Kazuyoshi Futai - Profile on Academia.edu (original) (raw)
Papers by Kazuyoshi Futai
Fundamental and applied nematology, 1997
Acceptecl for publication 9July 1997. Summary -The Japanese pine sawyer, /VIonochamus ailernalUs,... more Acceptecl for publication 9July 1997. Summary -The Japanese pine sawyer, /VIonochamus ailernalUs, that emerged From blocks inoculated first with OphiosLOma minus then with Trichoderma sp. (O+T) carried more pinewood nematodes (PWN, Bursaphe/enchus xy/ophi/us) than those emerging From blocks inoculated with these two fungi simultaneously (O,T togeù1er) or inoculated first with Trichoderma (T+O). This was because: z) PWN populations were much larger in the O+T blocks than in the blocks with the other treatments, and ii) the percentage of third-stage dispersal juveniles, dauer juveniles, and PWN which actually transferred to the beetle were much higher in the O+T blocks. By contras t, the numbers of PWN carried by the beetles emerging From blocks inoculated with both 0. minus and Vérticil/ium sp. were much smaller regardless of the inoculation sequence because PWN populations did not build up. We conclude that the species of fungi which are most prevalent in pi ne wilt-killed trees will help determine the number of P\X!N carried by the beetles emerging from the wood. Résumé -Effets des interactions fongiques sur le nombre de Bursaphelenchus xylophilus (Ne1natoda: Aphelenchoididae) transportés par Monochamus alternatus (Coleoptera: Cerambycidae) -Monochamus a/lernaLUS sortant de blocs de bois préalablement inoculés avec OphiosLOma minus et ensuite avec Trichoderma sp. (0+T) transporte un plus grand nombre de Bursaphelenchus xy/ophilus (PWN) que ceux sortant de blocs inoculés simultanément avec ces deux champignons (0, T) ou inoculés avec Trichoderma sp. puis avec 0. minus (T +0). La raison en est que: 1) les populations de PWN sont plus élevées dans les blocs 0+ T que dans ceux des autres traitements, et que il) le pourcentage de juvéniles de dispersion de 3 e stade, les "dauer" juvéniles et les PWN qui passent réellement dans l'insecte sont plus nombreux dans les blocs O+T. En contraste, le nombre de PWN transportés par l'insecte sortant de blocs inoculés avec 0. minus et Umici/lium sp. est beaucoup moins élevé quelle que soit la séquence d'inoculum parce que les populations de PWN ne s'y établissent pas. Il est conclu que les espéces de champignons les plus abondantes dans les pins tués par le desséchement concourent à déterminer le nombre de PWN transportés par l'insecte sortant du bois.
PLOS ONE, Jun 21, 2013
Since it was first introduced into Asia from North America in the early 20 th century, the pine w... more Since it was first introduced into Asia from North America in the early 20 th century, the pine wood nematode Bursaphelenchus xylophilus has caused the devastating forest disease called pine wilt. The emerging pathogen spread to parts of Europe and has since been found as the causal agent of pine wilt disease in Portugal and Spain. In 2011, the entire genome sequence of B. xylophilus was determined, and it allowed us to perform a more detailed analysis of B. xylophilus parasitism. Here, we identified 1,515 proteins secreted by B. xylophilus using a highly sensitive proteomics method combined with the available genomic sequence. The catalogue of secreted proteins contained proteins involved in nutrient uptake, migration, and evasion from host defenses. A comparative functional analysis of the secretome profiles among parasitic nematodes revealed a marked expansion of secreted peptidases and peptidase inhibitors in B. xylophilus via gene duplication and horizontal gene transfer from fungi and bacteria. Furthermore, we showed that B. xylophilus secreted the potential host mimicry proteins that closely resemble the host pine's proteins. These proteins could have been acquired by host-parasite co-evolution and might mimic the host defense systems in susceptible pine trees during infection. This study contributes to an understanding of their unique parasitism and its tangled roots, and provides new perspectives on the evolution of plant parasitism among nematodes.
The infestation pattern of Platypus quercivorus on Fagus crenata
The Japanese Forest Society Congress, 2007
Making headway in understanding pine wilt disease: What do we perceive in the postgenomic era?
Journal of Bioscience and Bioengineering, Jul 1, 2013
The advent of next generation sequencing has revolutionized research approaches to biology by mak... more The advent of next generation sequencing has revolutionized research approaches to biology by making entire genome sequences available and marking a new age in biology that has the potential to open innovative research avenues in various fields. Genome sequencing is now being applied in the fields of forest ecology and forest pathology, which previously had limited access to molecular techniques. One of the most advanced areas of progress is the study of "pine wilt disease", which is caused by the parasitic nematode, Bursaphelenchus xylophilus. The entire genome sequence of B. xylophilus was determined in 2011, and since then, proteomic studies have been conducted to understand the molecular basis of the parasitism and pathogenicity of B. xylophilus. These postgenomic studies have provided numerous molecular insights and greatly changed our understanding of the pathogenesis of pine wilt disease. Here, we review the recent advances in genomic and proteomic approaches that address some of the longstanding questions behind the pathogenesis of pine wilt disease and have identified future questions and directions in this regard.
Regression analysis for the estimation of a sound seed ratio in Pinus thunbergii
Journal of The Japanese Forest Society, May 1, 1991
Biocontrol of Meloidogyne incognita on tomato using antagonistic fungi, plant-growth-promoting rhizobacteria and cattle manure
Pest Management Science, May 8, 2009
BACKGROUND: Biocontrol achieved by a single biocontrol agent is generally inconsistent under fiel... more BACKGROUND: Biocontrol achieved by a single biocontrol agent is generally inconsistent under field conditions. The aim of the present study was to increase the competitiveness and efficacy of biocontrol agents by using them together with cattle manure.RESULTS: The effects of antagonistic fungi [Aspergillus niger v. Teigh., Paecilomyces lilacinus (Thom) Samson and Penicillium chrysogenum Thom] and plant‐growth‐promoting rhizobacteria (PGPR) [Azotobacter chroococcum Beijer., Bacillus subtilis (Ehrenberg) Cohn and Pseudomonas putida (Trev.) Mig.] were assessed with cattle manure on the growth of tomato and on the reproduction of Meloidogyne incognita (Kof. & White) Chitwood. Application of antagonistic fungi and PGPR alone and in combination with cattle manure resulted in a significant increase in the growth of nematode‐inoculated plants. The highest increase (79%) in the growth of nematode‐inoculated plants was observed when P. putida was used with cattle manure, followed by use of P. lilacinus plus cattle manure. Paecilomyces lilacinus resulted in a high reduction in galling and nematode multiplication, followed by P. putida, B. subtilis, A. niger, A. chroococcum and P. chrysogenum. The combined use of P. lilacinus with cattle manure resulted in a maximum reduction in galling and nematode multiplication.CONCLUSION: Application of P. lilacinus or P. putida with cattle manure was useful to achieve greater biocontrol of M. incognita on tomato. Copyright © 2009 Society of Chemical Industry
Bursaphelenchus xylophilus and B. mucronatus in Japan: where are they from?
BRILL eBooks, 2004
ABSTRACT
Phylogenetic relationship among several isolates of Bursaphelenchus xylophilus and B. mucronatus based on their ribosomal DNA sequences
Nematology, 2007
The relationship between the pine wood nematode (PWN), Bursaphelenchus xylophilus, and fungi coha... more The relationship between the pine wood nematode (PWN), Bursaphelenchus xylophilus, and fungi cohabiting in 15-yearold Japanese black pine, Pinus thunbergii, was examined at intervals of 2 months over a year following inoculation with PWN. The population of PWN in the trees was large in August, but decreased slightly in December then increased again in February. Eighteen species of fungi were isolated from wood samples of the pine trees examined. Among them were Phialophora repens, Sphaeropsis sapinea, Pestalotiopsis spp. and Rhizoctonia sp., which were detected most frequently every season. All of these dominant fungi had positive effects on increasing the nematode population except for Rhizoctonia sp., on which PWN propagated less. Under laboratory conditions, 18 species of fungi isolated from pine trees and Botrytis cinerea cultured on potato dextrose agar served as food for PWN, and PWN population build up was compared at 20 • C. PWN increased significantly on Pestalotiopsis sp. 1, Pestalotiopsis sp. 2, Sphaeropsis sapinea, Phialophora repens and B. cinerea from 10-15 days after inoculation. From the viewpoint of food quality and their cohabiting ability, we concluded that the species of fungi that were dominant in the pine trees, except for Rhizoctonia sp., had a compatible relationship with PWN, whilst Rhizoctonia sp. and Penicillium spp. were neutral, and Trichoderma spp. had an incompatible relationship with PWN.
A simple, polymerase chain reaction-restriction fragment length polymorphism-aided diagnosis method for pine wilt disease
Forest Pathology, Jun 1, 2000
SummaryFor diagnosis of pine wilt disease, a simple PCR‐RFLP method was developed to identify and... more SummaryFor diagnosis of pine wilt disease, a simple PCR‐RFLP method was developed to identify and to differentiate two similar nematode species, based on a living or preserved single specimen. Pinewood nematodes, Bursaphelenchus xylophilus, and Bursaphelenchus mucronatus were examined. A single nematode in 1 µl of distilled water was put on a glass slide. When the water had almost dried the nematode was crushed with a filter paper chip, 1.5 mm × 1.5 mm, with the aid of forceps. The filter paper chip containing nematode remains was immediately placed into PCR buffer as the DNA template. The primer set used was to amplify ribosomal DNA containing the inter‐transcribed spacer (ITS) 1, 5.8S and ITS2 regions. The PCR product was consistently obtained from a single nematode, and digesting the product with restriction endonuclease, Hinf I, enabled discrimination between B. xylophilus and B. mucronatus. This method was simple, convenient and definitive, and could successfully determine the pathogen in the diagnosis of pine wilt disease. This method was applicable also to nematode specimens preserved under various conditions except in the case of those preserved in aldehyde‐containing fixatives.
The Relationship Between the Pinewood Nematode (PWN) and Fungi Cohabiting in aine Trees Inoculated with the PWN
Springer eBooks, Aug 27, 2008
... Although the dominant fungi were constantly detected over the experimental period, the compos... more ... Although the dominant fungi were constantly detected over the experimental period, the composi-tion of fungal species slightly varied among seasons as reported in previous studies (Kobayashi et al., 1974, 1975; Fukushige and Futai, 1987; Kuroda and Ito, 1992). ...
A comprehensive understanding of pine wilt disease
Journal of Nanjing Forestry University, 2010
Mortality of Quercus laurifolia trees that had been planted in Japan occurred in. This was caused... more Mortality of Quercus laurifolia trees that had been planted in Japan occurred in. This was caused by an attack by the ambrosia beetle Platypus quercivorus, which causes a disease called Japanese oak wilt and results in mass mortality of Fagaceae trees in Japan. In order to study the infestation of Q. laurifolia by P. quercivorus, dead trees were cut into bolts, and the density of holes bored by P. quercivorus was examined for each bolt. Tube traps were attached to each hole in the bolts of the cut trees, and the number of offspring that emerged from the hole during (the year following the infestation) was counted. Similar to other Japanese Fagaceae species, the density of holes bored by P. quercivorus decreased with increase in the height of Q. laurifolia. The sex ratio of the emerged beetle was biased towards males, and the number of offspring per hole ranged from to. The effects of the height and the hole density on the number of offspring were analyzed with zero-altered negative binomial models with a hurdle component and a truncated count component. The results of the hurdle component in the model for zero counts showed that the probability that one or more beetles emerged from holes was negatively affected by the height above the ground. According to the results of the count component of the model for positive counts, the number of offspring showed a unimodal distribution, with a peak at around one in the density of holes per cm. Japanese oak wilt, laurel oak, reproductive success rate, zero-altered negative binomial model Quercus laurifolia Platypus quercivorus zero-altered negative binomial model cm zero-altered negative binomial model
Agrivita : Journal of Agricultural Science, Oct 1, 2012
Beetle activity deep inside wood was studied in field (Mt. Yoshida, Kyoto) and laboratory conditi... more Beetle activity deep inside wood was studied in field (Mt. Yoshida, Kyoto) and laboratory conditions by monitoring the type and amount of frass ejected from beetle galleries of Platypus quercivorus. Twenty-one galleries were selected from five infested Quercus serrata trees for field studies. In the laboratory, frass production was monitored for three galleries using a computer-aided electrical balance (A&D Co. Ltd.). Long-term patterns of frass production from field observation revealed that there are three distinguishable stages; a fibrous frass stage, an intermediate stage, and a powdery frass stage. The duration of the fibrous frass production was clearly different between galleries, ranging from five to twenty one days. The intermediate stage was also different from gallery to gallery, ranging from two to twenty days. Accordingly, the starting time of the third stage, powdery frass production, ranged from the 19 th to the 27 th day. Under laboratory conditions, the longterm patterns of frass production revealed that in galleries of logs no. 1 and 2 the fibrous frass period was stopped on the 23 rd and 22 nd day, respectively. Field monitoring revealed there was a negative relationship between the length of fibrous frass stage and the length of the intermediate stage.
Pine wood nematode, Bursaphelenchus xylophilus, exhibits a wide range of intraspecific variation ... more Pine wood nematode, Bursaphelenchus xylophilus, exhibits a wide range of intraspecific variation in several biological traits. Among them virulence (degree of pathogenicity), reproductive ability and boarding ability on the vector beetle are important pathogenicityrelated traits, although their molecular basis has not been determined. In this study we generated a set of recombinant inbred lines (RILs) of B. xylophilus from two inbred lines, F7 and P9, which greatly differ in the degree of pathogenicity. In addition, we conducted bioassays to estimate above-mentioned three traits in the newly obtained 17 RILs and two parental inbred lines. As a result, RILs showed various virulences and reproductions along a continuum and two distinct transmission abilities. This indicates that virulence and reproduction may be quantitative, polygenic trait, while transmission ability is a qualitative trait which is controlled by a single or few genes.
In recent years a hypothesis was proposed that not pine wood nematode, but its accompanying bacte... more In recent years a hypothesis was proposed that not pine wood nematode, but its accompanying bacteria is responsible for the symptom development in pine wilt disease. To ascertain this, we investigated the bacterial flora associated with the nematode and its possible roles in the disease by means of molecular biological techniques. As a result, the dominant bacterial species were different from those in past researches and none of them showed a significant pathogenicity against susceptible pine seedlings. On the other hand, one of the dominant species was frequently detected in seedlings inoculated with bacteriafree nematodes and in vector beetle-associated samples, indicating its possible involvement in the disease.
What induces the dispersal form of the PWN? How is the number of PWNs carried by a Monochamus beetle determined?
The effect of mycorrhizae as a resistance factor of pine trees [Pinus densiflora] to the pinewood nematode
Pine wilt disease is one of the most serious forest diseases in East Asian countries. The infecti... more Pine wilt disease is one of the most serious forest diseases in East Asian countries. The infection chain of this disease, which is filled with various biological relationships, is briefly reviewed. The affinity between host pine trees and pathogenic nematodes, one of the most decisive phases of the disease, is subsequently examined in a series of experiments.
Characteristics of Egg Shells and the Morphology of Female Tail-tips of Bursaphelenchus xylophilus, B. mucronatus and Some Strains of Related Species from France
Japanese Journal of Nematology, Dec 15, 1985
Fundamental and applied nematology, 1997
Acceptecl for publication 9July 1997. Summary -The Japanese pine sawyer, /VIonochamus ailernalUs,... more Acceptecl for publication 9July 1997. Summary -The Japanese pine sawyer, /VIonochamus ailernalUs, that emerged From blocks inoculated first with OphiosLOma minus then with Trichoderma sp. (O+T) carried more pinewood nematodes (PWN, Bursaphe/enchus xy/ophi/us) than those emerging From blocks inoculated with these two fungi simultaneously (O,T togeù1er) or inoculated first with Trichoderma (T+O). This was because: z) PWN populations were much larger in the O+T blocks than in the blocks with the other treatments, and ii) the percentage of third-stage dispersal juveniles, dauer juveniles, and PWN which actually transferred to the beetle were much higher in the O+T blocks. By contras t, the numbers of PWN carried by the beetles emerging From blocks inoculated with both 0. minus and Vérticil/ium sp. were much smaller regardless of the inoculation sequence because PWN populations did not build up. We conclude that the species of fungi which are most prevalent in pi ne wilt-killed trees will help determine the number of P\X!N carried by the beetles emerging from the wood. Résumé -Effets des interactions fongiques sur le nombre de Bursaphelenchus xylophilus (Ne1natoda: Aphelenchoididae) transportés par Monochamus alternatus (Coleoptera: Cerambycidae) -Monochamus a/lernaLUS sortant de blocs de bois préalablement inoculés avec OphiosLOma minus et ensuite avec Trichoderma sp. (0+T) transporte un plus grand nombre de Bursaphelenchus xy/ophilus (PWN) que ceux sortant de blocs inoculés simultanément avec ces deux champignons (0, T) ou inoculés avec Trichoderma sp. puis avec 0. minus (T +0). La raison en est que: 1) les populations de PWN sont plus élevées dans les blocs 0+ T que dans ceux des autres traitements, et que il) le pourcentage de juvéniles de dispersion de 3 e stade, les "dauer" juvéniles et les PWN qui passent réellement dans l'insecte sont plus nombreux dans les blocs O+T. En contraste, le nombre de PWN transportés par l'insecte sortant de blocs inoculés avec 0. minus et Umici/lium sp. est beaucoup moins élevé quelle que soit la séquence d'inoculum parce que les populations de PWN ne s'y établissent pas. Il est conclu que les espéces de champignons les plus abondantes dans les pins tués par le desséchement concourent à déterminer le nombre de PWN transportés par l'insecte sortant du bois.
PLOS ONE, Jun 21, 2013
Since it was first introduced into Asia from North America in the early 20 th century, the pine w... more Since it was first introduced into Asia from North America in the early 20 th century, the pine wood nematode Bursaphelenchus xylophilus has caused the devastating forest disease called pine wilt. The emerging pathogen spread to parts of Europe and has since been found as the causal agent of pine wilt disease in Portugal and Spain. In 2011, the entire genome sequence of B. xylophilus was determined, and it allowed us to perform a more detailed analysis of B. xylophilus parasitism. Here, we identified 1,515 proteins secreted by B. xylophilus using a highly sensitive proteomics method combined with the available genomic sequence. The catalogue of secreted proteins contained proteins involved in nutrient uptake, migration, and evasion from host defenses. A comparative functional analysis of the secretome profiles among parasitic nematodes revealed a marked expansion of secreted peptidases and peptidase inhibitors in B. xylophilus via gene duplication and horizontal gene transfer from fungi and bacteria. Furthermore, we showed that B. xylophilus secreted the potential host mimicry proteins that closely resemble the host pine's proteins. These proteins could have been acquired by host-parasite co-evolution and might mimic the host defense systems in susceptible pine trees during infection. This study contributes to an understanding of their unique parasitism and its tangled roots, and provides new perspectives on the evolution of plant parasitism among nematodes.
The infestation pattern of Platypus quercivorus on Fagus crenata
The Japanese Forest Society Congress, 2007
Making headway in understanding pine wilt disease: What do we perceive in the postgenomic era?
Journal of Bioscience and Bioengineering, Jul 1, 2013
The advent of next generation sequencing has revolutionized research approaches to biology by mak... more The advent of next generation sequencing has revolutionized research approaches to biology by making entire genome sequences available and marking a new age in biology that has the potential to open innovative research avenues in various fields. Genome sequencing is now being applied in the fields of forest ecology and forest pathology, which previously had limited access to molecular techniques. One of the most advanced areas of progress is the study of "pine wilt disease", which is caused by the parasitic nematode, Bursaphelenchus xylophilus. The entire genome sequence of B. xylophilus was determined in 2011, and since then, proteomic studies have been conducted to understand the molecular basis of the parasitism and pathogenicity of B. xylophilus. These postgenomic studies have provided numerous molecular insights and greatly changed our understanding of the pathogenesis of pine wilt disease. Here, we review the recent advances in genomic and proteomic approaches that address some of the longstanding questions behind the pathogenesis of pine wilt disease and have identified future questions and directions in this regard.
Regression analysis for the estimation of a sound seed ratio in Pinus thunbergii
Journal of The Japanese Forest Society, May 1, 1991
Biocontrol of Meloidogyne incognita on tomato using antagonistic fungi, plant-growth-promoting rhizobacteria and cattle manure
Pest Management Science, May 8, 2009
BACKGROUND: Biocontrol achieved by a single biocontrol agent is generally inconsistent under fiel... more BACKGROUND: Biocontrol achieved by a single biocontrol agent is generally inconsistent under field conditions. The aim of the present study was to increase the competitiveness and efficacy of biocontrol agents by using them together with cattle manure.RESULTS: The effects of antagonistic fungi [Aspergillus niger v. Teigh., Paecilomyces lilacinus (Thom) Samson and Penicillium chrysogenum Thom] and plant‐growth‐promoting rhizobacteria (PGPR) [Azotobacter chroococcum Beijer., Bacillus subtilis (Ehrenberg) Cohn and Pseudomonas putida (Trev.) Mig.] were assessed with cattle manure on the growth of tomato and on the reproduction of Meloidogyne incognita (Kof. & White) Chitwood. Application of antagonistic fungi and PGPR alone and in combination with cattle manure resulted in a significant increase in the growth of nematode‐inoculated plants. The highest increase (79%) in the growth of nematode‐inoculated plants was observed when P. putida was used with cattle manure, followed by use of P. lilacinus plus cattle manure. Paecilomyces lilacinus resulted in a high reduction in galling and nematode multiplication, followed by P. putida, B. subtilis, A. niger, A. chroococcum and P. chrysogenum. The combined use of P. lilacinus with cattle manure resulted in a maximum reduction in galling and nematode multiplication.CONCLUSION: Application of P. lilacinus or P. putida with cattle manure was useful to achieve greater biocontrol of M. incognita on tomato. Copyright © 2009 Society of Chemical Industry
Bursaphelenchus xylophilus and B. mucronatus in Japan: where are they from?
BRILL eBooks, 2004
ABSTRACT
Phylogenetic relationship among several isolates of Bursaphelenchus xylophilus and B. mucronatus based on their ribosomal DNA sequences
Nematology, 2007
The relationship between the pine wood nematode (PWN), Bursaphelenchus xylophilus, and fungi coha... more The relationship between the pine wood nematode (PWN), Bursaphelenchus xylophilus, and fungi cohabiting in 15-yearold Japanese black pine, Pinus thunbergii, was examined at intervals of 2 months over a year following inoculation with PWN. The population of PWN in the trees was large in August, but decreased slightly in December then increased again in February. Eighteen species of fungi were isolated from wood samples of the pine trees examined. Among them were Phialophora repens, Sphaeropsis sapinea, Pestalotiopsis spp. and Rhizoctonia sp., which were detected most frequently every season. All of these dominant fungi had positive effects on increasing the nematode population except for Rhizoctonia sp., on which PWN propagated less. Under laboratory conditions, 18 species of fungi isolated from pine trees and Botrytis cinerea cultured on potato dextrose agar served as food for PWN, and PWN population build up was compared at 20 • C. PWN increased significantly on Pestalotiopsis sp. 1, Pestalotiopsis sp. 2, Sphaeropsis sapinea, Phialophora repens and B. cinerea from 10-15 days after inoculation. From the viewpoint of food quality and their cohabiting ability, we concluded that the species of fungi that were dominant in the pine trees, except for Rhizoctonia sp., had a compatible relationship with PWN, whilst Rhizoctonia sp. and Penicillium spp. were neutral, and Trichoderma spp. had an incompatible relationship with PWN.
A simple, polymerase chain reaction-restriction fragment length polymorphism-aided diagnosis method for pine wilt disease
Forest Pathology, Jun 1, 2000
SummaryFor diagnosis of pine wilt disease, a simple PCR‐RFLP method was developed to identify and... more SummaryFor diagnosis of pine wilt disease, a simple PCR‐RFLP method was developed to identify and to differentiate two similar nematode species, based on a living or preserved single specimen. Pinewood nematodes, Bursaphelenchus xylophilus, and Bursaphelenchus mucronatus were examined. A single nematode in 1 µl of distilled water was put on a glass slide. When the water had almost dried the nematode was crushed with a filter paper chip, 1.5 mm × 1.5 mm, with the aid of forceps. The filter paper chip containing nematode remains was immediately placed into PCR buffer as the DNA template. The primer set used was to amplify ribosomal DNA containing the inter‐transcribed spacer (ITS) 1, 5.8S and ITS2 regions. The PCR product was consistently obtained from a single nematode, and digesting the product with restriction endonuclease, Hinf I, enabled discrimination between B. xylophilus and B. mucronatus. This method was simple, convenient and definitive, and could successfully determine the pathogen in the diagnosis of pine wilt disease. This method was applicable also to nematode specimens preserved under various conditions except in the case of those preserved in aldehyde‐containing fixatives.
The Relationship Between the Pinewood Nematode (PWN) and Fungi Cohabiting in aine Trees Inoculated with the PWN
Springer eBooks, Aug 27, 2008
... Although the dominant fungi were constantly detected over the experimental period, the compos... more ... Although the dominant fungi were constantly detected over the experimental period, the composi-tion of fungal species slightly varied among seasons as reported in previous studies (Kobayashi et al., 1974, 1975; Fukushige and Futai, 1987; Kuroda and Ito, 1992). ...
A comprehensive understanding of pine wilt disease
Journal of Nanjing Forestry University, 2010
Mortality of Quercus laurifolia trees that had been planted in Japan occurred in. This was caused... more Mortality of Quercus laurifolia trees that had been planted in Japan occurred in. This was caused by an attack by the ambrosia beetle Platypus quercivorus, which causes a disease called Japanese oak wilt and results in mass mortality of Fagaceae trees in Japan. In order to study the infestation of Q. laurifolia by P. quercivorus, dead trees were cut into bolts, and the density of holes bored by P. quercivorus was examined for each bolt. Tube traps were attached to each hole in the bolts of the cut trees, and the number of offspring that emerged from the hole during (the year following the infestation) was counted. Similar to other Japanese Fagaceae species, the density of holes bored by P. quercivorus decreased with increase in the height of Q. laurifolia. The sex ratio of the emerged beetle was biased towards males, and the number of offspring per hole ranged from to. The effects of the height and the hole density on the number of offspring were analyzed with zero-altered negative binomial models with a hurdle component and a truncated count component. The results of the hurdle component in the model for zero counts showed that the probability that one or more beetles emerged from holes was negatively affected by the height above the ground. According to the results of the count component of the model for positive counts, the number of offspring showed a unimodal distribution, with a peak at around one in the density of holes per cm. Japanese oak wilt, laurel oak, reproductive success rate, zero-altered negative binomial model Quercus laurifolia Platypus quercivorus zero-altered negative binomial model cm zero-altered negative binomial model
Agrivita : Journal of Agricultural Science, Oct 1, 2012
Beetle activity deep inside wood was studied in field (Mt. Yoshida, Kyoto) and laboratory conditi... more Beetle activity deep inside wood was studied in field (Mt. Yoshida, Kyoto) and laboratory conditions by monitoring the type and amount of frass ejected from beetle galleries of Platypus quercivorus. Twenty-one galleries were selected from five infested Quercus serrata trees for field studies. In the laboratory, frass production was monitored for three galleries using a computer-aided electrical balance (A&D Co. Ltd.). Long-term patterns of frass production from field observation revealed that there are three distinguishable stages; a fibrous frass stage, an intermediate stage, and a powdery frass stage. The duration of the fibrous frass production was clearly different between galleries, ranging from five to twenty one days. The intermediate stage was also different from gallery to gallery, ranging from two to twenty days. Accordingly, the starting time of the third stage, powdery frass production, ranged from the 19 th to the 27 th day. Under laboratory conditions, the longterm patterns of frass production revealed that in galleries of logs no. 1 and 2 the fibrous frass period was stopped on the 23 rd and 22 nd day, respectively. Field monitoring revealed there was a negative relationship between the length of fibrous frass stage and the length of the intermediate stage.
Pine wood nematode, Bursaphelenchus xylophilus, exhibits a wide range of intraspecific variation ... more Pine wood nematode, Bursaphelenchus xylophilus, exhibits a wide range of intraspecific variation in several biological traits. Among them virulence (degree of pathogenicity), reproductive ability and boarding ability on the vector beetle are important pathogenicityrelated traits, although their molecular basis has not been determined. In this study we generated a set of recombinant inbred lines (RILs) of B. xylophilus from two inbred lines, F7 and P9, which greatly differ in the degree of pathogenicity. In addition, we conducted bioassays to estimate above-mentioned three traits in the newly obtained 17 RILs and two parental inbred lines. As a result, RILs showed various virulences and reproductions along a continuum and two distinct transmission abilities. This indicates that virulence and reproduction may be quantitative, polygenic trait, while transmission ability is a qualitative trait which is controlled by a single or few genes.
In recent years a hypothesis was proposed that not pine wood nematode, but its accompanying bacte... more In recent years a hypothesis was proposed that not pine wood nematode, but its accompanying bacteria is responsible for the symptom development in pine wilt disease. To ascertain this, we investigated the bacterial flora associated with the nematode and its possible roles in the disease by means of molecular biological techniques. As a result, the dominant bacterial species were different from those in past researches and none of them showed a significant pathogenicity against susceptible pine seedlings. On the other hand, one of the dominant species was frequently detected in seedlings inoculated with bacteriafree nematodes and in vector beetle-associated samples, indicating its possible involvement in the disease.
What induces the dispersal form of the PWN? How is the number of PWNs carried by a Monochamus beetle determined?
The effect of mycorrhizae as a resistance factor of pine trees [Pinus densiflora] to the pinewood nematode
Pine wilt disease is one of the most serious forest diseases in East Asian countries. The infecti... more Pine wilt disease is one of the most serious forest diseases in East Asian countries. The infection chain of this disease, which is filled with various biological relationships, is briefly reviewed. The affinity between host pine trees and pathogenic nematodes, one of the most decisive phases of the disease, is subsequently examined in a series of experiments.
Characteristics of Egg Shells and the Morphology of Female Tail-tips of Bursaphelenchus xylophilus, B. mucronatus and Some Strains of Related Species from France
Japanese Journal of Nematology, Dec 15, 1985