yanse
Keyword(s):  
Rapid Development ◽  
Molecular Genetic ◽  
Nematode Species ◽  
Bursaphelenchus Xylophilus ◽  
Biotic Factor ◽  
Xiphinema Index ◽  
New Strategy ◽  
Aphelenchoides Besseyi ◽  
Environmentally Safe ◽  
Meloidogyne Spp

Purpose. To analyze domestic and foreign scientific literature on the species composition and harmfulness of the world's most dangerous parasitic species of phytonematodes in crops. Results. Today, according to the available literature, the most dangerous species of phytonematodes include: gall nematode (Meloidogyne spp.), cyst-forming nematode (Heterodera spp. and Globodera spp.), root lesion nematode (Pratylenchus spp.), banana drill nematode (Radoholus similis), stem nematode (Ditylenchus dipsaci), pine stem nematode (Bursaphelenchus xylophilus), reniform nematode (Rotylenchulus reniformis), xiphinema index (Xiphinema index), false head nematode (Nacobbus aberrans), and rice leaf nematode (Aphelenchoides besseyi). Conclusions. The results of research on the prevalence and harmfulness of parasitic nematode species in crops convince us of the need for a more detailed study of this group of microorganisms. Due to the rapid development of molecular genetic methods in the last decade, scientists have been able to expand and improve their knowledge of identifying species, races and pathotypes of phytonematodes, their biological and environmental characteristics, and most importantly, to discover and understand extremely complex mechanisms of parasite and host plants. Nematologists are confident that further research in these and other areas in the future will create a basis for developing a new strategy for long-term and environmentally safe control of these dangerous plant parasites.

scholarly journals Molecular and biochemical characterization of an endo-β-1,3-glucanase from the pinewood nematode Bursaphelenchus xylophilus acquired by horizontal gene transfer from bacteria

2005 ◽  
Vol 389 (1) ◽  
pp. 117-125 ◽  
Author(s):  
Taisei KIKUCHI ◽  
Hajime SHIBUYA ◽  
John T. JONES
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Biochemical Characterization ◽  
Glycosyl Hydrolase ◽  
Functional Characterization ◽  
Nematode Species ◽  
Bursaphelenchus Xylophilus ◽  
Pinewood Nematode ◽  
Sequence Comparisons

We report the cloning and functional characterization of an endo-β-1,3-glucanase from the pinewood nematode Bursaphelenchus xylophilus acquired by horizontal gene transfer from bacteria. This is the first gene of this type from any nematode species. We show that a similar cDNA is also present in another closely related species B. mucronatus, but that similar sequences are not present in any other nematode studied to date. The B. xylophilus gene is expressed solely in the oesophageal gland cells of the nematode and the protein is present in the nematode's secretions. The deduced amino acid sequence of the gene is very similar to glycosyl hydrolase family 16 proteins. The recombinant protein, expressed in Escherichia coli, preferentially hydrolysed the β-1,3-glucan laminarin, and had very low levels of activity on β-1,3-1,4-glucan, lichenan and barley β-glucan. Laminarin was degraded in an endoglucanase mode by the enzyme. The optimal temperature and pH for activity of the recombinant enzyme were 65 °C and pH 4.9. The protein is probably important in allowing the nematodes to feed on fungi. Sequence comparisons suggest that the gene encoding the endo-β-1,3-glucanase was acquired by horizontal gene transfer from bacteria. B. xylophilus therefore contains genes that have been acquired by this process from both bacteria and fungi. These findings support the idea that multiple independent horizontal gene transfer events have helped in shaping the evolution of several different life strategies in nematodes.

scholarly journals A Privacy Protection Model of Data Publication Based on Game Theory

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Li Kuang ◽  
Yujia Zhu ◽  
Shuqi Li ◽  
Xuejin Yan ◽  
Han Yan ◽  
...  
Keyword(s):  
Privacy Protection ◽  
Stackelberg Game ◽  
Rapid Development ◽  
Optimal Number ◽  
Service Development ◽  
Lower Probability ◽  
Data Publication ◽  
Development Organization ◽  
Trade Offs ◽  
New Strategy

With the rapid development of sensor acquisition technology, more and more data are collected, analyzed, and encapsulated into application services. However, most of applications are developed by untrusted third parties. Therefore, it has become an urgent problem to protect users’ privacy in data publication. Since the attacker may identify the user based on the combination of user’s quasi-identifiers and the fewer quasi-identifier fields result in a lower probability of privacy leaks, therefore, in this paper, we aim to investigate an optimal number of quasi-identifier fields under the constraint of trade-offs between service quality and privacy protection. We first propose modelling the service development process as a cooperative game between the data owner and consumers and employing the Stackelberg game model to determine the number of quasi-identifiers that are published to the data development organization. We then propose a way to identify when the new data should be learned, as well, a way to update the parameters involved in the model, so that the new strategy on quasi-identifier fields can be delivered. The experiment first analyses the validity of our proposed model and then compares it with the traditional privacy protection approach, and the experiment shows that the data loss of our model is less than that of the traditional k-anonymity especially when strong privacy protection is applied.

Development of an efficient PCR-based diagnosis protocol for the identification of the pinewood nematode, Bursaphelenchus xylophilus (Nematoda: Aphelenchoididae)

Nematology ◽  
2004 ◽  
Vol 6 (2) ◽  
pp. 279-285 ◽  
Author(s):  
Jae Soon Kang ◽  
Kwang Sik Choi ◽  
Sang Chul Shin ◽  
Il Sung Moon ◽  
Sang Gil Lee ◽  
...  
Keyword(s):  
Intergenic Spacer ◽  
Nematode Species ◽  
Bursaphelenchus Xylophilus ◽  
5S Rrna ◽  
Rrna Gene ◽  
Pinewood Nematode ◽  
Pine Wood ◽  
5S Rrna Gene ◽  
Primer Sets ◽  
Species Specific

Abstract Pine wood wilt disease caused by the pine wood nematode, Bursaphelenchus xylophilus , has been a serious problem in the southern regions of Korea. Efficient diagnosis of B. xylophilus from infected pine wood specimens is critical for the management of this pest. Traditional microscopic examination often results in an erroneous identification because a closely related non-pathogenic species, B. mucronatus, has a great degree of morphological similarity to B. xylophilus. In an attempt to search for reliable molecular markers for the discrimination of these species, we have cloned the 5S rRNA genomic DNA fragments containing both coding and intergenic spacer (IGS) regions from B. xylophilus and B. mucronatus through a homology-probing PCR strategy. Sequence analyses revealed that coding sequences of the 5S rRNA gene from the two species are almost identical (98.3% homology) but that the IGS sequences differ substantially between the species. Based on the IGS sequence differences (69.7% homology), we designed species-specific primer sets and developed a PCR-based diagnosis protocol for the identification and discrimination of the two nematode species on a molecular basis.

scholarly journals New Insights into the Phylogeny and Worldwide Dispersion of Two Closely Related Nematode Species, Bursaphelenchus xylophilus and Bursaphelenchus mucronatus

PLoS ONE ◽  
2013 ◽  
Vol 8 (2) ◽  
pp. e56288 ◽  
Author(s):  
Filipe Pereira ◽  
Cláudia Moreira ◽  
Luís Fonseca ◽  
Barbara van Asch ◽  
Manuel Mota ◽  
...  
Keyword(s):  
Nematode Species ◽  
Bursaphelenchus Xylophilus ◽  
Bursaphelenchus Mucronatus

Boarding abilities of Bursaphelenchus mucronatus and B. xylophilus (Nematoda: Aphelenchoididae) on Monochamus alternatus (Coleoptera: Cerambycidae)

Nematology ◽  
2003 ◽  
Vol 5 (6) ◽  
pp. 843-849 ◽  
Author(s):  
Shota Jikumaru ◽  
Katsumi Togashi
Keyword(s):  
Pine Wilt Disease ◽  
Nematode Species ◽  
Bursaphelenchus Xylophilus ◽  
Insect Vector ◽  
Species Replacement ◽  
Monochamus Alternatus ◽  
Bursaphelenchus Mucronatus ◽  
Initial Load ◽  
Pine Trees ◽  
The Difference

Abstract Bursaphelenchus mucronatus is closely related to Bursaphelenchus xylophilus, the causative agent of pine wilt disease. Both nematodes are transmitted between host pine trees as the fourth-stage dispersal juveniles (JIV) by insect vectors. After the invasion of Japan by B. xylophilus, B. mucronatus, native to Japan, appears to have been replaced in the pine forests during the spread of the disease. To help understand this species replacement, the number of JIV carried by an insect vector (the initial nematode load) was compared between the two nematode species by using the beetle, Monochamus alternatus, in the laboratory. The initial load of B. mucronatus was significantly smaller than that of B. xylophilus although the number of third-stage dispersal juveniles (JIII) concentrated at the pupal chambers did not differ. Statistical analysis showed that the proportion of JIII moulting to JIV was the most important among three components explaining the difference in the initial load of B. mucronatus while the number of JIII concentrated at the pupal chamber was the most important for B. xylophilus. The phoretic affinity between the nematode and its vector is discussed in relation to its role in the species replacement.

Future Potential, Problems, and Practicalities of Herbicide-Tolerant Crops from Genetic Engineering

Weed Science ◽  
1987 ◽  
Vol 35 (S1) ◽  
pp. 28-31 ◽  
Author(s):  
Robert M. Goodman
Keyword(s):  
Genetic Engineering ◽  
Broad Spectrum ◽  
New Technology ◽  
Rapid Development ◽  
Agricultural Practices ◽  
High Potency ◽  
Crop Varieties ◽  
Potential Problems ◽  
Environmentally Safe ◽  
Future Potential

Genetic engineering is a powerful new technology that makes possible rapid development of herbicide tolerances in superior crop varieties. Use of the technology will have a major impact on future agricultural practices and the agrichemical industry. Possible risks as well as significant likely benefits – to agricultural users, corporate suppliers, and the environment – are discussed. Increased product lifetimes, decreased costs, and increased usefulness of broad-spectrum, high-potency, environmentally safe herbicides and herbicide combinations are predicted.

A simple method for discriminating Bursaphelenchus xylophilus and B. mucronatus by species-specific polymerase chain reaction primer pairs

Nematology ◽  
2004 ◽  
Vol 6 (2) ◽  
pp. 273-277 ◽  
Author(s):  
Koji Matsunaga ◽  
Katsumi Togashi
Keyword(s):  
Pcr Amplification ◽  
Nematode Species ◽  
Bursaphelenchus Xylophilus ◽  
Polymerase Chain Reaction Primer ◽  
Dna Fragments ◽  
Simple Method ◽  
Specific Pcr ◽  
Pcr Products ◽  
Specific Pcr Primer ◽  
Species Specific

Abstract Two species-specific PCR primer pairs were developed for identifying the two nematode species, Bursaphelenchus xylophilus and B. mucronatus. The primer pairs were developed from the sequence of ribosomal DNA (rDNA) repeats to produce DNA fragments of different lengths by PCR amplification. The DNA fragments for B. mucronatus and B. xylophilus were 210 bp and 557 bp, respectively. When mixed, neither primer pair inhibited the PCR amplification of the other. Five isolates of B. xylophilus and four isolates of B. mucronatus showed different band profiles of PCR products between the two species, but identical profiles among isolates of the same species.

scholarly journals Differences in Feeding Sites Induced by Root-Knot Nematodes, Meloidogyne spp., in Chickpea

2005 ◽  
Vol 95 (4) ◽  
pp. 368-375 ◽  
Author(s):  
Nicola Vovlas ◽  
Hava F. Rapoport ◽  
Rafael M. Jiménez Díaz ◽  
Pablo Castillo
Keyword(s):  
Giant Cell ◽  
Faba Bean ◽  
Nematode Species ◽  
Giant Cells ◽  
The Other ◽  
Root Knot Nematodes ◽  
Feeding Site ◽  
Feeding Sites ◽  
Meloidogyne Spp ◽  
Meloidogyne Species

Root-knot nematodes (Meloidogyne spp.) are sedentary, obligate endoparasites in plants, where they induce specialized feeding sites. The feeding sites act as strong metabolic sinks to which photosynthates are mobilized. The histopathological modifications in the nematode-induced feeding sites of artificially inoculated chickpea cv. UC 27 were qualitatively and quantitatively compared using five isolates of M. artiellia and one isolate each of M. arenaria, M. incognita, and M. javanica. All Meloidogyne isolates infected chickpea plants, but root gall thickening was significantly less for M. artiellia isolates than for the other Meloidogyne species. Nevertheless, neither the number of giant cells in the feeding site (averaging four to six) nor the area of individual giant cells was influenced by nematode species or isolate. However, the number of nuclei per giant cell was significantly smaller, and the maximum diameters of nuclei and nucleoli were significantly greater, in giant cells induced by M. artiellia isolates than in those induced by M. arenaria, M. incognita, or M. javanica. In a second experiment, M. artiellia-induced giant cells in faba bean and rapeseed also contained a small number of large nuclei.

scholarly journals First Report of the Root Knot Nematode, Meloidogyne inornata, on Common Bean in Paraná State, Brazil

Plant Disease ◽  
2013 ◽  
Vol 97 (3) ◽  
pp. 431-431 ◽  
Author(s):  
A. C. Z. Machado ◽  
O. F. Dorigo ◽  
D. Mattei
Keyword(s):  
Common Bean ◽  
Nematode Species ◽  
State University ◽  
Root Knot Nematode ◽  
First Report ◽  
North Carolina State University ◽  
Adult Females ◽  
Bean Plants ◽  
Meloidogyne Spp ◽  
Species Specific

Common bean (Phaseolus vulgaris F.) is one of the most important crops in Paraná State, which is responsible for almost 10% of the Brazilian production (4). Root knot nematodes, Meloidogyne spp., are common parasites of this crop worldwide, but damage caused by Meloidogyne inornata has not been reported. During a survey of nematode species present on common bean fields in Paraná State, Brazil, galled root samples of cultivars Tuiuiú and Eldorado were submitted, in June 2012, in the Nematology Laboratory from IAPAR, collected in the municipalities of Araucária (25°35′34″S, 49°24′36″W) and Santana do Itararé (23°45′18″S, 49°37′44″W). Plants did not exhibit any above-ground symptoms. The specimens were identified through perineal patterns and esterase phenotypes of 20 adult females extracted from dissected roots (2,3). The population densities observed in the samples were 140 and 700 J2 and eggs per gram of roots, respectively, for both samples. Characteristics were consistent with those described for M. inornata. For example, perineal patterns of M. inornata showed a high dorsal arch, with smooth to wavy striae, similar to those of M. incognita; but no punctate markings between anus and tail terminus were observed. However, from the esterase electrophoresis we obtained the I3 (Rm = 0.83, 1.15, and 1.32) phenotype, typical of M. inornata, a species-specific phenotype used to differentiate this species from M. incognita (1). Moreover, the excretory pore of adult females was located 32.1 (± 5.4) μm from the anterior end, consistent with the M. inornata description (25 to 53 μm) (1). To the best of our knowledge, this is the first report of M. inornata parasitizing common bean roots. This finding has great importance for Brazilian agriculture, since this nematode may damage common bean plants and become an additional problem for this crop. Additional work is necessary in order to elucidate the losses caused by M. inornata on common bean. References: (1) R. M. D. G. Carneiro et al. Nematology 10:123, 2008. (2) P. R. Esbenshade and A. C. Triantaphyllou J. Nematol. 22:10, 1990. (3) K. M. Hartman and J. N. Sasser. Page 115 in: An Advanced Treatise on Meloidogyne, Volume II Methodology. K. R. Barker et al., eds. Raleigh: North Carolina State University Graphics, 1985. (4) MAPA. Feijão, Ministério da Agricultura, Brasil. Retrieved from http://www.agricultura.gov.br/vegetal/culturas/feijao September 05, 2012.

scholarly journals Molecular Characterization of Meloidogyne hispanica (Nematoda, Meloidogynidae) by Phylogenetic Analysis of Genes Within the rDNA in Meloidogyne spp.

Plant Disease ◽  
2008 ◽  
Vol 92 (7) ◽  
pp. 1104-1110 ◽  
Author(s):  
Blanca B. Landa ◽  
Juan E. Palomares Rius ◽  
Nicola Vovlas ◽  
Regina M. D. G. Carneiro ◽  
Carla M. N. Maleita ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Nematode Species ◽  
Maximum Parsimony Analysis ◽  
Biological Traits ◽  
Root Knot Nematode ◽  
Specific Pcr ◽  
Meloidogyne Spp ◽  
Species Specific ◽  
Prunus Spp

In the past, the distribution of Meloidogyne hispanica, the Seville root-knot nematode, appeared to be restricted to the southern part of Spain and Prunus spp.; however, its distribution has been confirmed to be worldwide because it occurs in all continents (Europe, Africa, Asia, Australia, and North, Central, and South America). Differentiation of M. hispanica from other Meloidogyne spp., mainly M. arenaria, can be very difficult using morphological and biological traits data. These species are quite similar and can be regularly confused in inaccurate taxonomic comparisons. In this study, species-specific polymerase chain reaction (PCR) and phylogenetic analysis of sequences from three ribosomal (r)DNA regions (18S, internal transcribed spacer [ITS]1-5.8S-ITS2, and D2-D3 of 28S) were used to characterize three M. hispanica isolates from different geographical origins (Brazil, Portugal, and Spain). Molecular analyses showed identical sequences for all three isolates for the three rDNA regions. Maximum parsimony analysis of the three rDNA regions and the species-specific PCR demonstrated and supported the differentiation of M. hispanica from M. incognita, M. javanica, and M. arenaria and from all described root-knot nematode species.

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