The Experts below are selected from a list of 10290 Experts worldwide ranked by ideXlab platform
Koji Kageyama - One of the best experts on this subject based on the ideXlab platform.
-
seedling blight of glycyrrhiza uralensis caused by Pythium myriotylum p aphanidermatum and p spinosum and identifying primary inoculum sources using multiplex pcr detection
Journal of General Plant Pathology, 2014Co-Authors: Yasushi Ishiguro, Haruhisa Suga, Kayoko Otsubo, Minoru Watarai, Tatsuro Iwashita, Masahiro Tomita, Masaru Suematsu, Hirokazu Fukui, Koji KageyamaAbstract:Pythium species, isolated from seedlings of Glycyrrhiza uralensis with blight, were identified as P. myriotylum, P. aphanidermatum, and P. spinosum on the basis of morphological characteristics and sequences of the internal transcribed spacer regions of rDNA. In pathogenicity tests, the isolates of the three Pythium species caused blight, producing the original disease symptoms. The primary inoculum source was determined using a multiplex PCR to detect the pathogen. All the Pythium species were detected in the soils of fields with the diseased plants and in soils of adjacent field soils.
-
development of multiplex pcr to detect five Pythium species related to turfgrass diseases
Journal of Phytopathology, 2010Co-Authors: Takahiro Asano, Masako Senda, Haruhisa Suga, Koji KageyamaAbstract:The objective of this study was to develop multiplex PCR detection method for five Pythium species associated with turfgrass diseases, Pythium aphanidermatum, Pythium arrhenomanes, Pythium graminicola, Pythium torulosum and Pythium vanterpoolii. Species-specific primers and two common primers were designed based on the sequences of the internal transcribed spacer region of ribosomal DNA. Another primer set by which all organisms would be amplified in 18S rDNA was used as a positive control. When these total nine primers were applied to the multiplex PCR, all species were individually discriminated in the mixture of five species culture DNA. Furthermore, all five Pythium species were detected in naturally infected plants using the multiplex PCR.
-
Pythium and Phytophthora species associated with root and stem rots of kalanchoe
Journal of General Plant Pathology, 2007Co-Authors: Hideki Watanabe, Mitsuro Hyakumachi, Yoshihiro Taguchi, Koji KageyamaAbstract:Pythium and Phytophthora species were isolated from kalanchoe plants with root and stem rots. Phytophthora isolates were identified as Phytophthora nicotianae on the basis of morphological characteristics and restriction fragment length polymorphism (RFLP) analysis of the rDNA-internal transcribed spacer regions. Similarly, the Pythium isolates were identified as Pythium myriotylum and Pythium helicoides . In pathogenicity tests, isolates of the three species caused root and stem rots. Disease severity caused by the Pythium spp. and Ph. nicotianae was the greatest at 35°–40°C and 30°–40°C, respectively. Ph. nicotianae induced stem rot at two different relative humidities (60% and >95%) at 30°C. P. myriotylum and P. helicoides caused root and stem rots at high humidity (>95%), but only root rot at low humidity (60%).
-
phylogenetic relationships of Pythium and phytophthora species based on its rdna cytochrome oxidase ii and β tubulin gene sequences
Mycologia, 2006Co-Authors: Neilyn O Villa, Koji Kageyama, Takahiro Asano, Haruhisa SugaAbstract:Fifty-eight isolates representing 39 Pythium species and 17 isolates representing nine Phytophthora species were chosen to investigate intra- and intergeneric relationships with sequence analysis of three genomic areas. The internal transcribed spacer regions (ITS1 and ITS2), including the 5.8S gene of the ribosomal DNA were PCR amplified with the universal primers ITS1 and ITS4. On the other hand 563 bp of the cytochrome oxidase II (cox II) gene was amplified with the primer pair FM66 and FM58 for Pythium and FM75 and FM78 for Phytophthora. The 658 bp partial beta-tubulin gene was amplified with the forward primer BT5 and reverse primer BT6. Maximum parsimony analysis of the three DNA regions revealed four major clades, reflective of sporangial morphology. Clade 1 was composed of Pythium isolates that bear filamentous to lobulate sporangia. Clade 2 represents Pythium isolates that bear globose to spherical zoosporangia or spherical hyphal swellings. Meanwhile Phytophthora isolates were lumped into Clade 3 wherein the papillate, semipapillate and nonpapillate species occupied separate subclades. Lastly, Clade 4 was composed of Pythium species that bear subglobose sporangia resembling the papillate sporangia observed in Phytophthora. Hence a number of species (Ph. undulata, P. helicoides, P. ostracodes, P. oedochilum and P. vexans) have been proposed to be the elusive intermediate species in the Pythium-to-Phytophthora evolutionary line.
-
phylogenetic relationships of Pythium and phytophthora species based on its rdna cytochrome oxidase ii and beta tubulin gene sequences
Mycologia, 2006Co-Authors: Neilyn O Villa, Koji Kageyama, Takahiro Asano, Haruhisa SugaAbstract:Fifty-eight isolates representing 39 Pythium species and 17 isolates representing nine Phytophthora species were chosen to investigate intra- and intergeneric relationships with sequence analysis of three genomic areas. The internal transcribed spacer regions (ITS1 and ITS2), including the 5.8S gene of the ribosomal DNA were PCR amplified with the universal primers ITS1 and ITS4. On the other hand 563 bp of the cytochrome oxidase II (cox II) gene was amplified with the primer pair FM66 and FM58 for Pythium and FM75 and FM78 for Phytophthora. The 658 bp partial beta-tubulin gene was amplified with the forward primer BT5 and reverse primer BT6. Maximum parsimony analysis of the three DNA regions revealed four major clades, reflective of sporangial morphology. Clade 1 was composed of Pythium isolates that bear filamentous to lobulate sporangia. Clade 2 represents Pythium isolates that bear globose to spherical zoosporangia or spherical hyphal swellings. Meanwhile Phytophthora isolates were lumped into Clade 3 wherein the papillate, semipapillate and nonpapillate species occupied separate subclades. Lastly, Clade 4 was composed of Pythium species that bear subglobose sporangia resembling the papillate sporangia observed in Phytophthora. Hence a number of species (Ph. undulata, P. helicoides, P. ostracodes, P. oedochilum and P. vexans) have been proposed to be the elusive intermediate species in the Pythium-to-Phytophthora evolutionary line.
Haruhisa Suga - One of the best experts on this subject based on the ideXlab platform.
-
seedling blight of glycyrrhiza uralensis caused by Pythium myriotylum p aphanidermatum and p spinosum and identifying primary inoculum sources using multiplex pcr detection
Journal of General Plant Pathology, 2014Co-Authors: Yasushi Ishiguro, Haruhisa Suga, Kayoko Otsubo, Minoru Watarai, Tatsuro Iwashita, Masahiro Tomita, Masaru Suematsu, Hirokazu Fukui, Koji KageyamaAbstract:Pythium species, isolated from seedlings of Glycyrrhiza uralensis with blight, were identified as P. myriotylum, P. aphanidermatum, and P. spinosum on the basis of morphological characteristics and sequences of the internal transcribed spacer regions of rDNA. In pathogenicity tests, the isolates of the three Pythium species caused blight, producing the original disease symptoms. The primary inoculum source was determined using a multiplex PCR to detect the pathogen. All the Pythium species were detected in the soils of fields with the diseased plants and in soils of adjacent field soils.
-
development of multiplex pcr to detect five Pythium species related to turfgrass diseases
Journal of Phytopathology, 2010Co-Authors: Takahiro Asano, Masako Senda, Haruhisa Suga, Koji KageyamaAbstract:The objective of this study was to develop multiplex PCR detection method for five Pythium species associated with turfgrass diseases, Pythium aphanidermatum, Pythium arrhenomanes, Pythium graminicola, Pythium torulosum and Pythium vanterpoolii. Species-specific primers and two common primers were designed based on the sequences of the internal transcribed spacer region of ribosomal DNA. Another primer set by which all organisms would be amplified in 18S rDNA was used as a positive control. When these total nine primers were applied to the multiplex PCR, all species were individually discriminated in the mixture of five species culture DNA. Furthermore, all five Pythium species were detected in naturally infected plants using the multiplex PCR.
-
phylogenetic relationships of Pythium and phytophthora species based on its rdna cytochrome oxidase ii and β tubulin gene sequences
Mycologia, 2006Co-Authors: Neilyn O Villa, Koji Kageyama, Takahiro Asano, Haruhisa SugaAbstract:Fifty-eight isolates representing 39 Pythium species and 17 isolates representing nine Phytophthora species were chosen to investigate intra- and intergeneric relationships with sequence analysis of three genomic areas. The internal transcribed spacer regions (ITS1 and ITS2), including the 5.8S gene of the ribosomal DNA were PCR amplified with the universal primers ITS1 and ITS4. On the other hand 563 bp of the cytochrome oxidase II (cox II) gene was amplified with the primer pair FM66 and FM58 for Pythium and FM75 and FM78 for Phytophthora. The 658 bp partial beta-tubulin gene was amplified with the forward primer BT5 and reverse primer BT6. Maximum parsimony analysis of the three DNA regions revealed four major clades, reflective of sporangial morphology. Clade 1 was composed of Pythium isolates that bear filamentous to lobulate sporangia. Clade 2 represents Pythium isolates that bear globose to spherical zoosporangia or spherical hyphal swellings. Meanwhile Phytophthora isolates were lumped into Clade 3 wherein the papillate, semipapillate and nonpapillate species occupied separate subclades. Lastly, Clade 4 was composed of Pythium species that bear subglobose sporangia resembling the papillate sporangia observed in Phytophthora. Hence a number of species (Ph. undulata, P. helicoides, P. ostracodes, P. oedochilum and P. vexans) have been proposed to be the elusive intermediate species in the Pythium-to-Phytophthora evolutionary line.
-
phylogenetic relationships of Pythium and phytophthora species based on its rdna cytochrome oxidase ii and beta tubulin gene sequences
Mycologia, 2006Co-Authors: Neilyn O Villa, Koji Kageyama, Takahiro Asano, Haruhisa SugaAbstract:Fifty-eight isolates representing 39 Pythium species and 17 isolates representing nine Phytophthora species were chosen to investigate intra- and intergeneric relationships with sequence analysis of three genomic areas. The internal transcribed spacer regions (ITS1 and ITS2), including the 5.8S gene of the ribosomal DNA were PCR amplified with the universal primers ITS1 and ITS4. On the other hand 563 bp of the cytochrome oxidase II (cox II) gene was amplified with the primer pair FM66 and FM58 for Pythium and FM75 and FM78 for Phytophthora. The 658 bp partial beta-tubulin gene was amplified with the forward primer BT5 and reverse primer BT6. Maximum parsimony analysis of the three DNA regions revealed four major clades, reflective of sporangial morphology. Clade 1 was composed of Pythium isolates that bear filamentous to lobulate sporangia. Clade 2 represents Pythium isolates that bear globose to spherical zoosporangia or spherical hyphal swellings. Meanwhile Phytophthora isolates were lumped into Clade 3 wherein the papillate, semipapillate and nonpapillate species occupied separate subclades. Lastly, Clade 4 was composed of Pythium species that bear subglobose sporangia resembling the papillate sporangia observed in Phytophthora. Hence a number of species (Ph. undulata, P. helicoides, P. ostracodes, P. oedochilum and P. vexans) have been proposed to be the elusive intermediate species in the Pythium-to-Phytophthora evolutionary line.
Mary K. Hausbeck - One of the best experts on this subject based on the ideXlab platform.
-
characterization of Pythium species associated with greenhouse floriculture crops in michigan
Plant Disease, 2016Co-Authors: Johanna Del Castillo Munera, Mary K. HausbeckAbstract:Michigan ranks third in the United States for the wholesale value of floriculture products, with an estimated value of $375.7 million. Seedling damping-off and root and crown rot are commonly caused by Pythium spp. and are important problems for greenhouse growers. Pythium spp. associated with Michigan’s floriculture crops were characterized as a means to improve current management strategies. During 2011 and 2012, potted poinsettias with root rot symptoms were sampled from nine greenhouses located in Kent, Kalamazoo, and Wayne counties. In 2013, from the same three counties, symptomatic geranium and snapdragon bedding plants were sampled from 12 greenhouses. Additionally, symptomatic hibiscus and lantana plants were sampled at one greenhouse facility. Isolates were confirmed to be Pythium spp. via morphology and sequencing of the ITS region. A total of 287 Pythium spp. isolates were obtained from poinsettias and 726 isolates from geranium, snapdragon, hibiscus, and lantana. Seven Pythium spp., and a grou...
-
characterization of Pythium species associated with greenhouse floriculture crops in michigan
Plant Disease, 2016Co-Authors: Johanna Del Castillo Munera, Mary K. HausbeckAbstract:Michigan ranks third in the United States for the wholesale value of floriculture products, with an estimated value of $375.7 million. Seedling damping-off and root and crown rot are commonly caused by Pythium spp. and are important problems for greenhouse growers. Pythium spp. associated with Michigan's floriculture crops were characterized as a means to improve current management strategies. During 2011 and 2012, potted poinsettias with root rot symptoms were sampled from nine greenhouses located in Kent, Kalamazoo, and Wayne counties. In 2013, from the same three counties, symptomatic geranium and snapdragon bedding plants were sampled from 12 greenhouses. Additionally, symptomatic hibiscus and lantana plants were sampled at one greenhouse facility. Isolates were confirmed to be Pythium spp. via morphology and sequencing of the ITS region. A total of 287 Pythium spp. isolates were obtained from poinsettias and 726 isolates from geranium, snapdragon, hibiscus, and lantana. Seven Pythium spp., and a group of isolates determined as Pythium sp. 1 were identified. The most prevalent species were P. irregulare, P. ultimum, and P. aphanidermatum. A subset of isolates was chosen for pathogenicity and mefenoxam sensitivity testing. Six of the species were virulent to germinating geranium seeds. Most P. ultimum and P. cylindrosporum isolates tested were intermediate to highly resistant to mefenoxam, whereas most P. aphanidermatum isolates were sensitive. This study suggests that Pythium spp. recovered from Michigan greenhouses may vary depending on the host, and that mefenoxam may not be effective to control P. ultimum or P. cylindrosporum.
Motoaki Tojo - One of the best experts on this subject based on the ideXlab platform.
-
surviving freezing in plant tissues by oomycetous snow molds
Cryobiology, 2015Co-Authors: Ryo Murakami, Motoaki Tojo, Tamotsu Hoshino, Yuka Yajima, Kenichi Kida, Katsuyuki TokuraAbstract:Oomyceteous snow molds, Pythium species, were reported to be less tolerant to chilling and freezing temperatures than other snow mold taxa. However, Pythium species are often found to be pathogenic on mosses in Polar Regions. We investigated the frost resistance of Pythium species from Temperate (Hokkaido, Japan) and Subantarctic Regions. Free mycelia and hyphal swellings, structures for survival, of Pythium iwayamai and Pythium paddicum lost viability within freeze-thaw 3 cycles; however, mycelia in host plants survived the treatment. It was reported that fungi in permafrost are characterized both by the presence of natural cryoprotectants in these ecotopes and by the ability to utilize their inherent mechanisms of protection. It is conceivable that plant substrates or derivatives thereof are natural cryoprotectants, enabling them to provide advantageous conditions to microorganisms under freezing conditions. Our results are the first to experimentally support this hypothesis.
-
modifications of parp medium using fluazinam miconazole and nystatin for detection of Pythium spp in soil
Plant Disease, 2007Co-Authors: Y Morita, Motoaki TojoAbstract:The standard Pythium selective medium PARP (pimaricin + ampicillin + rifampicin + pentachloronitrobenzene [PCNB] agar), was modified by replacing PCNB and pimaricin with other antifungal agents. Several antifungal agents such as fluazinam, miconazole, 2,4,5,6-tetrachloroisophthalonitrile (TPN), iminoctadine triacetate, tolclofos-methyl, captan, and nystatin, initially were screened for effects on Pythium growth. Based on these results, the following three media were developed: PARF (pimaricin + ampicillin + rifampicin + fluazinam agar), NARF (nystatin + ampicillin + rifampicin + fluazinam agar), and NARM (nystatin + ampicillin + rifampicin + miconazole agar). New media were comparable with PARP on yield of naturally occurring Pythium spp. from two different types of soil using the soil-dilution plating technique. PARF and NARF were significantly better than PARP on inhibition of non-pythiaceous microbes on the soil-dilution plates, but were significantly lower than PARP on the rate of mycelial growth of six of eight isolates belonging to seven species of Pythium. NARM was equivalent to PARP on inhibition of non-pythiaceous microbes except for Fusarium oxysporum, and was significantly better than PARP on rate of mycelial growth of five of eight isolates of Pythium.
-
Pythium rot of chingensai brassica campestris l chinensis group caused by Pythium ultimum var ultimum and Pythium aphanidermatum
Journal of General Plant Pathology, 2004Co-Authors: Koji Tanina, Motoaki Tojo, H. Date, H Nasu, S KasuyamaAbstract:Severe rot was found at the base of leaves and stems of chingensai (Brassica campestris L. chinensis group) in Okayama Prefecture in 2000. The causal fungi were morphologically identified as Pythium ultimum Trow var. ultimum and P. aphanidermatum (Edson) Fitzpatrick. This is the first report of rot caused by Pythium species on chingensai. We named this disease Pythium rot of chingensai.
-
Pythium rot of chingensai brassica campestris l chinensis group caused by Pythium ultimum var ultimum and Pythium aphanidermatum
Journal of General Plant Pathology, 2004Co-Authors: Koji Tanina, Motoaki Tojo, H. Date, H Nasu, S KasuyamaAbstract:Severe rot was found at the base of leaves and stems of chingensai (Brassica campestris L. chinensis group) in Okayama Prefecture in 2000. The causal fungi were morphologically identified as Pythium ultimum Trow var. ultimum and P. aphanidermatum (Edson) Fitzpatrick. This is the first report of rot caused by Pythium species on chingensai. We named this disease Pythium rot of chingensai.
Jack Brown - One of the best experts on this subject based on the ideXlab platform.
-
initial Pythium species composition and brassicaceae seed meal type influence extent of Pythium induced plant growth suppression in soil
Soil Biology & Biochemistry, 2012Co-Authors: Mark Mazzola, Catherine L Reardon, Jack BrownAbstract:The composition of Pythium spp. communities differs among orchard soils resulting in variation in the relative importance of these pathogens to development of the biologically complex apple replant disease. Brassicaceae seed meal (SM) amendments differentially influence quantitative dynamics of Pythium populations resident to soil systems. Studies were conducted to determine the effect of initial species composition and Brassicaceae and non-Brassicaceae SM type on qualitative attributes of Pythium spp. communities and resulting effects on plant growth and disease development in two orchard soils (Soil 1 and Soil 2). Quantitatively, Pythium densities were similar between two study soils, but apple seedling mortality and suppression of wheat emergence were only observed in Soil 1. Correspondingly, application of Pythium suppressive Brassica juncea SM only improved emergence and reduced seedling mortality in Soil 1. Although Brassica napus, Glycine max and Sinapis alba SM amendments consistently elevated Pythium spp. soil densities, the corresponding effect on plant growth was more deleterious in Soil 1 than Soil 2. These differences corresponded with the initial Pythium species composition resident to the soils, with highly virulent Pythium ultimum var. ultimum dominant in Soil 1 and less virulent Pythium heterothallicum most prevalent in Soil 2. Although Pythium densities were lower in Soil 2 amended with S. alba than B. napus SM, plant damage consistently was greater in S. alba amended soil. This result corresponded with the finding that S. alba SM application preferentially elevated recovery of P. ultimum var. ultimum from Soil 2 and the roots of plants grown in this soil while less virulent species continued to dominate B. napus SM treated soil. The effect of SM type on Pythium soil densities as well as species composition should be considered to effectively employ Brassicaceae seed meals as a fertility management or soilborne disease control strategy in plant production systems.
-
interaction of brassicaceous seed meal and apple rootstock on recovery of Pythium spp and pratylenchus penetrans from roots grown in replant soils
Plant Disease, 2009Co-Authors: Jack Brown, Xiaowen Zhao, Antonio D Izzo, Gennaro FazioAbstract:ABSTRACT Pythium spp. and Pratylenchus penetrans are significant components of the diverse pathogen complex that incites apple replant disease in Washington State. The structure of the Pythium population differs among orchard soils but is composed of multiple pathogenic species. Studies were conducted to determine the effect of brassicaceous seed meals and apple rootstock on the activity and composition of these pathogen populations. Brassicaceous seed meals differed in capacity to suppress Pythium numbers and apple root infection, as well as differentially transformed composition of the population recovered from apple roots. Brassica juncea seed meal (SM) was the sole seed meal examined to suppress Pythium numbers and root infection; however, a persisting population was always detected in which Pythium irregulare existed as the dominant or co-dominant species. In general, the Geneva series rootstocks were less susceptible to root infection by native populations of Pythium, whereas M26, MM106, and MM111 w...
