Japanese Journal of Phytopathology
Online ISSN : 1882-0484
Print ISSN : 0031-9473
ISSN-L : 0031-9473
Volume 47 , Issue 4
Showing 1-23 articles out of 23 articles from the selected issue
  • Choei OGIMI, Hiroshi HIGUCHI
    1981 Volume 47 Issue 4 Pages 443-448
    Published: September 25, 1981
    Released: May 26, 2009
    JOURNALS FREE ACCESS
    A new bacterial disease was found on Myrica rubra S. et Z. growing in Okinawa, Shizuoka, Fukuoka, Mie, Tokushima prefecture, Japan. Galls with size of one to several cm in diameter and very rough surface were formed on either trunks or twigs. Small galls were also found on leaf petioles. The causal bacterium was pathogenic only on Myrica rubra, but not on the other plants belonged to 35 families and 69 species. The bacterium was a gram-negative rod with 1 to several polar flagella and 56.67 GC moles % of DNA. It was an aerobe and metabolized glucose oxidatively. Negative results were obtained with the tests such as nitrate reduction, gelatin liquefaction, H2S production, indol production, production of fluorescent pigment, arginine dihydrolase, Kovács' oxidase, starch hydrolysis, KCN inhibition and growth at 41 C. However, fluorescent pigment was produced when stiff agar was used instead of powdered agar. Positive reaction were obtained with the tests such as catalase reaction, tobacco hypersensitivity, levan formation, and hydrolysis of Tween 80. The following carbohydrates and an amino acid were utilized as a sole source of carbon: xylose, glucose, mannose, galactose, sucrose, fructose, glycerol, mannitol, arabinose, tartrate, citrate, malate, succinate, L-arginine. The carbon sources unused were as follow: lactose, maltose, trehalose, salicin, rhamnose, malonate, L-valine and β-alanine. Litmus milk turned blue and decolored later. The optimum growth temp. was 25-30 C, and the minium 4.5 C. Growth occurred at 4% NaCl but not at 5%. From these bacteriological characteristics, the authors inclined to identify the present bacterium as a new pathovar of Pseudomonas syringae and named Pseudomonas syringae pv. myricae pv. nov. Culture no. MR 1 was proposed as the pathotype strain and deposited to The American Type Culture Collection (No.33544), U.S.A., National Collection of Plant Pathogenic Bacteria (No.3143), England and Plant Disease Division Culture Collection (No.7118), New Zealand, respectively.
    Download PDF (2808K)
  • Tsuneo WATANABE
    1981 Volume 47 Issue 4 Pages 449-456
    Published: September 25, 1981
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Pythium spp. were isolated from soils and roots of various plants collected in the northern (Tohoku district) and southern (the Ryukyu Islands) parts of Japan that were studied for the distribution, kinds of species, and the populations. Isolations of Pythium from soils were conducted by the trapping method using cucumber, lupin, and corn seeds as trapping substrates, and a modification of Waksman's direct inoculation method using water agar as an isolation medium. Pythium spp. were found in 25 out of 27 soil samples of Tohoku district, and all of 21 samples of the Ryukyu Islands. Kinds of Pythium spp. were different according to the temperatures at the isolation procedure by the trapping method. Pythium aphanidermatum with an optimum temperature of 35C occupied 10 out of 43 isolates obtained at 36C and one out of 150 isolates at 20 and 7C for Tohoku isolates, whereas for the Ryukyu isolates, it occupied 37 out of 106 at 24C, but no isolate was obtained at 7C. This fungus was also isolated from 6 out of 11 plant species collected in both districts. A total of 52 plant isolates, 37 from Tohoku district and 15 from the Ryukyu Islands, were studied on temperature responses and it was found that Pythium spp. with high optimum temperatures for growth were more abundant in the latter isolates than in the former. Quantitative data were obtained by the modified direct inoculation method, and there were less than 50 propagules of Pythium spp. per g of soil, 51-200, and 201-1040 in the respective 19, 17, and 12 out of 48 samples assayed. Isolates of Pythium from soils and roots of various plants in both districts were identified at least to 13 and 8 species, respectively.
    Download PDF (389K)
  • Nobuaki MATSUYAMA, Tomio YAMAGUCHI
    1981 Volume 47 Issue 4 Pages 457-463
    Published: September 25, 1981
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Serial transfer of Pyricularia oryzae on PSA slant during 4 years caused decrease of aggressiveness and loss or acquirement of virulence. Monoconidialy re-isolated lines from isolate which appeared as not to be varied were, in some cases, heterogeneous in virulence and/or aggressiveness. Alteration was affected by frequency of transferring, volume of culture medium and constituents of medium. Frequent renewal of medium was commonly unfavorable. Although synthetic medium was better than PSA, the variation also occurred at 3rd year of storage. Rice node method is better than serial transfer on PSA slant. Around 60-70% stocks, however, died or contaminated during storage in -10 C for 4-10 years. A simple and reliable method for preservation of this fungus was investigated. Dried mycelial discs were viable, at least, for 5 years of preservation in small vials desiccated with silica gel under 5 to -10 C.
    Download PDF (368K)
  • Teruyoshi HASHIBA, Masao YAMADA
    1981 Volume 47 Issue 4 Pages 464-471
    Published: September 25, 1981
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Sclerotia of Rhizoctonia solani (Sasakii type) formed on rice plants were more resistant to high temperature and high humidity levels than those formed on potato-sucrose-agar (PSA). Sclerotia formed on rice plants has high proportions of “empty” cells in their outer layer, while the outer layer of sclerotia formed on PSA was narrower. The carbon dioxide content in gas from the tissues of sclerotia formed on rice plants was about 3 times than in ambient air. When sclerotia formed on PSA were stored at 25C under 70 and 80% relative humidity at various concentrations of carbon dioxide, viability of sclerotia held in air containing 0.1 and 0.15% carbon dioxide remained at the highest level similar to that of sclerotia formed on rice plants. The role of the structure in the viability of sclerotia is discussed.
    Download PDF (928K)
  • Norifusa MATSUO, Nobuaki MATSUYAMA, Satoshi WAKIMOTO
    1981 Volume 47 Issue 4 Pages 472-479
    Published: September 25, 1981
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    An antibacterial substance which is only effective to homologous isolate was released from bacterial cells of Xanthomonas campestris pv. citri Ku 7101 by heat treatment. The substance was dialyzable through Visking tube and stable to DNase, RNase, Trypsin, Pronase treatment and heating at 120 C for 30min. This substance was eluted from active carbon column by 20-25% ethanol and antibacterial activity of eluates was correlated with intensity of anthrone color reaction. This fraction showed single spot on thin layer chromatogram. The active substance was positive to naphthoresorcinol and sulfuric acid, suggesting that the substance could be mainly composed of sugars.
    The antibacterial substance considerably inhibited multiplication of X. campestris pv. citri Ku 7101 in liquid medium and ghost cells were observed with high frequency under electron microscope. The substance, however, was inactive against resting cells in phosphate buffer.
    Download PDF (2687K)
  • Norifusa MATSUO, Nobuaki MATSUYAMA, Satoshi WAKIMOTO
    1981 Volume 47 Issue 4 Pages 480-487
    Published: September 25, 1981
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    An antibacterial substance released from cells of Xanthomonas campestris pv. citri Ku 7508 by chloroform treatment was purified and its several properties were examined. The substance was not precipitated by centrifuging even at 60, 000×g for 60min, partially precipitated at 75% acetone (final concentration) and completely precipitated at 60% saturation with ammonium sulfate. It was not dialysed through Visking tube and inactivated by heating at 60 C for 30min. The purification of this substance was conducted by DEAE ion-exchange cellulose column followed by Ultrogel column. Antibacterial activity of eluates was corresponded with the peak of UV absorbance at 280nm. A typical UV spectrum of protein, i.e., maximum at 280nm and minimum at 250 nm was observed. Two or three bands were detected by Coomassie-blue staining at disc gel electrophoresis of this active fraction. One of the band having antibacterial activity was sliced and repeatedly subjected to disc gel electrophoresis and single band was isolated. Molecular weight of this substance estimated by SDS-polyacrylamide gel electrophoresis was about 300, 000 daltons. Antibacterial substance caused retardation of bacterial growth due to aggregation or disruption of cells during the first several hr. The effet, however, disappeared within 24hr of incubation. Electron microscopic observation revealed that the antibacterial substance caused leaking of bacterial cytoplasm due to disruption of cell wall. These results suggest that the antibacterial substance was a kind of bacteriocin.
    Download PDF (2150K)
  • Pyoyun PARK, Syoyo NISHIMURA, Keisuke KOHMOTO, Hiroshi OTANI
    1981 Volume 47 Issue 4 Pages 488-500
    Published: September 25, 1981
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Susceptible plant tissues were treated with several host-specific toxins from host-selective pathotypes of Alternaria alternata. Three different types of toxin-induced changes were detected by electron microscopy. The first and most common type was toxin-induced change in the plasma membrane. Many invaginations appeared in the membrane, along with much fragmentation and vesiculation. Cell walls were degraded, and desmotubules extended from plasmodesmata. Such effects were induced by AK-toxin in pear petals in addition to leaves, by AM-toxin I in apple and pear leaves, by AF-toxin I in strawberry and pear leaves, and by AF-toxin II in pear leaves. The initial effects in this type of response appeared to be at the interface between the cell wall and the plasma membrane. The second type of response to a toxin was a change in the chloroplast, resulting in detachment and vesiculation of grana lamellae; this response was induced by AM-toxin I in apple and pear leaves. A third type occurred in tomato leaves exposed to AL-toxin ; the mitochondria became swollen, the mitochondrial cristae were reduced and the matrix appeared to be leached. In addition, the endoplasmic reticulum was swollen and vesiculated. AF-toxin II caused collapse of cells in leaf veins of strawberry, but the electron micrographs did not show the location of early cellular effects. Electron micrographs showed no effects of the toxins on cells of resistant host genotypes.
    Download PDF (3198K)
  • Osamu HORINO
    1981 Volume 47 Issue 4 Pages 501-509
    Published: September 25, 1981
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    It is generally known that Kogyoku is moderately susceptible at seedling stage, and highly resistant at adult stage to bacterial group I of Xanthomonas campestris pv. oryzae. IR 28 and Te-tep, however, show a high level of resistance at both seedling and adult stages to bacterial group I. Hence, the purpose of the present study was to determine the ultrastructures in the resistance expression of Kogyoku, IR 28 and Te-tep varieties to bacterial group I at seedling stage. Inoculation was made at the fourth leaf stage by double needle-pricking method. Leaf samples were collected 3days after inoculation and ultrathin sections of them were observed under electron microscope. Bacterial cells were found normal and multipling in the xylem vessels of variety Kogyoku. The vascular parenchyma cells adjacent to vessels, cell organelles and cell wall appeared to be intact, similar to the healthy leaves. In the vessels of IR 28 and Te-tep, however, bacterial cells were irregular in shape and enveloped by abundant fibrillar material (FM) which was not observed in the vessels of Kogyoku and healthy leaves. Although little is known about the chemical composition of FM, it appears to be derived from the inner vessel wall layer of about 100 nm in thickness. On IR 28 and Te-tep leaves, the disruption of cellular organelles was also observed. The size of the bacterium in the vessels of Kogyoku, IR 28 and Te-tep was 1.25×0.50μm, 1.03×0.42μm, and 1.05×0.41μm, respectively and the bacterial cells which were not enveloped by FM were significantly larger than those enveloped by FM. From these findings, it is concluded that development of fibrillar material may be associated with the resistance expression of a variety to bacterial leaf blight.
    Download PDF (1969K)
  • Hiroyuki HIBINO, Tomio USUGI, Yasuo SAITO
    1981 Volume 47 Issue 4 Pages 510-519
    Published: September 25, 1981
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Leaf samples were collected from wheat, barley, oat and rice plants infected with wheat yellow mosaic virus (WYMV) or wheat spindle streak mosaic virus (WSSMV), barley yellow mosaic virus (BYMV), oat mosaic virus (OMV) and rice necrosis mosaic virus (RNMV), respectively, and leaf cells were examined under an electron microscope. Complex membranous bodies, and pinwheel or cylindrical inclusions were developed in the cytoplasm of leaf cells infected with each of these viruses except OMV. OMV produced pinwheel inclusions, but no membranous bodies. Pinwheel inclusions in host cells infected with each of other four viruses than OMV were composed of single-layered plates 11-13nm in thickness. Plates in the OMV infected cells showed 3 layers 9-11nm in thickness. These facts indicate a close relationship among WYMV, WSSMV, BYMV and RNMV. OMV may be rather distantly related to them.
    Download PDF (2801K)
  • Kunio KAWAGUCHI, Keiichi OHTA, Masao GOTO
    1981 Volume 47 Issue 4 Pages 520-527
    Published: September 25, 1981
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    An antibacterial substance inducing growth inhibition of Pseudomonas solanacearum on agar plates was isolated from strawberry leaves by Sephadex G-25 and Avicel column chromatography. The substance was identified as β-D-glucogallin (β-1-O-galloyl-D-glucose) by paper chromatography, UV absorption spectrum patterns, and acid hydrolysis for determination of the components. The β-D-glucogallin contents of strawberry plants positively correlated with the antibacterial activity in terms of inhibition zone. In assays during the period of one month after inoculation, no detectable change was observed in the content of β-D-glucogallin as well as the antibacterial activity. Extracts taken from younger leaves inhibited the growth of Ps. solanacearum most effectively, those from petioles being next. Extracts from stems and roots showed a lower inhibitory activity compared with the above mentioned. Antibacterial activity of the tissues varied depending on the plant age and growing seasons. The crude extracts from strawberry leaves inhibited not only growth of Ps. solanacearum but also that of some other bacteria such as Ps. meliae, Ps. syringae pv. pisi. Ps. syringae pv. lachrymans, Pseudomonas sp. from Ficus erecta, Ps. andropogonis and Xanthomonas campestris pv. oryzae. No growth inhibition was observed against the other pathovars of X, campestris, erwiniae and corynebacteria. However, production of extracellular polysaccharides was significantly depressed in most of the pathovars of X. campestris.
    Download PDF (383K)
  • Hideo ISHII, Akira YAMAGUCHI
    1981 Volume 47 Issue 4 Pages 528-533
    Published: September 25, 1981
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    High correlation was observed between conidial germ tube length and number of septa formed in the germ tube of pear scab fungus (Venturia nashicola). Germ tube elongation of sensitive conidia, obtained from leaf lesions, was remarkably suppressed by thiophanatemethyl or benomyl. It was considered that these fungicides act as antimitotic agents to the fungus, and consequently inhibit the septal formation and germ tube growth. As a result of testing for the degree of fungicide resistance by several methods, it was revealed that the “weakly resistant” isolates as well as the “highly resistant” isolates exist in the field. In the artificial inoculation, the “weakly resistant” isolate could also produce sporulating lesions on the Japanese pear leaves treated with thiophanate-methyl at recommended concentration. These results show that the “weakly resistant” isolates play an important role in poor disease control in the field as well as the “highly resistant” isolates.
    Download PDF (294K)
  • Katsuhisa FUKUNAGA, Iwao FURUSAWA
    1981 Volume 47 Issue 4 Pages 534-540
    Published: September 25, 1981
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Conditions for infection of turnip protoplasts with radish mosaic virus (RaMV) and its RNA were investigated. Up to 90% of protoplasts were infected with RaMV in the absence of poly-L-ornithine (PLO) when protoplasts were inoculated with 10μg/ml RaMV in 50mM K-citrate-phosphate buffer, pH5.0. About 35% of protoplasts were infected with 0.5μg/ml RaMV RNA together with 1μg/ml PLO in 25mM phosphate buffer, pH5.8. Few protoplasts, however, were infected with RaMV RNA in the absence of PLO, and the efficiency of infection was greatly enhanced by the addition of PLO. RaMV antigen was detectable 16hr after inoculation and the percentage of fluorescing protoplasts continued to increase up to 36hr. The number of virus particles was estimated to be 1.5×105 per infected protoplast at 48hr after inoculation.
    Download PDF (337K)
  • Yuji NAGAI, Taeko TAKEUCHI, Hiroshi TOCHIHARA
    1981 Volume 47 Issue 4 Pages 541-546
    Published: September 25, 1981
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    An unfamiliar mosaic occurred severely in 1978 on sweet pepper (Capsicum annuum L. cvs. New-Face and Shin-Sakigake) in protected cultivation at Nozaka, Chiba Prefecture. The diseased plant showed severe mosaic symptoms on young leaves and yellow mottlings or streaks on fruits, and the disease appeared to be caused by one of the strains of tobacco mosaic virus (TMV). This virus was identical with tomato strain (T) or ordinary strain (OM) of TMV in the morphology of the particle, thermal inactivation, dilution end-point and stability, but it caused severe mosaic symptoms on all the sweet and pungent peppers tested including several TMV-resistant cultivars bred in Japan, USA, Holland and England. Although the virus never infected tomatoes, it induced very small local lesions on leaves of Nicotiana glutinosa and was latent on Nicotiana tabacum cv. Samsun. This virus was serologically different from both TMV-T and TMV-OM, though these viruses had some common antigens. Therefore, it was concluded that the disease was caused by a new strain of TMV. For the virus, the name, the peppre strain of TMV (TMV-P) was proposed.
    Download PDF (2430K)
  • Shinsuke SANO, Tadao UI
    1981 Volume 47 Issue 4 Pages 547-554
    Published: September 25, 1981
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    The effects of carbon and nitrogen concentrations or C/N ratio on the macroconidial characteristics of Fusarium solani f. sp phaseoli were studied. The macroconidia were produced on the modified Czapek agar medium containing various concentrations of glucose (C) and NaNO3 (N). Eleven among the 14 conidial characteristics were affected by C and C/N ratio; high C and high C/N ratio decreased the pathogenicity, conidial length, microbody area, total nitrogen content, alkaline phosphatase and catalase activities. Conversely, they increased the GT50, conidial width, lipid body area, β-1, 3-glucan and total carbon contents. Lipid content was affected only by C/N ratio; high C/N ratio increased the content. Vacuole area and acid phosphatase activity were affected by N; high N decreased the area and the activity. It was revealed that the conidial charactristics are highly correlated with the Cm/Nn ratio, where C and N represent content of carbon and nitrogen, respectively. The exponents, m and n, are appropriately given depending upon the conidial characteristics. It was also established the regression line of the conidial characteristics on the Cm/Nn ratio. Analysis of variance showed that the degree of conidial characteristics at the various Cm/Nn ratios were significantly different (P=0.05). It is suggested that the conidial characteristics are significantly influenced by the Cm/Nn ratio in the medium.
    Download PDF (907K)
  • Yoshihisa KOHNO, Minoru WATANABE, Daijiro HOSOKAWA
    1981 Volume 47 Issue 4 Pages 555-561
    Published: September 25, 1981
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Permeability changes in rice leaves inoculated with Xanthomonas campestris pv. oryzae were investigated by measuring the leakage of electrolytes and 14C-assimilates to gain an understanding of the mechanisms of pathogenesis. In experiments with detached rice leaves, pieces 6mm in length were incubated in the bacterial suspension (about 108cells/ml) for 72hr at 25 C in a shaking condition. The bacterial suspension was then replaced by distilled water, continuously shaken for an additional 4hr at 25 C, and the conductivity of this bathing solution was measured. The electrolyte leakage was 2 to 3.5times higher in inoculated susceptible leaf pieces than in the non-inoculated control, but was only 1.4times higher in resistant leaves. No similar increment of electrolyte leakage was observed with heat-killed bacteria, centrifuged supernatants of culture suspension or bacterial suspension to which chloramphenicol had been added. From these results, it is clearly evident that living bacteria can induce permeability enhancement of rice leaf pieces. In experiments with attached rice leaves, periodic measurement of the leakage of electrolytes and 14C-assimilates revealed a significant increase in susceptible leaves from just prior to symptom development, and a slight increase from the same time in resistant leaves.
    Download PDF (433K)
  • Tsuneo WATANABE
    1981 Volume 47 Issue 4 Pages 562-565
    Published: September 25, 1981
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Download PDF (885K)
  • Hiroyuki HIBINO, Tsuneo TSUCHIZAKI, Yasuo SAITO
    1981 Volume 47 Issue 4 Pages 566-570
    Published: September 25, 1981
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Download PDF (989K)
  • Norifusa MATSUO, Nobuaki MATSUYAMA, Satoshi WAKIMOTO
    1981 Volume 47 Issue 4 Pages 571-574
    Published: September 25, 1981
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Download PDF (691K)
  • Hirotaka KUWATA, Keise SHIMADA, Jun-itsu CHIBA, Suesaku CHIBA
    1981 Volume 47 Issue 4 Pages 575-576
    Published: September 25, 1981
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Watermelon grafted to bottle gourd stock showed sudden wilt symptom by the artificial inoculation of Fusarium oxysporum f. sp. lagenariae at the extremely low level of inoculum density, at which not only the bottle gourd seedlings but also the stems or roots of rootstock exhibited no marked symptom. The sudden wilt of the grafted watermelon was also brought about by the artificial inoculation of only a narrow part of root system of the grafted plants.
    Download PDF (153K)
  • Kiroku KOBAYASHI, Norio KONDO, Tadao UI
    1981 Volume 47 Issue 4 Pages 577-580
    Published: September 25, 1981
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Download PDF (135K)
  • Tomio USUGI, Yasuo SAITO
    1981 Volume 47 Issue 4 Pages 581-585
    Published: September 25, 1981
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Download PDF (1599K)
  • Mitsuya TSUDA, Tohru WAKI, Masatoki TAGA, Akinori UEYAMA
    1981 Volume 47 Issue 4 Pages 586-588
    Published: September 25, 1981
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Download PDF (114K)
  • Hiroyuki HIBINO, Tsuneo TSUCHIZAKI, Yasuo SAITO
    1981 Volume 47 Issue 4 Pages 589-594
    Published: September 25, 1981
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Download PDF (1505K)
feedback
Top